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Post by pxguru on Jun 18, 2016 10:01:20 GMT
I don't think you did all of this today! I think the bore was a bit tight all along. Looks like a general overheat as the scores are all the way round. I'll bet the exhaust side of the piston is worse. Keep it under 150 C most of the time and it will loosen up itself. Had it ran it for a few hundred miles before taking the head off it would have looked a little better. If you can't see any cracks in the piston, I suggest to scrape all the aluminum off the rings. Rub the bore over with some 600 grit. Same with the piston. New spark plug (probably cracked inside as well as plated in ally) and then put it all back together. Recommended starting jetting; 160AC BE3+2 135MJ 48/160 pilot btw; this was not just running a bit lean, this was way under. Looks a mess but won't run any different. Might even be faster now Edit; Once it's running and jetted right. If the thought of a scuffed up piston is too much to bear. it could have a hone and a new std piston or a 1st oversize and re-bore if you can get one. But if it was mine I would just run it till it was done in.
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Post by sime66 on Jun 18, 2016 11:23:22 GMT
Might even be faster now behave! Seriously though, thanks for advice, pxguru; I’ll get it going again with what I've got after some TLC, and use the toned-down jetting you suggest above to start with. I won’t go into the piston/barrel damage/options here yet because my immediate problem below is the one I could do with some advice on, which is getting my hands on the piston, as follows: I took off the outer circlip and tried to push the gudgeon pin towards me from behind, but it didn’t want to shift, so I left it there for now. To clean it up properly I reckon I really do need to get the piston off; are there any tips or tricks to do this in-situ? I think I’d have better access if I take the back wheel off, but does the pin only go in one direction? If so, is it in or out? Should I try to take the other circlip off and push it through the other way – away from me? I don’t think I can safely heat it with all the petrol about; would a boiling towel maybe help warm it up and slide it though? Would dropping the engine, just at the main engine bolt, solve it? I’ll look for clues on the net later this evening if no suggestions; I quickly looked at the ScooterWest teardown video, but he knocks the crank out before he takes the piston off. That’s going to be first job, to get it indoors to get it tidied up, but for now I’m temporarily stumped with that little teaser. - Any clues? Anyone?
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Post by pxguru on Jun 18, 2016 14:24:18 GMT
Quickest way for me is to take the back wheel off, remove circlip both sides, heavy rag in the crankcase, pitson at BDC, and lightly tap through with a drift from the outside.
While you have the piston off, do another heavy chamfer round all the ports and edges. Helps the oil not to get scraped off.
Just for a measure of what running weak is; one MJ less than optimal will run hot and rough but probably faster, two MJ less than optimal will go well in the low gears then seize up like this.
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Post by vespasco on Jun 18, 2016 15:58:34 GMT
holy crap! Now you've got a good idea of where your limits are
i watched the video and you were really were in high rpm in 3rd gear for a long time.
there does seem to be a lot of melted ali here and there. i hope it all cleans up ok.
yeh, remove both circlips. try from either side if it won't budge.
good luck
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Post by sime66 on Jun 18, 2016 17:51:59 GMT
I know, I know, I know……………………. it wasn't my best performance today Limits have certainly been identified – mine and the motor’s (for me it used to be power tools, now it’s my box of jets). The staying in 3rd for a long time was deliberate and for three reasons: 1. There’s a slight uphill on the dual carriageway to start with, and I know using 4th before or during that just buggers my run revs up. 2. I really wanted to get 9,000rpm on film – I got 8,980 and a very hot engine instead. (and BTW, sod the 9,000 in 3rd when I get it going again; I’ll stay safe now). 3. I was watching my CHT all the time and it was fine, from the other day WOT temps at high 3rd fan revs are good. When she blew I was just considering going to the next junction past my usual one, to see how high I could get the revs in 4th; the temps were still fine and I was trying to get revs and speed higher…………………(then she blew) By the time I was in 4th I think I was already buggered; she never went over 100kph or 134⁰C on CHT, but the writing was on the wall for exhaust gasses and the unfortunate outcome. I’d just been starting to read-up about the different was EGT goes too. I’m glad you didn’t nag me about my jetting as well vespasco; I knew I was taking a chance, but I was tired of the endless tweaking and chasing the seasonal weather changes; I was about to say I hope I get the Summer jetting sorted before I need to start doing it all again as Autumn cools down. I also thought double-rich meant I had room to play, and that I’d see some warning in time. Also that the 130 (from 160) of the 40/130 might have allowed me the AC tweak (40/130 is richer on my chart too) – I’m calling it an AC170, but it’s a spare AC160 with a drill run through it (I'd also noted you were on an AC185 pxguru, - but I see now, you'd also gone from 48/160 to 50/120). It wasn’t a reckless choice, it was considered but certainly proved to be unwise, and of all things, it was due to my impatience in the end. I will add, and I don’t know why, the plug was loose when I went to look at it; I did NOT leave it loose, it must have come loose during the recent shaky runs (because of CHT ring?) or during this seize – I don’t know if that’s possible, or a contributing factor that makes my jetting less of an obviously outrageous decision, but there it is out in the open anyway. The head has cleaned up fine and the threads are good. I know doing three leaner-tweaks was a poor decision; I’m not trying to dodge that, but if it’d worked we’d all be slurping ice creams and congratulating ourselves…………. That’s the post-mortem for now, so to the cleaning up. I’ve made a start on the barrel, which is looking very promising; I’m pretty happy that will be OK. If that’s OK, all else can be easily fixed. Thank you both for input with getting piston off; I will tackle that next job. I knew the forecast for tomorrow was poor (which is why I did the jetting last night and the early start this morning), and I don’t want water in my engine now, so this morning I left it with a rag in crankcase with piston down on top, a rag in the exhaust, and it all covered with a plastic bag, the side panel on and the scooter cover too, so I’ll leave it like that until we have a dry morning, which I don’t think will be tomorrow. Now that I’ve had some clues about getting the piston off, I’ll approach the subject of piston itself: · I’m less confident that can be cleaned up, but trying that’ll be the first plan of action, now hopefully I can get my hands on it. · I have a spare piston from a soft seize a few years ago, when my long-since-sacked ‘mechanic’ put a new piston in when I wasn’t convinced it really needed it; I’ve kept it and I think that one would clean up better than the one I’ve just heat-treated and scrubbed. · I don’t yet know what the rings are like; if they’re scored, got molten aluminium on them, or otherwise past it. · A new DR piston and rings is about £45 posted from SIP….. · A Grand Sport piston, rings, gudgeon and clips is £90 posted from SIP….. · I really do not think I’ll get anyone to rebore this cylinder, nor do I think it will need it. I had such a problem getting anyone to even attempt to skim this barrel; it is already too thin and scares everyone I ask, especially with the skirt already cut out so much on the thin wall. SO I don’t think an oversized piston etc is needed or do-able. First choice is reusing this one from today though; I’ll update when I’ve got it off and had a look…………… Here’s first bash at cleaning barrel; I’m out of 600 grit now, so I’ll have another bash when I do the piston – I think this will be OK:
pxguru; rechamfer the barrel ports, or both? – I don’t think I chamfered the piston before; should I have?
She'll soon be back on the road; what could possibly go wrong...................
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Post by fredperrybruce on Jun 18, 2016 19:14:40 GMT
Hi,, Sime66 sorry to hear about the little seize you had ,, just to give you the heads up I'm sticking my DR 180 kit on ebay tomorrow eve. It's a complete kit Cylinder head,barrel,piston,rings gasket had been on my scoot for approx 2 years I changed the rings 1500 miles ago . Ran like a dream but taken off for a Polini no deep scoring or seize ever. Starting bid 0.99p No Reserve .maybe some use to you?? Best of luck with your build
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Post by shipscat on Jun 18, 2016 23:01:20 GMT
feckin si carbs i've been having issues trying to sort my si 1/8 throttle 4 stoking i've come to the conclusion that they are only good on their original applications when you start upgrading cylinders/exhausts using the si you need some kind of si magic to get your engine running correctly (or people who have tuned their scoots are running si carbs are kidding and tell everyone how good they are) i can't count the number of threads post's and info i've looked at all over the web , all of it contradicts the other , even the dellorto carb book doesn't cover the si model and the atomizer numbering is just c**k meeow !!!
all that aside i'm glad you didnt't get hurt
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Post by pxguru on Jun 19, 2016 4:41:03 GMT
Barrel is cleaned up lovely already. See not so bad. little bit more and will be good as new. You would get a rebore out of that if you ever need it, skirt is not so thin.
Call me old fashioned but I would run the same old scuffed up piston until it does actually crack or sounds so bad it should be cracked already. The big advantages are; this this one is already run in, it will perform just the same, the new scores will help hold oil, there is no damage to the crown, all the high points are now knocked off, if it seizes again who cares? and most importantly....it still owes you money.
Yes, you should have heavy chamfered the piston ports as well. It's all a learning curve.
Shipscat, As said many times SI carbs are more complicated than they look. Changing any one thing affects everything else in some way. There is way more jet overlap than in a needle carb. For a non-standard set up it takes a while to get right but takes some patience.
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Post by sime66 on Jun 19, 2016 7:09:05 GMT
FPB; thanks for pointing it out; I’ll keep an eye on it. There was one on FB last week for £50, which I didn’t bother with. Couple of people interested though; you might do better there to save your Ebay fees. They’re still only £84+12 from Italy though, and if anything I’ll only need a piston*; I’ve got spare heads, and this barrel will be OK, which is a relief because of the work and expense of it: I couldn’t have been arsed to tackle all that again right now.
Shipscat; this can’t be blamed on the Si carb. To me carbs in general are proving to be a bleedin’ faff to set up properly, but that’s only because I’m still learning, and because I was tired of the never-ending tweaking and testing I lost my patience with it and made a mistake. My own opinion, due to my inexperience and lack of time I’m willing to spend setting up a carb, is that I’ll just get it how I’m happy with it and keep a little further away from optimum next time, where it was a week or so ago would have done me fine all Summer; I didn’t even need this final tweak and should have left it as it was, rather than push it closer.
Pxguru; a little time to contemplate and cleaning-up the barrel a bit, and I’m happier with things. I honestly don’t really care about the money, if I did I’d have packed it in long ago, but re-doing the work was my first thought; I couldn’t handle that at the moment. Yes first choice is to re-use the old piston* if I can; we’ll see how she comes up with a bit of TLC – and I’ll do the chamfers – DOH! Two thoughts overnight: I was probably getting low CHT readings too, due to the loose plug, whether or not the loose plug was contributing to the temps. I’ll have a look at the clutch while I’m in the pits with the wheel off; might as well get all the bad news in one stop.
If it seizes again who cares!
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Post by pxguru on Jun 19, 2016 8:59:41 GMT
And also while you have it in the pits, it might be a good chance to get rid of some of those revs and swap them for a bit more torque to pull 4th better. Will be faster to ride overall with less rpm. Its those extra exhaust ports that give the extra revs. As I remember you have a packer and 2 gaskets. If you take at least one or both gaskets ( more than 0.2 mm) off the base and that will the tighten the squish a bit more. The max rpm will be about 500 rpm less but 4th gear will pull a few hundred rpm earlier. Less low rpm mixture loss and increased compression will make it pull a bit harder all round.
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Post by sime66 on Jun 19, 2016 9:11:36 GMT
I've just been looking at those exhaust ports myself just now; remembering that I shied away from it before! (and I have got an expensive new Dremel and flex to play with). I've just re-read yours; you're not saying I should do the exhaust ports, just the barrel height and squish. The other bit; give me time to cogitate - - I've got 2mm ally packer and 0.2mm copper gasket. From memory my squish is about 1.4mm; I'd have to check back. I am not looking for more work though; I've had enough of all this for a while, and want to just ride safe and enjoy for a few months. I don't want an extended pit-stop until Autumn really. 4th-pulling torque would be good though, but what about 'less low rpm' pulling my big old frame up these hills?
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Post by pxguru on Jun 19, 2016 9:37:58 GMT
This is no messing about or sticking plasters at the ready When you put it back together forget the copper gasket, only gasket sealer on the packer (both sides). Squish will then be 1.2 which is still in the normal zone. I think this is a worthwhile easy change that you wont want to put back. If you read it again I said "Less low rpm mixture loss", opening the transfers later loses a bit less out the exhaust port(s) when at lower rpm. I'm still over 17 stone so I know all about pulling big frames up hill.
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Post by djloone on Jun 19, 2016 10:10:17 GMT
Looks like its cleaning up well Sime...def reuse LOON-E
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Post by sime66 on Jun 19, 2016 12:11:46 GMT
Cor blimey, she put up a fight! Have just returned from an hour’s mud wrestling to get the piston off; ain’t it always the littlest jobs that take the most time and swearing – and my neighbour, bless her, came out to tell me I look wet. I’ll do photos at the bottom, but here’s my observations: · Although she looks horrible, she actually feels quite smooth, except for the muck on the crown and the scoring near the exhaust, so before long the ‘after’ photos will show it looking ready to re-use – if that’s still the plan when these photos are posted. · The crown is not pitted or cracked, but there’s quite a lot of (molten ally) deposits corresponding with the exhaust zone; I guess I’ll be able to sort it out though. · The exhaust zone is also where the worst scoring is, but it looks worse than it feels as I say. · Unfortunately, the top ring (which seemed more fragile than the bottom one – due to the heat?) broke in the fight to get the piston off; I was gripping it as best I could to protect the con-rod whilst encouraging the gudgeon pin out. Amusing anecdote: After I got in soaked and I stripped off, I went to lay my tools out in the kitchen to dry them out, and I got the piston on my desk for inspection, noticed a bit of ring missing, went through all my tools, the kitchen surfaces and floor, and ended up having to put my wet stuff back on and get back out in the pouring rain to find the missing bit of ring, to be certain it wasn’t inside the engine, on my hands and knees in the puddles – Found it!!!(the job could have got very tiresome otherwise). Two immediate options spring to mind: 1. I have an old spare (I guess from the same previous ‘soft seize’ a few years ago); it’s part-worn and I could check its ring gap, and maybe use it. 2. I could get a new set of rings and have a bit of running in whilst setting up the carb again. Point to note here is that the surviving ring is pretty scored, and maybe fragile too; I’ll do photos of it at the bottom. Anyway, I’ve a nice liitle indoors job of cleaning this piston up now, if we think it can be saved, while I decide what to do about the rings. Here’s some pics; looks worse than it feels: Left to right; scored bottom ring, broken top ring, and old spare ring:
Close-up of scoring on ring:
Deposits on crown around exhaust (yesterday's picture in the natural light, previous page, shows it better):
skirt (ouch!):
Might as well have the head too:
loone; the barrel I’m happy with, this piston I’m ready to give some good lovin' if the team still reckons it’s worth it now we’ve had a look. BTW; You know you were going to use my notes for your carb setting up? – give this last bit a miss, eh?
Pxguru; yes I did rush through your last post whilst I was waiting to see if the rain was going to stop, or if I was going to bin the job for the day. I still haven't stopped to give it proper attention, I’ll have a proper read later, but it sounds simple enough; I’ll see if the reasons why it works make sense to me later as well, but I'm up for it. My biggest worry at the moment is fighting this piston back on; that was stiff. Edit:
For info; I’ve measured the ring end gaps as follows: ‘scored bottom ring’ (from Saturday seize) = 0.6-0.65mm; ‘old spare ring’ = 0.7-0.75mm – those are 25mm down using piston, I can’t see that the depth matters but just in case…. I’ve dug out my DR instructions, but can’t find anything on ring gaps. I’ve also had a quick look on Internet; on Not-so-Modern-Vespa I’m seeing 0.25-0.4mm as the acceptable range for Ps, on LML Owners I’m seeing 0.3mm used for a DR177; which suggests these are both worn. I need to check those figures elsewhere to confirm. Unfortunately I didn’t measure it when I put the kit together, so maybe they're big gaps to start with, or maybe tidying the barrel marks up has made a noticeable difference. This might have some influence on deciding whether I need new rings or not. That scored, possibly brittle one bothers me a bit too.
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Post by djloone on Jun 19, 2016 15:45:40 GMT
Ha yep mate but these things are too be expected from the awesome italian bits of engineering ...been out for a short run on mine today..still dont feel right...think im gonna spend a few quid and have it set up by a man who knows his stuff on the dyno (im not going for power or speed but safe chugging miles)...all your bits look like they can be saved/reused...get it banged back together asap and get some dry/warm/good miles in while its summer (supposedly lol) LOON-E
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Post by shipscat on Jun 19, 2016 16:54:39 GMT
the gaps your speaking are at installation .0004" to every inch of bore diameter i read in a vespa service manual the max admissible ring end gap after use is 2mm this is for standard engines tho (tried to copy page from pdf file and it wont work)
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Post by vespasco on Jun 19, 2016 18:41:28 GMT
From the pages of Piaggio, for a 200 model cast iron cylinder - Piston ring gap on assembly = 0.25mm - 0.4mm 2mm max permissible Measured 25mm down for a 125 cylinder, 30mm down for a 200, with ring gap at 90' to gudgeon pin
I would also try to re-use everything. I know you'll clean them up nicely and it will all go again. run it rich and take it easy. You'll be back on the road before you know it.
No lecture about the jetting. I've still not sorted out my carb properly yet. But i know its running rich. I've only just got round to ordering a new set of (BGM) jets so i can come down a size on the MJ. I might just leave it running rich now!
One question, a little unrelated....how does your change of idle jets affect your starting? Or is there no problem after adjusting the mixture screw correctly?
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Post by shipscat on Jun 19, 2016 21:29:04 GMT
vespasco i tried the bmg main jets i found the part that pushes into the mixer tube are too small i.e put jet in mixer tube jet falls off into the carb some creative thinking required if you dont want to take the carb off and turn it upside down to get the main jet out too rich idle jet no choke needed to start from cold and hard to start when warm
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Post by sime66 on Jun 20, 2016 3:33:44 GMT
Chaps, my internet has been down since yesterday evening, now (4am) it’s really slow, and won’t load big pages like my Flikr album, so I can’t post photos till it’s sorted. The piston has come up really well, but I can’t post the photos. All the deposits are gone from the crown, there is a little pitting, and a lot of the scores from the skirt are greatly improved; it ain’t finished, but it looks more useable to me now. I can do my chamfering, and I can retrieve the 0.2mm copper gasket and clean the surfaces on the casings (if it isn’t hosing it down) – I’m losing the gasket, so Deck Height and port timings changed as well as squish and compression ratios; can have a play with new numbers….there’s stuff I can get on with…… I won’t be doing my morning Net wanderings, but I can hoik my Haynes out in the morning; yes that 0.25 to 0.4mm is what I believe it says. I can’t re-use the broken ring! I don’t know whether to use this old one and the maybe-brittle, scored survivor, or get new rings. I can’t order rings without Internet, so hope it’s all sorted soon, but it isn’t worth getting annoyed about. I found them yesterday afternoon; about €10+p&p from SIP or £12.50 posted from UK supplier, so no worries – other than the running in, so hoping for opinions on that one. BGM jets are fine, but size-wise they didn’t compare accurately with INC; when I’m in the transition between them, at 140, from memory an Inc 140 is more like a BGM 142, or the other way round; it’s a few pages back and I can’t open it at the moment. Opening the jet a bit to stop it being loose in the stack is easy (until you snap a bit off), but check the sizes when you go from one to the other if/when you have to. I’ve had no problems starting, cold or warm, with this new engine (it won’t start now, but that’s not jetting; it’s because the barrel is in my front room in a box). Once I had my Pilot and Mix correct, the starting was sorted; too rich is what buggers the warm starting, or that’s what I believe to be the case; as I say, mines been good since I did that bit of the carb setting up waaaaay back. What else? Keep posting; I can read even when I can’t reply, and I’m keeping this page open and logged in, hoping to see it come to life sooooon. I might see if I can email you in a minute vespasco, but with the hours you keep, it’ll probably all be fixed and forgotten before you roll out of bed! Can I freeze the gudgeon pin to help reinsertion? Getting that back in with engine in frame is bothering me. Anyway, I only got up to see if Internet was working; going back to bed for an hour………………..
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Post by pxguru on Jun 20, 2016 3:36:17 GMT
Must have been hard to get that piston off. Rings don't often get broken that way. The old ones would have been ok to continue but I would put the old ring back in the same position and the same way up (black side up) and the new one in the other position. Had a re-think on the Recommended starting jetting; 04slide(unblocked) 160AC BE3 135MJ 48/160 pilot. We can start again from the beginning. One thing to remember is that anytime anything is changed in the carb, the pilot jet idle mixture and progression air needs to be set up again. Get it back together and sorted, will soon be the weekend
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Post by sime66 on Jun 20, 2016 4:08:51 GMT
I'm still here........ 1) 'New one' as in the 'old spare' I kept from before, or a new one? 2) And you've seen, and are not concerned, what I said about how brittle the other one was? The survivor might yet break getting the rough edges off, or it back on; I’m surprised it didn’t break getting it off – the top one broke a second time removing just the three-quarters of it. I'm a little concerned about losing bits of ring up my crank if I reuse the survivor. I’ve noted new jetting start point; thanks. If/when she fires up, ticks over, and gets me round the block with no nasty surprises, I'll get my head round having to start the carb set up again - at least this will remind me not to lose patience with it again.
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Post by sime66 on Jun 20, 2016 4:39:43 GMT
Seems to be back! - I was getting withdrawal symptoms. This isn’t finished; I’ve got more wet and dry on the way, but I reckon it’s come up OK. I could go lower to get rid of the pitting, or leave the crown alone now; likewise I could get the skirt smoother, or leave those designer oil channels. What do you think of it so far……………….
…..rubbish!
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Post by pxguru on Jun 20, 2016 5:47:07 GMT
Looking just fine. A few months of use and you will have forgotten all about it. Guys sometimes get excited about these marks on their pistons but they don't make any differance. Those little pock marks on the top are a real battle scar. Will be ok but they mean it was really very weak. Detonation marks. Must have been pinking like mad. I think it has not been running as well as you thought for a while. It's all just jetting. Go back to the start (04slide(unblocked) 160AC BE3 135MJ 48/160 pilot) and it will be easier this time. Next time I am in the same place as the tourer I am going to do the same, I am not happy how it ended up on an 185AC and want it back on a 160.
Use the old ring in the exact position it was, it will not be damaged and will bed in again very quickly. And use one of the 'new' rings that you already have.
Now get it back together. Gudeon pin in the freezer will help no end. Should be running within the hour!
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Post by sime66 on Jun 20, 2016 6:36:12 GMT
....a few days; by the weekend. I've got catching up on other work that has to take priority now, and there's a few jobs left to do here; no rush and no need to rush. I think I buggered my CDI too (maybe also HT/plug cap), but I have spares, and a new Ducatti one on Old Faithful too; needs checking anyway. Stator is fine (readings at bottom of this post). I think my CHT was reading low on a loose plug, and that's why my progression temp was low, and no downjetting was required, let alone my triple-whammy! Lose 0.2mm gasket, noted; which rings which way, noted; new jetting, noted; chamfering piston, noted - thanks for those. A few months will do me fine; engines coming out in Autumn after MOT; I've got engine mounts to do and some work on the frame around the engine and rear wheel, AND the disc forks malarkey to tackle. - Can she last till then? can the clutch last till then? - Lets hope so, eh. Suspected dodgy CDI:
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Post by pxguru on Jun 22, 2016 3:20:58 GMT
How's progress? Back together yet or you couldn't possibly make any decisions to put it in or leave alone until after tomorrow is over?
The seizing would have no affect on the CDI. Is not often that they just work badly, is usually running or not running. Always good to have a spare handy though.
I think the lose plug could have added just enough to the whole problem. Low CHT readings for sure, hard to guess how much but significant no doubt. The other thing is a lose plug might let a little bit of air in, maybe enough to add to the problem. All very unfortunate but won't have cost you anything but time and a new plug.
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Post by sime66 on Jun 22, 2016 6:00:03 GMT
It’s all cleaned-up lovely, and ready to go back in; good as new, but I am waiting for some new barrel studs and a few other little bits. I was waiting for more 600grit, but it didn’t turn up in time, so I’m going ahead with it as it is – photo below. I’ve yet to put the rings on, but I have bought new spares so as not to hold me up if I break one of the used ones, obviously hope they remain spares! If the 600 grit doesn’t turn up while I’m out today, this evening I’ll rinse all the grindings off for the last time and fit the rings; I’ve only been snatching time on it between other stuff so far this week anyway, and it’ll be in tomorrow or Friday, in plenty of time for the weekend - (gudgeon pin in freezer). The reason two of the studs came out is that when I retorqued it during running-in, the nut had hit a slightly damaged thread and was turning the stud in the casings, not turning the nut. Knowing these casings threads are precious, I decided to get new studs, which I’ll Loctite in more thoroughly this time. I have FOUR spare CDIs! – none of which give the same readings, so I decided to just give this one a try to see if it was still good or not; for interest (comparison with others?) I’ll post my readings below, when I’ve finished rambling……… I ‘have a theory’ as follows; there is a 5 kΩ resitor in the cap, which will give me dodgy readings if I measure HT resistances from there, so a damaged cap might give dodgy readings, and moreso if you don’t take the HT lead off and measure directly from CDI. Not important, but noted for future. I have spare caps too; old and new, so if it is that it won’t be a problem. My rev-counter is off HT, so I'll soon see if it's gone wonky. I was a little concerned that the head looked quite oily (grey), when I removed it after the seize, which I kept to myself but showed in the photos to see if anyone else mentioned it; but anyway, while I was changing the jetting I let the oil drain, and put fresh in. the drained oil is beautiful; dark brown, no fuel-smell, no rainbow, no separation overnight, no big foreign bodies at bottom or attracted by magnet, so that’s all good. I’ve got the copper gasket and all the muck off the casings and cleaned them all up ready too, and I’ll use the Hylomar 250 both sides of just the 2mm spacer. That’s it really I think; let me take the time I need to satisfy myself that I’ve thought of everything, and got everything I need to go out, when I’m ready, and do the job properly in one go; you’ve done this hundreds of times, me – not even half a dozen, and never with engine still in.
(I'll give the chamfers another go with an old worn-down Dremel flap wheel if the 600 grit doesn't turn up today.)
Starting Jetting (for my reference): Si 26/26 (drilled to 2mm), Polini vortex, RamAir filter, and.... 48/160 138 – 135 - 132 BE3 – BE3+1 – BE3+2 AC160 – AC170 04(Obstr) – 04 – ?
Another quick point; do we still favour the Viton brown and metal seal for older engines? I seem to recall some recent discussion that might have said otherwise. I ask because I’d like to have a spare and wasn’t sure if we’d had a rethink. Beedspeed have Viton (listed but not necessarily sent), Wasp have Rolf; but the one I got from Beedspeed before could have been any make; it was loose in a plastic bag floating about with all the other stuff I’d bought, and unbranded so could have been anything, so I thought Wasp’s brown (NBR) and metal Rolf might be better.
www.wasp-performance.co.uk/onlineshop/prod_3579361-Crankshaft-Main-Oil-Seal-Clutch-Side.html
www.beedspeed.com/vespa-seal-drive-side-viton-pxperally-p-11948.html?osCsid=rdglfphidkdfgbi2taemcsd6i2
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Post by pxguru on Jun 22, 2016 12:41:12 GMT
All looking nice and clean. That barrel is looking super shiny. Looks like it is all ready to go. Ready for all the jetting to start again soon. Will be easier this time though.
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Post by sime66 on Jun 23, 2016 9:55:34 GMT
She’s Alive!!!!!It took two hours to get it all back together outside; the hardest bit was that bleedin’ gudgeon pin, which I expected. Everything else went as planned. On third kick she fired up, big puff of smoke, a few odd noises, but nothing that bothers me, and which can be investigated if they persist. She pulled away smoothly, she settled down after I put the choke in, which I forgot because I normally do it before I pull away. The film cut itself short, but I went up and down the lane four times, then stopped to see if it would idle, which it did at 1500rpm, so that’s good, but it all needs a tweak (started at 2½ mix, 1½ idle). I only went to about 5-6000rpm (that’s from memory; I’ll check the film), CHT was cool, but that’s no surprise. Conlusion; plenty of tweaking (mainly carb), but nothing to worry about. Here’s a quick film; I’d say don’t worry about noises; I’ll investigate and worry if necessary: ....and lets have no nagging about shorts; I've just been rolling around in the garden for a couple of hours, and ain't getting clobbered-up for two minutes in the lane.
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Post by pxguru on Jun 23, 2016 12:58:29 GMT
Good work! It lives again.
Once you get some long trousers and after a quick run in session, start by reducing the main jet until it revs right out in 3rd. Could be 500 rpm short now it has less packer.
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Post by sime66 on Jun 23, 2016 13:24:33 GMT
Hoping to have a gentle ride early tomorrow, then if all's well, I'll get on the jetting. Thought you'd have me playing with Pilot first, but I'm easy; just happy to have it back! (...even turned-down a bit until I can behave meself )
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