I'd seen the SIP Performance individual ones, but couldn't be arsed with SIP. I'm normally pretty sharp with the purchasing, but I missed that BGM one, and just got mine (Spaco 142, 145, 148 - £13 off Beedspeed) this morning; missed a trick there, but wanted to get them ordered in case I need them over holidays. - Probably won't need them anyway (mine shouldn't be that big; it's under investigation).......
thats without postage ,which to englander is 9.9 euros ,in proper money thats 16-odd quid , tho the cologne wearing smelly scoot centre shippings cheaper =13.80 of our earth pounds , Aah a see were ya got £14 from now . a few decent shops stock em ,so cant be total rubbish ,an if i remember right the scootering thing were a guy in lancs was makin accurate jets ,bgm came off better than dell an on par with sip . well you know the drill ,start with ya 148 n work down , should have a dialled-in scoot by new year . H
if its got wheels n makes a noise I wanna play with it, skateboards included coz "skate-punks rule",
Everything 'SIP' own brand is 20% off on 'Black Sunday' - 20th December; I expect you've seen that. Might be worth a think; though nothing springs to mind for me at the moment.
You're ever so slightly ahead of the game with my jetting though; I'm still too lean on the 150(ish), so that needs sorting before there's any working down. I think that'll be some cautious carb-channel work first. In the mean time I've got it a little richer with the undrilled filter, and this evening I've made another slightly larger again home-made jet, which I'll call 155(ish). Those two changes are to keep it rideable for now, safely until I suss out the reason for it. I don't like the idea of restricting it, so I'd rather have this new 155(ish) jet than the undrilled filter, so might have a swap and see, or both. I'll be happy enough for now as long as I've got some colour and sensible temps (- AND mildly-spluttering!), but I know I shouldn't be that big, so some head scratching and tweaking is needed, but no harm was done, and at least we're once again going in the right direction with it. Whether it's worth Progression plug chopping with these big MJs, before the reason for them is found, I'm unsure, but in any case not much is happening next week; I just want to be able to use it a bit.
Well, that's a relief, some progress at last. Plug colour looks nearly ok, just a bit more will do it. Put in the 155 (ish) and make sure there is good colour across all the the throttle positions. If this is ok then its not so bad and you could run like this for a while.
One thing bothering me is that the first white plug was just above progression range, where the MJ is feeding the atomiser at a low rate. This would mean that there already isn't enough fuel in the MJ well (un-covering too many air holes) and letting too much air in, even at middle revs and low throttle.
The carb has to be drilled out and the float level checked. Hopefully your tank delivery timing is all normal and standard, then that can be ruled out. I am sure you have an issue with float level though.
The fast flow fuel tap is more important at WOT. If things are all ok until well open throttle then it starts to play up, then this is the usual fuel tap problem. Like I did on mine just fitted a fuel pump to make sure there was no issue at all, never, as the fast flow taps are usually not enough in my situation.
The SI carb is really sensitive to float level. If all else fails one of those spacer kits will help. They make it run richer right across the whole rev range but usually too much!
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
That second sentence has filled in the gap for me about how you'd pinned the float level down as the problem. As it happens I do have a set (3mm I think - I'll find and check later) spacers, that were on this carb when I got it; I wonder if Seller had similar problems and gave up. We've got that option up our sleeves anyway. I can also see why they would make it richer now. I'm not sure how to go about checking float level though; this has been on my mind since you mentioned it yesterday – if I take the float chamber top off with petrol connected won't fuel just flow? Do I let it fill, then disconnect it? Just turn it off? Can't quite picture how to go about it. I haven't done much reading lately; I'm sure I could find it if I stopped to look. - **Just thought; it's the same as the level in MJ well - that's it isn't it. I'll have the carb out for drilling, and I'll thoroughly read vespasco's thread and the ones it links to and get familiar with it all while I'm waiting for the bits, and thinking about when to schedule it in. Little indoor fiddly jobs are right up my street, so that should be OK, probably the float level checking is something to do then with the carb on my desk. I think you're saying I should still check my tank delivery time, so I will do that when I take the carb out. We'll hopefully put fast flow taps and pumps on the back-burner for now then; that's good. Long periods of WOT are not really my riding needs anyway, so probably not required for now at least – until I go on my Tour de --- .
A quick couple of night ponderings: If I end up with good results with 150(ish) with carb mods, and back to drilled filter; does that indicate a problem still exists elsewhere, or that the engine is a bit thirstier and free-breathing than expected? I don't expect there's a simple answer; that's why it's a pondering. Is it feasible that the 55 on the Pilot was more important than the air? I think I had a decent colour with a 55, and you ended up with a 55 on your 26/26; maybe I should try a 55 again, and/or get a richer one; there are three richer Pilots left on the chart, the richest being the 55/100. - Probably yes; wish I'd thought of that in the previous night's ponderings, then I could have ordered some when I was getting more MJs yesterday.
I'll go out as soon as it's light enough to put the 155(ish) in and to be able to read my CHT gauge, only for 20-30km, just to see how it feels, what sort of temps I'm getting, and to have a look at the plug after. So it looks like I'm safe for reasonable, sensible adventures over the holidays, and I have several tasks and options up my sleeve to improve and progress – this is good; thank you.
A little less wet or windy today, too dark to check yet, but the rain-radar looks promising, so I'll get out early and do an update when I return.......................
Just a quick thought, might be an issue that your carb is not new. If someone was fiddling with float height there might be a non standard float needle seat or float needle in it. This would cause the problem. I think you could put the whole float top of your 24/24 on it for a test. Never tried it but I think it fits the same.
btw; you get up early don't you? I think your pilot jet is about right. Could be one size out though. You could try a fast idle adjustment of your mixture screw just to check. Set it at fast tickover 1,600rpm or so. And adjust the screw in to just reach the fastest speed then back out a touch. See how the turns differ from the slow idle set up.
2nd edit; You are going to get more practice. When the problem is fixed all the jetting will be a bit out but should end up similar. Maybe 52/140 and 142 MJ would indicate that its all ok now. You might want to take the 160 air corrector off the 24/24 as well. The one on the 26/26 might be fiddled with too.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
I put the ss155 in, and kept the undrilled filter, but it was well-spluttery, so I dropped in to KTM to say hello-you-old-git and put the drilled filter back on, whilst showing off my new engine. These figures and plug are for ss155 and drilled filter, 25km run at various speeds as below. Before recording the numbers, I'll say my feeling is that it was a bit less lively, the temps are better, the plug needs improving – so these (pre-carb mods) tests are getting closer to something safe for holidays, but I am well aware that after the carb mods, we'll be pretty much starting again from #2) on the crib-sheet: mix and idle, before Progression – that's OK, good practice, and a much better understanding of what's happening and why as I do more and think about stuff a bit deeper.
Temps (simpler this time; just the basics; there are variations for hills and wind for all of these, but trying to explain it all doesn't make the numbers clearer.) Progression chop speed (I'm using 30kph in 3rd) – ± 93-8ºC Cruising at 70kph in 4th – ± 115-120ºC Long WOT in 3rd to longer WOT in 4th and hold – 135ºC Highest recorded temp – 138ºC (I didn't see this; I guess it's after I throttled off from WOT – it rises for a few seconds). Pulling choke at slow cruise – nothing.
Plug, not so impressive – 25km, varied riding, not a chop: (and a bit confusing to me; black and some oil on electrode and rim, but not much colour on cone. I'm just going to do one photo, but I'll keep the plug in case more study is required:
Early? Ive never known someone to be so keen!! So where are we now? By the time ive caught up and wqnt to give my tuppence worth youve already got the answers, i think! (And you're dead right Si, you really should keep an eye on what i say, im easily distracted and then loose the plot)!! The points i remember are , checking fuel flow from tap....not easy. Just by lifting the end of the fuel line up or down an inch will affect the flow. And it can appear as a dribble when its actually flowing ok. Float bowl tops. Yes all the same/interchangeable between si 20/24/26.. With the 5.2mm cosa top having a larger supply hole (although there have been upgrades over the years). If youre getting lean results with what ever MJ you're running then i truely believe just by drilling out the float bowl supply hole to 2mm will richen things up, so do take that into account.
Fast flow taps...helps over come fuel starvation when riding at long WOT on tuned motors. If youve not bought the oversized jets buy a set from whoever, theyre all as bad as each other - poorly made (unlike Dellortos super fine finishing)! But at least they will be consistant if you stick to the same brand. BGM brand seems to work out cheaper from SCK. Also the markings on the SIP ones will eventually dissapear, unlike all the others. And theyre not ce n cheap too. SCK flat rate post €5
Al, are you running a 150mj on a 200? I think i remember asking that before now!?!
Ive probably missed most of the useful, important stuff but i wrote this out once alredy, posted it, then noticed the network was down (im still on the train) and lost it all!
Its too early i know but I had all sorts of problems with 2 x BGM fast flow taps due to , i believe, there being no breather pipe, causing an air lock. SIP taps have a seal washer issue, which when replaced goes away! Well see how good my SIP is when i get back from me hols.
I also forgot about the debate of ambient temps affecting cht readings...i just remember that the cooler the temps outside, the cooler my cht readings are.
The 52/140 is leaner yes but an earlier mixer could be used? And i didnt rrealise it was after the progress period. Oops!
Matt Cooper at Dellorto/Eurocarbs is the guy ive always had a good response from.
The si26 i had was actually only 25mm!
I also had a masdebate in my mind about tje si24 flowing faster,(because its smaller) than a si26. Cant remember the outcome as im getting distracted now.
Oh! Beware if or when you get your disc brakes,,, theyll be a bit sharper than discs. Dont worry, ive done the same, applied the front brake too much on some loose gravel and came to an embarrassing hault. Although that was on Diu island on a 50cc twisty i rented to explore. No damage done. Lesson learnt.
The Specials, such a class act in so many ways...Pearls Cafe used to be my ringtone for a while
Cant recall much more and another train station has arrived,,another 3 minutes to grab another chai Looking forward to seeing your range of biscuits
The early starts allow just a little deviation-time, H; but not too much.
We've got wanderings, musical wanderings, and Lord (or whatever Deity we're on this week) know's what else, going on all over the place here, so I'm just going to try to resist the end-of-term malarkey and give vespasco's earlier post the attention it deserves; I've broken it down to a few topics: 1) Fuel flow from tap: I've seen other posts (including your tests) elsewhere. It strikes me that I either want to test with the tap-to-banjo level as it is on the scooter, or as it is where quoted for reference to check against. I also want to test it with a full tank and a near-empty tank; that's my initial thoughts on the topic, but I have reading to do before I do anything, and I want to keep the scooter together, hopefully until after Christmas, but I'll probably get bored and tackle it before then. 2) Float bowl tops. Got a nice unmolested one off my old Dellorto, which I've dismantled and checked this afternoon, and will go on to my Spaco 26/26 to remove the possibility that my 2nd hand 26/26 Spaco had been tweaked; I don't think it had, but lets be sure. I'm going to do carb mods next (float bowl-to-MJ well, and possibly banjo-to-float bowl; you think both). I've got my eye out on Ebay.de for a 5.2mm Cosa one too, which I'll grab if I see one. I probably won't need it, but I have become a bit of a Vespa Magpie recently, so who cares!! 3) Fast flow taps; I'm expecting not to need this after I've done the carb mods. I recall that SIPs leaked, and that you fixed yours with a cheap little washer. I also thought the BGM were better, but I thought that was from you, which it obviously wasn't. As I say, don't think It'll matter to me for a while. 4) Oversized jets; I shouldn't need over 140 once the carb mods are done. If I do I've now got SCL142, 145, and 148, AND those rather splendid new ones out; the SS150 and 155! If I buy more, which I don't expect to need to, that BGM set has to be a winner. 5) I think you mean velocity in the stack of the 24/24 compared to the 26/26? - that's quite a subject to cogitate actually; the implications to jetting if that's correct. I'm curious, but wary of getting diverted into a confusing distraction – bet I have a ponder and a dubious theory or two though, now you've planted that seed. My initial thoughts are, if jet velocities are the same(?) and the jets are smaller for a 24/24, then the volume through carb is reduced if the 1:13 (pxguru gave a figure a few pages back for optimum efficient air-fuel ratio; that's numbers off the top of my head - I'd have to read back to check) is maintained. 6) Disc Brakes; I half-heartedly hoped they might have arrived today, but no joy today. I won't touch them for ages, but I'd quite like to have them here to have a look at before I put them away and forget them for a bit. There's bound to be scabby knees before I've got to grips with them! - I've been thinking about getting my new wheels and tyres scrubbed-in before it gets cold and icy too, but there's still a good bit of tread on the old ones, which will probably get filed in 'big-spares' never to be seen or used again once removed, so I'm hanging onto them for a bit longer. 7) Biscuits, MD, Drag Strip 0-60; gotta be patient. I would have had better figures when I was nearly seizing with the lean, splendid running around I've unwittingly been doing 'til now, but I think this overjetting has dampened it down a bit now. The plug I did this morning, is a bit dodgy as well. When I get this carb sorted and some proper jetting, we'll have to wait and see what biscuits and numbers I'm getting. Those white plugs were not to be ignored; I'm working on it, and I confidently predict that....................................................
Better mus(t) come:
couldn't resist another pun – not even sorry this time!! (good flimshow too).
I expect, by the time you read this, we'll all have moved on to carb drilling and flow measuring, except maybe the holidays here, and a planned, brief lull in proceedings, will give you a chance to keep up. That's it for now; not sure what I'll get done over the weekend. Reckon I'll clear the decks tomorrow, and do a bit sunday; there's a decent forecast here then.
Way too much joviality, there's serious not blowing scooter up business going on here
Plug is a bit too rich now! If you leave it a while it might blacken up. This is a bit over how it should be when the carb tuning started. No point in setting it up any better until all the carb mods are done. Good you have all the stuff already. When the other float/needle/top (all drilled out) and the main jet way at 2mm are done. And the tank fuel flow is tested ok. After this then start the jetting cycle again from the beginning.
For the tank test just run it into a bucket with the banjo on at carb height. For the problems you are seeing early in the rev range, any issue will be obvious.
Temperature is cooler, which is how it should be but now a bit too far. Don't take the temperature reading too seriously at this stage and get hung up on the exact numbers until you now what correct is for your set up. How the plug looks is the most important. Once the jetting is near correct the gauge is invaluable in selecting the jets that keep you in the zone. The plug colour is never wrong! Just have to know what it all means
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
Too rich will do nicely for now; I'll use it for a bit like this and see if the plug colours-up. If temps are safe enough as well, I can just keep my eye on the gauge too, rather than making it the main focus. You say too cool; going by how it felt, it had occurred to me to open up the SS150 a tad, but I'll probably just leave it all alone now. I should have mentioned that I dug out the old INC air corrector too, as you said; in amongst the other boys messing about, I was trying to concentrate and take it seriously, honest. Carb drilling next; I'll read it up and clarify before going ahead; now we have the scooter safe to ride, this will be what I'm concentrating on. I found flow rates in several places the other day; I'll find them again to compare. Carb-height would be the most accurate for actual in-situ flow, but I was going to try to check that's what the quoted flows did too, if they say. (Banjo on; noted). No need to make it more complicated than it needs to be though, if it's obviously OK or obviously not - other than to get some data for future while I'm doing it. That plug threw me a bit; going by how it felt, I had expected it to be darker, but it was quite wet too, and the temps were lower, so I thought it was either not a long enough run, or the short, slow ride back through the lanes and streets at the end probably left it like that. Anyway; I'm good to go, got a good plan, understand what we're up to, and will be ready to start this jetting again after the carb mods and flow tests. Happy days...........
**One last afterthought. I'd like to take my time with the carb, as an indoor job, done with a bit of precision and care; would it be too messy to put the 24/24 on, say with a 15%ish smaller MJ (127-130), so a) I'm not rushing the carb mods and b) for interest to see what jetting gives me a similar safe-rich ride - though I can see the time needed to get this accurate would probably be more than the time to get the carb mods done. - just a thought, anyway.....
Last Edit: Dec 19, 2015 5:30:16 GMT by sime66: **afterthought
Just been to the shops – dark, warm and wet and windy. Just to note; barely got above 100ºC, definitely a bit sluggish, and a couple of obvious splutters when opening it up; I guess this is how I should leave it for a while. (and how it should have been - noted for next time). No more tearing around thinking it's going to be a beast, and no more messing around on the forum.
Important news for vespasco though, if he's heading over that way:
All dogs have been banned from the Himalayas due to new poop-scoop regulations. So now dog-men don't climb... But cat-men do!!!!!!
Just for interest, my small drill bits and my bigger Mjs arrived today, so I used the drills to see how accurate the Jets are. I appreciate the drills might not be precision, but despite not even being branded with any manufacturer, they measured pretty well:
**So my SS150 was a bit under-sized; I have corrected this now, and might have another go with this slightly larger jet sometime. I'll also check the SS155 sometime too.
Drilling the jet by hand wasn't so out then! Close enough for sure. Those jets do look a bit rough but will work. When all the carb mods are done, other float top fitted, other 160 air corrector and the tank flow is checked ok, if it does still need end up needing something like a 150 MJ then it is actually a beast. If you ever decided to move the ports a bit and fit an expansion it would surely need a very big carb and some bicycle clips for you.
That's some amazing trip Vespasco is doing. I just imagine it must be like one of Michael Palin's adventures off the telly. I hope he travels some of it by scooter
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
I'd rather use one of my drilled ones than one of those I got yesterday! Beedspeed will palm you off with any old rubbish if you let them; it is regular practice for them and I've had enough of getting sent tat, and putting up with it because it's too much of a faff to return. I told them yesterday that they were selling tat as genuine (Beedspeed listing says “Spaco or Dellorto”***), and they said they'd sold loads of them and Dellorto didn't make them anyway (though Beedspeed still list as Dellorto), so I pointed out that their European competitors, and some of the more conscientious British competitors (e.g. Wasp) managed to trade without selling tat. When it got to the point where they reckoned they were doing me a favour by letting me queue in the Post Office a couple of days before Christmas to return for a refund, after I'd waited for them to send me the shoddy, mislisted parts, after they'd got them back, probably sometime next year after return post and banking delays, I told them to stuff it. I bought the BGM set 140-162 anyway (Scootercentre listing says “BGM PRO for Dellorto type 4576”***), and Beedspeed have dropped right out of my list of preferred suppliers. - That's my mini-rant over.......
I'll do these mods and see where it ends up. How it felt when it was too lean the last few weeks was really good to me; I could feel it in acceleration, on the hills, and top-speeds. I don't see me wanting much more of a beast than that; back to that will do nicely. Though after a year on it, who knows; especially if I do plan any sort of a proper adventure. What jetting it will be after the carb mods is a bit of a mystery to me at the moment. We've only got this approximate pre-carb-mod benchmark; the ss155 is known to be too rich, but its size needs checking; I think I'll do that today and try the now known ss150, which was too lean without the carb mods, but is a bit bigger now I've checked it. Wherever it ends up, I'll have to be careful not to be too close to danger to get it feeling like it was again; I can see how it's tempting to do that. As you said, the CHT will earn its keep at that stage, and I can get it just right with the plug - got to redo the Pilot first anyway. I suppose we're expecting between 140 & 150 after carb mods; we'll know soon enough – I have the full-range from one source now; BGM 140-162, rather than swapping between Dellorto, unknown tat, and my own skillfully-crafted, bespoke jets. - Actually, with that in mind, I might as well leave my jet in the scooter for now; it's only a couple of days, not worth messing about. It's rich and safe, and I'm not going far. I'm going to try to leave carb and tank alone for a few days though; read-up on the jobs, ask some questions, keep everything here clean and tidy now, and maybe tackle it next long-weekend. Palin used the train a lot too, at least Guy Martin bought a bike out there and rode about a bit - both good viewing. I'm sure vespasco will get the urge for two-wheels at some stage, but it is quite an adventure anyway.
***Only one of those listings is honest; I know where I'll be shopping in future - quicker and cheaper too.
Let's not end it on a sour note – Happy Sunday all!
So, I've got a long drill bit like it says, and a smaller one to start the hole off with; I've got my eye protection, and some first aid stuff ready in case of accidents........
I had twigged ..but seriously your attention to detail and througness (i cant spell that, but you know what i mean ) i am in awe of..when mine gets too the point of actually being ridden i,ll be reading..then re reading all of this thread again...then i,ll be asking you too explain in simpler terms to me as lots of it goes over my head..if mine needs fettling when its up on its feet i may just print this whole thread off...give it too my mechanic mate at is shop and tell him too work his/your/pxguru,s/vespaco,s/Henri,s and everyone else thats contributed to this build threads magic
When we mess about, I do think about others trying to read it, but it is Christmas, and my year-long (from drawing board to road - if you like) build has reached a bit of a milestone now with on-the-road carb tweaks, so a little lightheartedness is OK. In fact, when I was trying to read back, just the last few weeks to get my dates, temps and stuff in one place when we had the heat-scare, it is clear that a thread of this length does get a bit cumbersome when you're looking for something specific, but I don't know how we might do it better.
I use PDFmyURL to get it all as one document, which, when it's done, I'll put on a disc with the other one as one complete build document:
I've been having a read of vespasco's thread, and comparing his notes with my old Dellorto float chamber top; there's quite a lot of info in there, which is much more relevant to my own setting-up now than it was when it was written, but his words of caution and some disagreement with other contributor's have left me a little wary, so, although I'll go into all that in more detail later, for now I was hoping to clarify what I can/should safely do with my carb. I think I have four areas to work on: A) This hole allows filtered fuel down into the needle valve, the chamfer I'm doing is to keep the top of the channel clear of the filter lid. The bigger hole is just where the bolt goes, so it's just a case of opening it up with a chamfer to clear the lid, but keeping away from the threads. - no harm done. B) This hole allows unfiltered fuel from banjo into the chamber under the filter; on mine it does seem to be open full-width, but needs clearing of swarf/rough casting; I'll get a needle file up it, and clear it all out to the same size across the full width. The narrow point there seems to be where that channel opens into the chamber where you can't really get to it anyway; I'll clean it up and make sure I've left no swarf. C) On the write-up this is stated as ø2.3mm; mines actually less than ø2mm, and I'm opening the channel from float bowl chamber to MJ well to ø2mm, so I will open this to ø2mm as well., keep clear of the valve seal, and leave it free of swarf. D) (not shown) This is the channel in the bottom of the float bowl chamber, which supplies the MJ well. I am going to open this up to ø2mm, and make sure I leave it clear of any swarf. I'm going to make sure I understand what else vespasco was doing when he did these carb mods (I'll especially try to get a better understanding of the mixers, which I'm aware of, but haven't really concentrated on yet), but what I want to do first is to make sure I have these four little jobs right in my mind, and that we are all agreed that they won't do any harm. It isn't the end of the World if I bugger up a float valve top, but for the sake of clarifying with a quick sketch and a post, and waiting a while for confirmation, I might as well ask the question before doing irreversible work. Basically I'm just opening to 2mm all the way, and clearing a couple of bottle-necks, so it should be easy enough and not causing any problems. If I do this top first, I shouldn't need to have the carb off for more than a few hours or overnight to do D). - Then I'll do the tank flow too, and back to business with the jetting.
........Actually A), B), & C) were pretty obvious; with A) there has to be a little ledge for the filter to sit on/seal against the casting, B) is just opened and cleaned-up afterwards, and C) actually was nearly ø2mm already; just a bit manked-up, so the drill went right through both holes after very little work, so that's done, but not much change at all. So I think it's just D) to do, and for that I need the carb out. Here's a quick update photo:
That carb top will no longer be the issue for sure. Holes plenty big enough Hows it look up from the needle seat? Is the carb out to get D sorted yet? The other thing to check is hole E. This is the overflow/breather hole at the back of the carb body. No need to drill it out but be sure that it is clear. Will soon be back to the real job.
PX200E with 221 Malossi, max power at 8300rpm, VHSH30CS, 175 main jet PX200E Tourer, tuned original barrel, SIP road II, SI26/26 135 main jet, vortex 1050cc Triumph ST 600cc Honda CBR
That job was fairly straight forward; will be proceeding with caution on D) and checking E) - probably early this week, so I can get it back together for holidays, but I'll see how the next few days go. I'll do the tank flow tests then too. I imagine/hope I'll be back to a rich/spluttery/black plug test ride after that, and wanting to swap down if it is (148 ish to start?), in which case it would be good to start with the new BGM 140-162 complete set to save switching between different makes and qualities as I tweak; they should be here this week, but that's not certain given the time of year. I'm also going to have a dry-run on a carb body to make sure my drill is going to be long enough to get the angle I need; if it isn't I've caused myself a delay there, but in any case - back to the proper-job soon enough..................
**Edit - was a bit bleary-eyed before; had a 5AM lie-in! You asked about the needle seating; It is good; this is off a carb I used for a long time with no fuel shut-off problems, I've cleared it of any swarf I may have caused and I'm going to use a brand new needle valve, so no worries at all - bit tricky to photograh, but I'm happy with it. I should add that I've checked the I.D. of that brass tube; it's bigger than my ø2mm drill, but I did not wiggle it about, just slipped it down from the top to see if it would pass through - bit wary of the valve seating there to do more than that. It's very tidy in there; clean, flat and smooth on the valve seat; those couple of bright spots in the image ar ejust where the light's caught the shiny edge of the opened holes - I've checked very carefully in there:
I've done a dry run on an old carb this morning, to get ø2mm through from float chamber to MJ well; it seems OK to go ahead with that with care on the 26/26 – it's petty clear when you've broken through into the well, and reaming the hole and blowing swarf out in both directions did clear a good bit of swarf out. What concerns me a little though is that there must be a bit of a potential for swarf to be sitting in the bottom of the well now, under where the MJ seats, in a bit of a dirt pocket, where it could be drawn up and block the MJ. I've done a scrap-section through my carb drawing, (that I'd started for the animation), to show where I mean; I don't think I can do any more than thoroughly flush it in all directions at all angles, but has anyone else thought about this, worried about it, had problems with it etc.? Here's a little sketch; your not actually drilling into the bottom of the stack, but into a chamber under where the stack narrows to seat the jet:
Ive been reading with interest and have also invested in getting the carb right.
im Running a Polini177 matched/ported
cut crank
open rotary pad
22 tooth primary upgear
DRT modified Si24e standard filter holes drilled
Sip No4 throttle slide
NGK br9hs plug
JL RZ Righty
I recently purchased the DRT modified Si24e carb from Sip because I couldn't get proper fuelling above an indicated 100km/h
My plug was always white and ashy anytime I was riding at speed on the freeway.
After fitting the carb with the same jetting I was using in the standard 24e (160/be3/140 48/160idle jet)
it was instantly rich everywhere in the throttle range 4 stroking around town. But as soon as I jumped on the freeway it had fantastic top end and easily pushed through and beyond 115km/h easily dropping back to an indicated 110km/h cruise. Its finally nice to have some color on the plug.
To clean up my low speed in town running I went from a 160 to a 190ac kept the be3, upped the main to a 142 and dropped the idle from a 48/160 to a 45/160.
It still 4 strokes a little around town on light throttle. my mixture screw is approx. 1 1/4 turns out from fully seated.
I never thought I had fuel starvation but now im convinced. Don't hesitate to do these mods, but be prepared do rejet the carb afterwards
Malossi166 ported matched Serie Pro flowed reed valve crank 57mm Malossi 30mm phbh carb/reed valve manifold kit Opened intake to match Malossi manifold Ngk BR9ES Flywheel milled down to 1.6kg Sip cnc ultrastrong clutch with L reinforced springs and updated circlip readspeed unlimited cdi 3 degrees retard Sip performance left hand 22 tooth primary up gear and larger 100/90/10 rear tyre