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Post by sime66 on Aug 25, 2015 19:33:24 GMT
Yes, piston rings. It's not such a tricky job; no dropping or splitting engine - reckon we could talk you through it if others agree it's a good idea and you feel like tackling it. There's a few recent threads on taking the barrel off in-situ; if you're interested I'll dig some up.............
(Everyone on here has asked these questions at some stage in the past; no question is stupid if you need the answer to enjoy your scoot).
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Post by bignico2411 on Aug 25, 2015 19:56:16 GMT
Thanks, sime. I do feel like a bit of a mug asking all these questions, but I suppose if you don't ask, then you never learn anything!
I'm certainly keen to expand my knowledge and maintenance skills, so I'm happy to have a bash myself if the consensus is that it's a good idea. I should point out that I have no garage or access to a workshop, so I'm wholly at the mercy of the weather and my toolbox.
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Post by sime66 on Aug 25, 2015 20:17:21 GMT
I'll read your thread(s) and dig some stuff out in the morning. I take it you've done checking for air leaks, around head, carb, exhaust etc.? My warm starting thread is here (you might pick something up): vespa.proboards.com/thread/3194/px-poor-starting-when-warm& vespa.proboards.com/thread/3215/problemI'm only working in the garden and kitchen myself; you just have to plan it a bit to make sure you've got the tools and parts to get it done in one go, or leave it weatherproof. Basically, if you do it in-situ, you've got to drop the exhaust off the stub, take the head off, remove a couple of cylinder studs, withdraw the barrel, take the piston off, inspect barrel, head, mating faces, give it all a good clean-up (decoke?) and change the rings (if all else is OK). Then it's a bit of measuring, running-in and checking. (see the advice I got in my threads above). There's a few more technical threads; it's mainly getting the barrel clear of the frame that's tight, but I don't want to start looking for them now, and others have much more experience than me anyway. I'll see what they come up with and maybe spend a bit of time on it in the morning if anyone agrees it's worth doing.
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Post by bignico2411 on Aug 25, 2015 21:02:33 GMT
No, sime, all I've done to date is strip and clean the carb, replace the float needle and gaskets and fit a leaner idle jet (45/160). How would I check for air leaks?
Thanks for the links; I'm going to print off both those threads in work tomorrow as there's lots to highlight/ask questions about. Looking at what needs to be done re piston rings, it doesn't seem too daunting a task (famous last words!), though I'm sure I'll have further questions on the actual process. I have a new plug on the way (B6), so whilst the bigger job is discussed/planned, I'll lash it in and see if it makes any difference, even in the short term.
I really appreciate it you taking the time to look into this, thanks mate!
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Post by sime66 on Aug 26, 2015 7:35:54 GMT
I've had a quick read back over it; you've already got the clever chaps helping you with carb, so first job is to finish that avenue of enquiry. Then, when you've read the links, and hopefully they've chipped in again (I've only learnt from them as well as you'll see from reading it), we can get an order of stuff to work through; I thought you'd already looked at other stuff too, so I was probably premature with diving in with rings – there's simpler, cheaper possibilities to check first. Probably start with air leaks (carb, head etc.); making sure surfaces are flat, gaskets are good/replaced, and stuff is torqued down correctly and evenly. I see that Bryno did mention compression a while back – leaks, wear, rings, but otherwise it's mainly been about carb/fuel so far; best to get that right before moving on.
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Post by bignico2411 on Aug 26, 2015 8:25:15 GMT
I like the idea of working from the simple to the more complicated!! How exactly do I check for air leaks?
You mention ensuring surfaces are flat; I did check the carb when I had it out on a mirror, and it sat flush. I also replaced the gaskets in the carb. Similar check/replacement with head (I presume you mean cyclinder head)? If memory serves, torque settings are listed in Haynes manual, so checking them should be simple enough. If the weather holds up, I'll do that this evening and report back.
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Post by henri on Aug 26, 2015 9:10:56 GMT
to follow simes lead maybe youve a mate/friendly mechanic with more experience ,ride scoot to him an ask him to kick it over ,see what he reckons on compression , an every scoots different when worn , some want a twist off throttle as ya kick ,some wont start if ya touch throttle at all, an every position inbetween , if ya take it for a run tonight an it wont start have a plug spanner n check wetness/dryness of plug , will give a clue on wethers its flooding/lean mix-air leak . H
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Post by bignico2411 on Aug 26, 2015 9:16:51 GMT
H, when I last had the scooter at my local vespa garage, I mentioned the starting issue and the fact that there was at least an inch of 'play' in the kickstart before it 'bit'. He seemed to think this was normal. I'll take a pick of plug before and after a ride this evening and post up.
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Post by sime66 on Aug 26, 2015 10:14:13 GMT
As you're taking plug out and have camera handy, lets go just a tad further as a start: Take the plastic cylinder head cowling off and look for blows around cylinder head and barrel (look at my photos in those linked threads for clues of what to look for). I've re-read those threads myself this morning and the advice I got then answers a lot of your questions for checking/sorting leaks around barrel and head. Are you satisfied you did the carb gaskets (both?) and torquing correctly? Being loose around the exhaust can also be a problem – any of those leaks either messing up your air/fuel mix or your compression. After that, there's flywheel seal, and crank seal – but look at the barrel and head first – the simple, easy ones first. How old is the scoot? How long have you had it? How's it been maintained? How's it running generally? Have you changed/checked oil? (smelly – like petrol?) Can you bump it easily when it won't start? Are you getting a good spark when you kick it? - loads to work through, but I suggest you start with a look at barrel while you're out tonight – check stud nuts too, and post some photos of the bits we've covered so far. An experienced first-hand eye over it would help too; it's a bugger of a one to diagnose on the forum, not because of complexity of problem, but because there's loads of possibilities to work through; even if it proves to be something simple, which is likely.
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Post by bignico2411 on Aug 26, 2015 11:10:14 GMT
I'll do that tonight, weather permitting. Do I need to take the cylinder head off to check the barrel? I'm reading that back, and the answer seems intuitive, but I'll ask anyway! With regard to the carb, I followed to the letter the instructions on strip, clean and rebuild from a youtube video by an American guy (think I found the link on here), so I'm pretty confident it's ok. Scoot is 1984, and I've had her since 2010. It has been serviced every year since I had her but the guy who did it (scooter veteran, well respected locally) has quit, hence my need to be able to do some of this stuff myself. There is another guy I can go to, but his rep is hit and miss. Changing the oil was on my to-do list anyway, so I'll make a point of smelling it! As a side note, someone suggested keeping the old oil as a lubricant, good idea? I've never actually tried bump starting it, as any 'failures' have generally been at home and I've just said 'f**k you' and used the car! From cold, she starts third or maybe fourth kick (no choke) and she's running fine, which just adds to the frustration. Perfectly usable, as long as I don't park up for petrol, chips, a fag etc! I appreciate that online diagnosis is tricky with so many variables, but I am grateful for your input and by a process of elimination, I'm sure we'll get there
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Post by sime66 on Aug 26, 2015 12:04:44 GMT
I really meant just getting a torch up between fins to look for obvious leaks first, but if you have weather/time/tools/inclination then it wouldn't hurt** to take the head off to have a look (maybe withdraw the barrel a tad and have a peek (photos) too, and then torque them down correctly, evenly, in sequence, a bit at a time – you can look method and torques up.
**If you do that be careful not to introduce any muck between mating surfaces though, or you'll make it worse. With the carb, I meant the gaskets to box and casings, rather than the internal carb gaskets; there's one between carb and carb box, and another between carb box and casings – clean, flat surfaces, new gaskets, proper, even torquing – that goes for both ends; carb and barrel.
I stayed with a mechanic for first year, then decided it was time to do it all myself; getting better advice here than from mechanic – funnily enough due to a similar thing keep coming back to me apparently 'fixed' only to still be a problem – it's tricky to pin down, but we'll sort it. I only keep oil for diagnosis/comparison, not re-use. Let it settle in a jam jar – rainbow on top or smell of petrol is bad news, some muck settling is normal. I used a magnet last time too; saw lots of metal in grey oil and decided it was time to split casings – but that's another story, after one of my first over-exuberant attempts at DIY.
You're still starting it with no choke after previous carb tweaks though? Maybe that job isn't finished yet; mines like that mid-summer though, so maybe OK.
Anyway; I'm out of time, so that's all you're getting this morning, lets see what you find tonight.........
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Post by bigd on Aug 26, 2015 12:59:55 GMT
Nico, try and pick up the Vespa Technics dvds, both the Maintenance and Engine Rebuild, great information and helps you get your head around the workings. Sausage is very easy to follow. The lads on here are a great help too.
Hopefully you'll get sorted mate.
D.
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Post by sime66 on Aug 26, 2015 13:54:32 GMT
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Post by bignico2411 on Aug 26, 2015 14:24:27 GMT
I actually ordered the running maintenance DVD off ebay last night!! I didn't go for the rebuild one, as I hadn't envisaged ever needing it, perhaps I should have?
Sime, BigD isn't that far away from me, tbh, but he's far enough for a scoot that is playing silly buggers!!
Re no choke for starting; as henri said earlier, every engine is different and there appears to be no hard and fast rule for kick-starting. Though I did notice on your thread that someone offered up a technique they claimed to be consistently successful. I'm going to try it tonight out of curiosity
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Post by swm on Aug 26, 2015 14:34:23 GMT
Hi bignico , don't want to confuse matters for you ! I know you've gotta standard set up so some stuff might not apply but some of the info below might help , I hope so. If not I'm sure a more responsible adult on here will put us both straight.
Quote - "When I stripped the carb, there was fuel in the float bowl. I put this down to the float needle being worn, but could the float itself need replacing?"
Fuel in the bowl - Normal, just fuel you haven't used before switching off. Worn float needle - When petrol enters the bowl the float will rise, lifting the needle to stop more fuel entering. If the tip of the needle is worn or damaged it wont seal off properly. So as said needs replacing. Turn carb upside down and blow hard through the banjo. If it stays sealed the needles ok. Replacing float - If your float doesn't float it wont lift the needle and stop the fuel ! Only way to check is to immerse in water and look for tiny bubbles.
Quote - "When the fuel tap is turned off, the scoot continues to run for about a minute. I don't know if this is excessive or normal"
Running time with tap off - Not excessive , normal. The engines just using up the fuel in the bowl. On mine I turn my tap off well before I stop riding and leave It running while I've got my helmet , gloves etc. off.
Quote - "The throttle twist grip does not snap back. Embarrassingly, I'd not noticed this before until a fellow scooterist mentioned checking it today. Doh!"
Snap back ! - Some do some don't ! I have two scoots with similar carbs (delly PHBH and PHBL) The Vespa PHBH snaps back. The Lam PHBL doesn't . Its my cruise control ! I've seen people fit springs inside Lam headsets but I'm used to it.
"Once the scooter does start, it runs fine, no stalling, misfiring , losing power etc. Idling is a little off, but a tweak will sort that." - Result !
Cheers.
P.S. Apologies for terrible typos , piston broke !
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Post by bignico2411 on Aug 26, 2015 14:39:57 GMT
Hi bignico , don't want to confuse matters for you ! I know you've gotta standard set up so some stuff might not apply but some of the info below might help , I hope so. If not I'm sure a more responsible adult on here will put us both straight.
Quote - "When I stripped the carb, there was fuel in the float bowl. I put this down to the float needle being worn, but could the float itself need replacing?"
Fuel in the bowl - Normal, just fuel you haven't used before switching off. Worn float needle - When petrol enters the bowl the float will rise, lifting the needle to stop more fuel entering. If the tip of the needle is worn or damaged it wont seal off properly. So as said needs replacing. Turn carb upside down and blow hard through the banjo. If it stays sealed the needles ok. Replacing float - If your float doesn't float it wont lift the needle and stop the fuel ! Only way to check is to immerse in water and look for tiny bubbles.
Quote - "When the fuel tap is turned off, the scoot continues to run for about a minute. I don't know if this is excessive or normal"
Running time with tap off - Not excessive , normal. The engines just using up the fuel in the bowl. On mine I turn my tap off well before I stop riding and leave It running while I've got my helmet , gloves etc. off.
Quote - "The throttle twist grip does not snap back. Embarrassingly, I'd not noticed this before until a fellow scooterist mentioned checking it today. Doh!"
Snap back ! - Some do some don't ! I have two scoots with similar carbs (delly PHBH and PHBL) The Vespa PHBH snaps back. The Lam PHBL doesn't . Its my cruise control ! I've seen people fit springs inside Lam headsets but I'm used to it.
"Once the scooter does start, it runs fine, no stalling, misfiring , losing power etc. Idling is a little off, but a tweak will sort that." - Result !
Cheers.
Thanks for your input, swm, every little helps!! I replaced the float needle when I stripped the carb, so I'm pretty sure it's ok, but I'll do the blow test anyway. I'll also check the float itself. I'm reassured that the 'tap off' running time isn't excessive, and that not all throttles snap back. I'm going to lubricate the cable anyway, can't do any harm! Thanks again
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Post by bigd on Aug 26, 2015 14:46:24 GMT
Close yes but I'm still learning the in's and out's Si, my knowledge is quite limited, lol
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Post by sime66 on Aug 26, 2015 14:57:32 GMT
You'll both be on top of it in no time if you stick at it - you're sorting out others now BigD. - My knowledge is limited too.
Nico, The running maintenance DVD is pretty basic, bet you end up getting the other one as well. These two below are a good start, to give you an idea, until you do buy the other Sausage DVD:
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Post by bignico2411 on Aug 26, 2015 18:47:25 GMT
Ok, the weather was good to me for a little while when I got home, so managed a little tinker Spark plug cold Cylinder head. There was a large black cloud hovering, so I didn't chance taking the head off Spark plug after running for about 10 minutes. To my untrained eye, it looked the same Interestingly, the starting technique described in sime66's starting problem thread worked. Cold, it was full choke, no throttle, fired third kick. Warm, it was no choke but WOT, a few kicks and she fired up again and idled nicely
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Post by sime66 on Aug 26, 2015 21:08:41 GMT
Plugs don't tell me much; looks OK; not lean and not soaked when warm, which is where Henri's checks were leading I think. It's probably just a different make of plug, but there is a gasket on the plug under the muck and oil isn't there? it looks a little different to mine, which is flat for sealing onto head. Other photos neither - except it hasn't seen a spanner in a while. Did you do any of the other stuff?
(With mine, method of starting varies through the year - Summer at present; from cold: full choke, but back in immediately and a blip of throttle after firing up (1st or 2nd kick). From warm: just point my toe at it and it starts (half-a-kick). In Winter I have to run it on choke for a bit before pushing it in and keep the revs up 'til then). I turn my fuel off just as I'm parking up; just a habit I've got into after my starting aggro before.
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Post by henri on Aug 27, 2015 7:54:27 GMT
mine from cold ,tip to right for 10secs ,havent got a choke cable an this floods it ,kick twice no throttle an it starts , when hot kick once no throttle an if it dont start tip right 5 secs an kick again , any throttle an it wont start or will die til its warmed 15-20secs , an yes i was expecting to see a blacker/wetter plug ,but it looks ok for now ,if a tad on the lean side its hard to gauge by photo's ,1 thing is the colour ring on thread suggests its a long reach plug .as they must be stuck into combustion chamber to get colour on em , vespas run short reach plugs ,a long reach will work but get overheated ,might be ya poor hot startings down to that , H
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Post by bignico2411 on Aug 27, 2015 9:35:41 GMT
Si, I don't think there is a gasket, to be honest. There was rain on the way, mate, so I didn't have time to do anything else. I was surprised by just how much dirt and oily muck there was around the bits of the engine I could see when I took the cowling off. I'm starting to think my mechanic had been charging me for doing very little Would it be worth taking into it with something like this and then giving it a good spray of WD40? I've also gotten into the habit of turning my fuel tap off and letting the engine burn off the fuel whilst I'm taking my helmet and gloves off etc
H, 3 different scoots, and 3 different starting techniques that work, the wonderful world of the vespa!! With regard to the plug, I've just bought an NGK B6HS which was recommended in the Haynes manual, so I presume it's a short reach(?)
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Post by sime66 on Aug 27, 2015 10:40:37 GMT
I wouldn't worry about that comment last night, I thought about deleting it; I was looking for possible problems, so might have found a problem that isn't really there; it looks different to what I'm used to seeing, but I always get NGK. Anyway, you're getting the right plug for a bog standard px125, so the long-reach and gasket question will be sorted by that. Just for interest, the bit I'm talking about is in this photo below; it comes with the plug and you'd have to deliberately remove it, and I can't imagine anyone would do that, so on reflection I doubt it's missing on yours, just looks different and covered in oil and compost. I'm fairly sure I don't have oil outside my plug on top of the head though, which is why I mentioned it. Mine gets filfed-up around the lanes here too; mainly cowsh↑t though. On that subject, if you do decide to loosen and re-tourque those stud nuts, you'll have to clean them up and splash a bit of WD40 about anyway, and if you do take the head or barrel off, even just enough to have a quick look for leaks (like my photos in other thread), you must be very careful not to get any muck between the mating surfaces when you torque it back down, so yes a bit of a clean-up of the outside before opening it up has got to be sensible. I'd just clean-up and put that old plug back in and take a stiff, soapy brush to it all (after inspection/photos of head and barrel**). You can see the state of my engine when I first started looking at it myself from the photos above - around the carb – you don't want that muck getting in, so clean it up before opening it up, I'd say. Once you've sorted this warm starting problem, you'll soon get used to the foibles of your own engine, and know what works for yours; H said before that they're all a bit different. I don't think you need to habitually let it run dry until stops by the way. **If you do more later, try to inspect and get some photos of the barrel and head, where barrel meets casings, and head meets barrel, and compare with the obvious leaks visible on my fins on the other thread; do that before opening it up – you might be able to leave that job for the time being........ I'm getting back in the mood myself now, after a bit of a summer break from the dirty hands, and this morning I've been watching Sausage remove bearings, and then done my own; now I've got to fit the new ones, so I'll soon be getting back into my other engine build. - Treat yourself to the other DVD sometime; you'll soon be on top of this stuff and wanting to do more.
“Up to your nuts in Vespa guts” - as I believe you said.
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Post by bignico2411 on Aug 27, 2015 13:25:36 GMT
Si, just picked up the new plug and it does have the gasket fitted, so I'm guessing the old one does but is hidden by grime! I must admit that the oil on top of the head where the plug goes in alarmed me a little. I'll clean it off and fit the new plug then check at regular intervals to see if it reappears.
The forecast is utter dogsh*t here for the next few days, so I don't know how much I'm going to be able to do, but point duly noted re ensuring the mating surfaces are clean (I'd highlighted that in your thread). If memory serves, it was suggested that the mating surfaces be polished before re-assembly, what should I use if I get that far? I suspect all I'll manage this weekend is an oil change, cable lube and maybe a general clean up, but I'm going to start buying in useful products to have about the place. Especially now that I'm going to be 'up to my nuts in Vespa guts'.....
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Post by henri on Aug 27, 2015 18:26:24 GMT
god ,nuts|&guts here 2 ,sounds like a barbie at mine ,or is that nuts n sluts , some plugs do come with a convex seat n no crush-washer/seal, put the ngk in , HS means short reach ,the right plug for ya scoot , mating surfaces dont need to be "polished" just properly cleaned ,hunt down back of sofa n find a old 2p or really old penny ,there copper alloy n wont hurt ali cases as ya scrape old gaskets off , modern 1's arent copper an can be too hard . old goo n gaskets can be softened with wd40 or brake cleaner , the polishing referred to was i think if you find a head leak ,its actually called lapping ,figure of 8's on medium grit paper taped to a flat glass plate til surface is uniform n matt , otherwise its just a way of saying if you wouldnt eat ya dinner off it ,it aint clean enuff , all this talk of unrecognisable animal parts makin me hungry ,sausage sarnie i reckon , arseoles n eyelids ,yummie ,H
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Post by vespasco on Aug 27, 2015 19:44:33 GMT
Without ruling out everything else thats been mentioned so far, and scanning through the posts....
Something else id check is your throttle cable and carb slide - does the slide actually slide freely? Ie, if you have the carb in your hands and tip it from end to end does the slide, er, slide?! all the way from open to closed? I mention this as some of your symptoms are leaning towards it being too rich, maybe flooding. It could be the throttle not closing properly, along with a leaking needle/float assembly, causing the flooding.
As mentioned, take a look at your plug when it wont start. Keep your plug spanner in your pocket.
With the right plug in you should see an improvement.
I think there is a sealing washer on that plug. And i have had to take mine off to fit a thicker brass washer to 'dial in the plug' on my modified P200 head, (which use long reach plugs btw) this was to get it at the right height and even angle?! when inside the combustion chamber.
If you can take a carb off and strip it then im sure you could manage taking off the head if you think it may need a clean.
But certainly check your carb slide is snapping back freely at the very least.
The float bowl will and should have fuel in it so dont worry about that. Its when the bowl is constantly filling without being able to shut off. Check all these things. Along with a clean up, inspection etc
If you change the oil do drain a little out at a time and chack for signs/smell of petrol and also for any major debris (unlikely, dont worry)!
See how it is with the new plug first and if you manage to put some miles on post a piccy of the plug colour for comparison.
Let's hope for some BBQ weather for all of us B)
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Post by sime66 on Aug 27, 2015 21:50:33 GMT
Briefly, 'cos it's past my bedtime: This barrel/rings/leaks suggestion was intended to be after we are satisfied that the carb jobs are tackled, if vespasco thinks there's more to be done there, then it is wise to concentrate on those first, except for the plug, which is needed in any case. Don't forget that air leaks could be under carb or under carb box too, or even seals; the suggestion that you check the barrel for leaks applies equally to the carb. I don't think at this point you really need to be taking the head and barrel off, but an external inspection and retorquing of the head can be done without getting too involved there. Likewise, keeping mating surfaces clean if you do dissasemble is not the same as polishing, and in any case, as H said, we might get to the point of lapping if you have leaks, and might have to tidy up old sealant/gaskets etc if you disassemble, but you're not polishing stuff; just the figure of eight on wet-and-dry on glass to get flat and level (as you would have done with carb too if it had not been flat. if and when you get the barrel off later, we can go back to thinking about ring-wear as a possibility of the problem. If you're taking on the servicing yourself this year you want to be doing some routine stuff about this time of year, one of which would be inspecting/lubing/changing old cables, so that is an ideal time to check the throttle cable and slide. Likewise the oil change is wise anyway, and will tell us some other stuff about your engine when you've had a sniff of it and a poke about in the mud. Don't start tackling too many different bits at once, or starting work that might not be necessary; I repeat advice to finish playing with carb first, then visual inspection/torquing head/barrel, and spark plug, inspect and lube your cables and check your slide moves freely and closes properly, change your oil (warm engine btw) and have a look at old oil. That should be plenty to keep you going between the weekend deluges. You might even sort it and get a decent ride. If you're still having aggro warm-starting after that lot, we might want to look under the carb box, maybe; and then maybe onto barrel, leaks/lapping/rings, and then we'll think of more bits to play with...................... Right, I've done my new seals and bearings this evening; well happy with that – it's deckchair chucking time again!...................... (Seaside fish and chips, no barbie for me)
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al
1st Class Ticket
Posts: 50
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Post by al on Aug 28, 2015 7:16:51 GMT
I've had a similar problem to that but turning the fuel tap off and leaving it to stop has solved it.Starts first time now.
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Post by bignico2411 on Aug 28, 2015 9:23:36 GMT
vespasco, Si
Here's where I am/my plan:
Carb slide - checked when I stripped the carb, moves freely from one end to the other and snaps back nicely
Throttle - throttle twist grip doesn't snap back (according to swm, some do and some don't). Going to lube cable, see if it makes any difference.
Float needle was replaced when I stripped carb, but I'm going to do the banjo 'blow test' to make sure it stays sealed and check the float itself for leaks
Retorquing of head - is there a technique for this. I know it's equal torque and in sequence (opposites?) but is there more to it than that? I don't have a torque wrench, should I leave that job until I buy/borrow one?
Fit new plug
Change oil/inspect old stuff
General clean
Having seen the weekend's forecast, it'll be a minor miracle if I get all that done, but that's the plan. If I'm coming at it arse about tit, then please tell me!!
cheers
Nick
P.S you off to Brighton, Si?
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Post by henri on Aug 28, 2015 12:16:19 GMT
nope seems a fair plan of action to me , were are ya ,if close ive a torque wrench to play with . an doubt simes comin to blighty ,he lives in a far away place were the locals worship turnips ,cornwall , i'm goin but then i live in brighton so it would be rude not to go, H
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