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About cornishflyer

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    Sherco 250

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  1. Sherco 250 twistgrip

    Thanks everyone, looks like I need to become a better rider then.
  2. Sherco 250 twistgrip

    Sorry if this has been asked before, I did have a search. Did the 2007 Sherco 250 come with fast (white) or slow (black) throttle? Thanks
  3. Sherpa T 250 Conrod sideplay

    So, since doing the work to the crank I've been thinking that the crank I have must be from an earlier bully with two bearings on each side. The ridge visible must have been the line where the second bearing came up to. So now I'm worried that by taking off what ever metal I have I've put the shaft out of round, not to mention what ever else dimensions might be different with this crank. There is a friend of a friend that I will be able to take this to, hopefully I will be able to compare with the correct crank, and also check for run out on the shaft. I'll keep you posted.
  4. Sherpa T 250 Conrod sideplay

    Well I went at it with an oil stone and it soon appeared that I would need a lot more to get the sleeve onto the shaft, I ended up having to use a fine file. Hopefully, by working slowly and on the high spots I kept the thing round. I was careful not to touch the shaft under where the bearing fits. Next, to check the crank webs are still true, heaven knows what this engine has been through to cause these things
  5. Sherpa T 250 Conrod sideplay

    Great information, thanks, I'll proceed with your advice and report back.
  6. Sherpa T 250 Conrod sideplay

    Hi again, After many different attempts I finally got the seal "bobbin" off by cutting it off. I suspected to find some sort of adhesive under there but actually it's that the shaft seems to be too tight. The new bobbin is the same tightness, if I push it on the shaft I'm never going to get it off again. feetupfun, you said you find them to be a light push fit, have you ever seen them tighter? I'm thinking I'm going to have to get something machined, either the crank shaft or the inside of the bobbin. Cheers,
  7. Sherpa fork springs

    Yeah I tried that but he insists that 500mm springs are what I need in this bike, even though it was solid as a rock All good now though, I shortened the new springs to 475mm and it feels a lot better. I will wait till I get the engine in and then set the sag properly, possibly by taking a little more off. Thanks everyone for your help.
  8. Sherpa fork springs

    Hi OTF, yes I have, they run lovely and smooth with just the old spring in there, no binding at all. I've got some video I'll try to post so you can see what I mean. No probs about the eggs by the way, I'm all about the most obvious that I've probably missed.
  9. Sherpa fork springs

    Oh and the selling that was in the bike was 150mm long, 59 coils, 3.7mm wire thickness. Different again. 🤨
  10. Sherpa fork springs

    I'm 82kg, what's that? Around 12 stone? The engine is out but I've factored that in (I reckon that's another 25kg tops) still it's WAY too stiff. I can barely compress it by jumping all my weight on the bars. I think I'll just shorten the springs to around 475 and adjust from there, like the idea of the grinder, I hadn't thought of that. The seller has assured me he's sold thousands of 500mm springs with no issues so I don't know what the difference is in my bike. Perhaps Aussie bikes where shorter, less gravity down here, I dunno.
  11. Sherpa fork springs

    Hi all, I have purchased some new fork springs for my #158 Sherpa T 250 which are just over 500mm long and are so stiff when I install them that I can hardly compress the front end. My bike only came with one spring so I can't compare compression but the one old spring I have is about 450mm (50mm shorter) and comes up to the top of the tube when I remove the top cap. These new ones stick right out and it's a real struggle to the get the top caps on. The reseller tells me these springs are correct for this bike and something else must be wrong with the fork. So, I took the fork apart and it all look ok, perhaps I have incorrect length damper rods. The top tubes are 550mm and the damping rod assembly is 100mm My old Sherpa had very plush forks, and I tried another over the weekend that was also plush. This thing is rock hard with these springs in. Any help appreciated, especially the length of the springs I need. Thanks
  12. Sherpa T 250 Conrod sideplay

    I've just heard that around the time that this model came out the con rod was centered from the piston end using the small end spacers (which my bike has). Perhaps this isn't an issue at all (embarrassed).
  13. Sherpa T 250 Conrod sideplay

    No, not stepped, just that the rod will then stick out both ends of the cranks webs.
  14. Sherpa T 250 Conrod sideplay

    Quick update. I received my thrust washers today., they are each 0.5mm thick which is thinner than I was expecting because it's not going to solve this particilar issue. My conrod is 17mm wide, and there is 20mm between the crank webs so even after installing the thrust washers there is going to be 2mm axial play. This goes against what I have read on this forum and in the couple of general Bultaco books I have access to, all saying there should be around 0.25mm clearance. I can't see what is wrong at the moment. The big end pin won't allow the crank webs to close that side play down even more. Unfortunately I don't have anything else to measure up against. Could it be that the #158 sherpa did in fact have a lot more side play? Or perhaps that someone has installed the wrong size big end pin? Scratching head...
  15. Sherpa T 250 Conrod sideplay

    Quick update. I measured the play in the conrod and sideplay at the top is only 1mm. When pulling on the gudgeon pin I can't feel any play at all so I'm thinking the conrod might be quite new and is OK. What I would like to do is get some of the crank pin washers and just get the crank rebuilt. I'm not sure if I can get those without the conrod, or what the measurements/material is? I also can see on the exploded diagram that there is supposed to be a washer that goes on the end of the kick starter shaft (that fits into the RHS engine case. Mine is missing. Any ideas what that washer thickness is? Cheers, Dylan