tony27

Hi Jackman, I'll pass on a few little tips that will make your bike easier to look after etc Try & find 1 of the later short gear levers, when I bought mine it was referred to as the race lever but I think they became standard a few years later. The shorter lever makes taking the ignition cover off easier & is tucked in tighter to the motor. I also took the ignition cover with built in sprocket guard off & replaced it with a 06 or 07 cover without the guard, unfortunately the covers with the guard warp at the back so you need to keep removing them & using silicon sealer to help keep water & mud out of the magneto They are a very simple motor to rebuild, worst part is actually getting it out of the frame. Don't remove the head from the cylinder, you need to replace the o-rings if you do that & it;s not something that needs to happen The links pinned at the top of the Sherco page should have the downloadable manuals from Ryan Young Products site in the US, these are pretty good at explaining what to do including step by step photos so most people should be able to do a main bearing replacement in a day. When you replace your mains get the newer sealed type bearing & viton crank seals which do last longer, the viton seals are needed for modern gas with alcohol in it. I had the original tank grow enough that the rear guard didn't clip under the frame any more & it was a tight squeeze between the frame rails, I put that down to the ethanol in our fuel which guys have mentioned as a problem worldwide, I only run avgas in the new tank & haven't had problems since, as a bonus the fuel doesn't need to be used up in a month

From memory 10 on the front is standard & works well for me & is standard, I surprise people when they see what can be gotten up in first gear but still you second & third in sections often enough to know that it isn't overgeared Front changes the gearing more than the back does & saves buying a longer chain although depending on how new your's is you may need a half link for it to fit, Sherco around that era definitely had a half link fitted from new The 290s of that era aren't overly snappy, dropping to a 10 tooth will only put it back to how it was new

Looking at the front brake I'd say a 82 on YZ brake was used when 80/81 is what is really needed. The tab for holding the brake was moved 45deg which gives this problem

Don't cut the wires, should be able to trace where they connect & plug the lanyard switch into the same spots

Can't say I've seen that sort of damage to a trials bike impeller before. That's some nice work you've done with your replacement

I've managed to misplace the sprocket side axle spacer on my 250c & the bike is over an hour away so measuring the swingarm gap isn't going to be an option this week. Does anyone have their rear wheel out & can give me the sizing to turn up a new 1? Due to wear in the hub the bearing isn't the standard diameters but the width is the same as what came out, normally the spacer would stay in the wheel but I must have knocked it out at some stage

I see it's a Jarvis replica like mine, these were the last that they made. The tank & guard graphics aren't available anymore so I'd suggest getting rid of the rear bolts & running cable ties to allow the guard to unclip in the case of a step off. It was 1 of the first things I did when I got mine new & it has definitely saved me quite a bit of money

Can't say I've ever noticed much play on my 290, maybe pull the outside circlip & slide the sprocket out so it is over the part of the shaft that doesn't have the sprocket on it normally & see if the play is still there. I suspect there is something wrong with the sprocket rather than the shaft

I've read of a water & molasses mix being used in Australia for rust removal, as non toxic as you'll ever get but does take a bit of time. Have a look on the ozvmx forum & you should find a few different threads on this problem

Which of these parts are you meaning, the needle clip or what is called the spring guide? https://www.tytrials.co.uk/trailandtrialsuk/prod_935653-2325-Slide-Needle-Clip-Spring-Guide-TY125-TY175.html The needle clip is pretty common & should be available from Yamaha, the spring guide/seat is listed as NLA on Partzilla. Personally if you're doing a full carb rebuild I'd buy the full kit from TYTrials as your needle could be worn

That makes sense & would be the only true comparison When I get back in the country I will be stripping my forks to have bushes fitted to remove the play in them. Will be the perfect time to do damper rods & springs. I've been running a 17mm aluminium axle threaded into the base like modern forks for a while & I expect the springs & damper rods would make them as good as they can be without trying to stuff modern forks inside them

How would you rate them in comparison to the set with the emulators in David? I'm looking at fitting both the damper rods & springs into mine once Steve gives me a shipping price to New Zealand

The flatslides carburate better at low openings due to the slide being smooth on the bottom.

Quite possible for it to be the HT lead, 1 of the times I thought I had a dying stator it turned out to be a crack shorting directly to the head. My ignition is the same type & age Have you talked to the guys at splatshop, they'll be able to give you things to check

The rings that came with my TY piston are the same, goes behind the lower ring to help give more sealing pressure

No real club as such but a few riders from memory, get in contact with PeterB, he lives in Auckland & is the former gas gas importer

What part of the country are you in Willie?

Reading what Feetupfun has written I wouldn't bother about replacing the case if the shifting hasn't been affected & there aren't any leaks. Looking at Partzilla's listing the B & C model used the same cases which are unique to TY175s so I would say any TY175 case should be the same if you decide you really want to change cases

If it hasn't been leaking then you're probably safe to use as is Getting it welded should involve stripping the motor fully & takes some serious skill to do it properly without causing distortion. Not familiar with the 175 motor so I don't know about the steel cap, a photo would help to confirm that welding isn't needed

Pretty sure all Shercos come standard with the white throttle right from the beginning

From memory you would have been able to assemble the selector forks in the wrong position without having the gearbox locked in a gear Chances are something is wrong in the selector mechanism, if you can't see what put up a photo & someone may see what

I run the bike for a good 5 - 10 minutes up on a stand under the bashplate, when the fan has been on I run it up through the gears to fling any water out of the chain before oiling it then go through & do the normal maintenance Haven't had to replace bearings in quite a while

I would suspect Yamaha DT175 but not sure of exact model. 506 looks like pre80 model numbers

I was going to suggest www.claussstudios.com as they supplied the reproduction pipe for my TY250. Their eBay name is djia If you can find someone who is prepared to lend them the pipe off theirs then they will take a pattern off it & add them to their range

Guessing early 70s going off the shape of the CZ engine. I started trials on a CZ with the earlier egg shaped motor that I built a frame for, the motor was better than the villiers & bantam engines with more power & full circle crankshaft. Biggest issue was the charging system