trialsrfun

The piece you mention is part of the crank cush drive and is secured on a taper, do NOT lever it off it is very hard and will break up on the shoulder area, a puller is required to remove it safely. Steve Sell Marlimar OSSA is the person to contact for all things OSSA he has the puller. Steve Sell Marlimar 07800 788040 leave your name and number he will call you.

I fitted a Mikuni 26mm purchased from Motocarb to my TR77, tho other option might be a 26mm OKO but buy genuine from scooter assasins or mid atlantic trials then follow their set up guide.

Is that 25mm into the top tube but maintaining the same position where the down tubes meet the headstock. There is a lot of metal around that part of the frame in the toolbox area especially, where do you make the cuts? Thank you for your really helpful advice.

Thanks for the feedback feetupfun, the TY 250 forks are for the TY 175 project that I am helping a friend build. When you say a lengthened TY 175 I take it you mean extended swing arm, we are thinking of geetting the shedworks fork ends to do this mod. As yet we are undecided what to do with the steering head angle is it better to leave alone or steepen what are your thoughts please.

Has anyone tried Magical fork springs in their TY 250 34mm straight leg forks, same for the alloy damper kit which looks interesting but is rather pricey. Would like to know what difference these parts might bring.

Can only be buckled disc, sticking pads or caliper.

It is staying a 175, the other questions I will let him come here on tc and give that info himself, should he not then maybe we will make something up eh!!!

I fitted a 26mm OKO carb to my 250 Bultaco Sherpa model 124 to replace the oiginal 27mm Spanish made Amal concentric which was totally worn out. I carefully followed this tuning guide http://www.mid-atlantictrials.com/Instal.html and the bike now runs very smothly and cleanly all through the rev range, unsure if there is any more bottom end but it runs nicely which makes it easier to ride. As I understand it getting an OKO with the right choke diameter is critical then playing about to find the best pilot jet. There is a lot of OKO info on the weblink above and buy genuine not a copy from an auction site.

I am fairly sure that the clutch arm on a Mk4b was underneath the clutch case and both side csses were more rounded than those on the engine you have. Rest of the bike could be a 4b but the forks appear to be from the earlier model which had the big wheel hubs. If it runs and rides ok though you have a bike to trial and enjoy.

Am assisting with the rebuild of a TY 175 which when completed will be ridden in trials including the KIA series. What is the best set up for the frame and forks please, can the skinny leg 175 forks be made to work well, they operate smothly enough but seem very softly sprung with not much damping. The frame is totally standard what changes or improvements could be made to improve steering, handling, footrests etc or is it best left alone? Chain is 428 with 12t gearbox and 51t rear wheel sprockets fitted are these sizes a good choice, needs work before it can be ridden.

Hi Willy, As a 199a owner I think leaving your bike as is the better option, they are a great bike in standard condition. The only changes I have made to mine are slightly larger rear sprocket,26mm Mikuni carb and a todotrial bash plate which is wider than the original. Trials now seem to have more twists and turns than maybe they used to so the changes I have made suit this type of section.

Try this club...https://owdcodgersmcc.wordpress.com

https://www.pressreader.com/uk/classic-dirtbike/20170214/281659664780236

Best read the trials regs, rod or cable for brake operation in classic classes.

Your blue frame is the original 199a type the numbers on both blue frame and engine match. In my opinion the chrome frame is a SM aftermarket one. Personally I would keep the blue frame because of the matching numbers. Airbox is from an earlier model but not sure which one.

Does lightening the flywheel make the bike stall easier or reduce pulling power at low rpm ?

Madness to break that bike total greed. For linings try http://villiersservices.co.uk or a wheelbuilder who can replace the worn brake drum possibly with the rim attached try Paul http://www.yorksclassictrials.co.uk/classified-ads/4543674651

Thank you brucey

Can anyone tell me what is the correct ignition timing setting for a 199 cc Tiger Cub which has PVL ignition.

Which models of Bultaco Sherpa were fitted with a longer front pipe ?

Try Steve Goode for the bits you need.....https://stevegoodemotorcycles.weebly.com

I would still politely point out the above to the agent who may not know what a trial is. Also worth explaining that no one involved makes a profit from such an event..

Mod land is owned by the taxpayer why not remind them that trials riders are responsible taxpayers as well. With regard to the birds nesting a trial will do far less harm than shells, tanks and the like ripping through everything.

I think ND means the triangular type fitted to some of the 340's, this attaches to the existing head steady bracket but requires a second to be added. Does anyone have pictures of the second bracket which needs to be made and secured to the frame please ?

Are the frame weakspots just around the steering head or other places as well ?