FreeWheel Posted March 27, 2018 Report Share Posted March 27, 2018 I will be changing the exhaust and airbox in the fullness of time. But start with I will check over the original carb for signs of wear and replace the O-ring that is around the main jet (this caused problems on another bike a few years back). The reasoning behind the move to flat slide is that I have one on a motogori tl320 which replaced a delloto which was in excellent condition it just seems to make it run better and smoother. 1 Quote Link to comment Share on other sites More sharing options...
FreeWheel Posted April 2, 2018 Report Share Posted April 2, 2018 (edited) Upton servicing the existing vm22/ss mikuni. I found the needle clip retainer (round piece with hole and slot in) missing from the top of the slide. Anyone now were to get one from. Has anyone tried a newer mikuni vm series if so what jets and what size did you use. Do the base setting from the original work as mine is jetted the same as the ty175 manual with the exception of a 20 pilot jet instead of a 25. Edited April 2, 2018 by FreeWheel Quote Link to comment Share on other sites More sharing options...
tony27 Posted April 3, 2018 Report Share Posted April 3, 2018 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 Quote Link to comment Share on other sites More sharing options...
feetupfun Posted April 3, 2018 Report Share Posted April 3, 2018 22 hours ago, FreeWheel said: Upton servicing the existing vm22/ss mikuni. I found the needle clip retainer (round piece with hole and slot in) missing from the top of the slide. Anyone now were to get one from. Has anyone tried a newer mikuni vm series if so what jets and what size did you use. Do the base setting from the original work as mine is jetted the same as the ty175 manual with the exception of a 20 pilot jet instead of a 25. You can buy that clip from bearing shops Quote Link to comment Share on other sites More sharing options...
feetupfun Posted April 3, 2018 Report Share Posted April 3, 2018 22 hours ago, FreeWheel said: Upton servicing the existing vm22/ss mikuni. I found the needle clip retainer (round piece with hole and slot in) missing from the top of the slide. Anyone now were to get one from. Has anyone tried a newer mikuni vm series if so what jets and what size did you use. Do the base setting from the original work as mine is jetted the same as the ty175 manual with the exception of a 20 pilot jet instead of a 25. I don't think that a carby like the standard TY175 carby is available new from Mikuni. I think they do a 22mm carby but it is flange mount so you would need to machine off the flange and fit an inlet spigot. Quote Link to comment Share on other sites More sharing options...
goudrons Posted April 3, 2018 Report Share Posted April 3, 2018 Feetupfun is correct, the standard VM22 has a flange, unlike the original SS with a spigot. The original VM22SS carb was some sort of special, one off jobby, even Mikuni know very little about it, I tried to find a new one myself a few years ago, but ended up doing the swap to a stock VM22 that was machined to fit. BJ Racing can supply a stock VM22 which has been machined to replace the SS as a kit. If I remember correctly, SS takes a very large main jet (240 rings a bell), the one in the machined stock was about half that, methinks. You might find a OKO kit for it at Mid Atlantic Trials or you could have a go at jetting one yourself. Though be careful if you do try this, even though the OKO is a copy (of a Keihin), there are ropey copies of the OKO's out there these days and none of the proper OKO's jet will fit. As you have probably read, a lot describe carb set up as being fussy or difficult, but what tends to happen is owners end up chasing a "better" set up. There's always a danger of tinkering and fiddling to see if you can make it better! 1 Quote Link to comment Share on other sites More sharing options...
FreeWheel Posted May 15, 2018 Report Share Posted May 15, 2018 What sprockets sizes is any using for trails work either 428 or 520 chain mine is 12 gearbox 52 rear wheel any got any thoughts whether 520 chain is a better way to go as well than 428. Quote Link to comment Share on other sites More sharing options...
turbofurball Posted May 16, 2018 Report Share Posted May 16, 2018 I've got a 428 chain (lighter, plenty strong enough for a 175) and standard sprockets ... if I were to make a change, I'd want to try 1 tooth up on the front so 1st gear is more useful ... though that may then lead to having to change gear in some sections that I could otherwise have done all in 2nd ... Quote Link to comment Share on other sites More sharing options...
feetupfun Posted May 16, 2018 Report Share Posted May 16, 2018 12 52 is good for trials competition use with a standard motor. 428 chain is good. Quote Link to comment Share on other sites More sharing options...
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