Hi All, I picked up a 1980 Yamaha it175. The bike being 31 years old is five years older than I am. I am looking to use it for hare and hounds, classic events and even practice motocross. The bike on the surface looked tired but useable, realistically it needs a full restore, however I will only do the main items to get it race ready. Any good setup tips? Do other rear shocks fit and improve performance? I was looking at a set of yss gold valves for the forks, is this worth doing ? What do you all recommend?
Get new main seals get the rear shock serviced and spring the bike for your weight probably new fronk fork seals swing arm bushings/bearings check the wheel bearings. I am pretty sure I covered it all
shocktower has it right. the suspension in 1980 was an improvement over the earlier model, but they still didn't have it right. suspension is everything on this model. if you can make the rear shock work for you, it's a very competitive bike (although the it200 is light years ahead of it handling and motor wise) if it was mine, i'd find a 43mm front end from a 81-85 (can't remember exact years..) yz250/it or bigger and throw it on there. gold valves work well in the stock or in the 43mm front end. springing the front for your weight is crucial either way - most ITs are pretty under sprung (unless you weigh 140lbs..). once you get the front end worked out, i'd concentrate on making that rear shock work. - definitely check all swingarm bearing/bushing for wear. that motor is bulletproof.
I had a '78 model and used it to race desert. A lot needed to be done to the suspension in order to get it to work at higher speeds but mainly stiffer shock and fork springs. I had some re-valving work completed as well, and an increase in rear shock travel. BUT, the big thing was to change the swing arm. I had one of the first ProFab's for the IT175. What a BIG difference! Could not believe how much the stock swing arm flexed until getting this mod. :eek1 I also had quite a bit of porting done to the piston and barrel. It drank gas big time after that but it would haul ass. Super reliable and good bike even as a race only bike.
Thanks guys...what's required to change the front end? Complete front end including wheel? Or will it need stem/bearing mods?
Get a whole triple tree setup for the forks you are using. Yamaha was very consistant on the triple stem and you can either use the whole triple or press your stem out of your lower triple and put it in the newer lower triple (if it is longer/shorter). That should be about all you need to do. Stock bearings will work in either situation, but now would be a good time to upgrade to tapered rollers if you don't already have them (the YZ's did, but I have never played with an IT. Most of the DT's had ball bearings). Kenny
Any idea where I can pick up heavier fork springs? Yss do updated valves...will upgrade what I have and have the rear shock rebuilt to suit. What weight fork oil do you suggest and how much? I weigh 185
