Trials Australia Forums

Just bought a '76 TY175 for my boys (stepping up from the TLM50). The kickstart works, but does not engage until approx 2/3 through its stroke. This leaves only the last 1/3 of the rotation to use to turn the engine over. With the small displacement, etc it is not too much of a problem starting, but presumable it should engage sooner than that.

I have looked through previous posts and there appears to be a couple of common issues with TY175 kickstarts. Is this one a common problem and is it easily fixed? It would seem to me to be something like some teeth missing from the engagement gear, rather than the pressed on fitting or return spring coupling having turned on the shaft, but please correct me if I am wrong.

Obviously the best approach will be to open up the casing and have a look, but any advice or guidance would be much appreciated before I do so.

The normal TY175 engagement point is with the lever at 9 o'clock, which is about footpeg height on a standard bike. It makes the bike very kid and small person-friendly to kick start.
The reason it seems odd is that the mechanism was made for the DT175ABCD which has a kick lever that is stored in a more clockwise position, so when it engages the DT lever is at about 10 o'clock
There are a couple of common problems.
One is that the return stop on the shaft (inside the case) slips on the shaft, which can cause the kick lever boss clamp screw head to punch a hole in the casing. This stop can be welded or brazed to the shaft to stop it slipping. The stop can slip at any time from new.
Another is that the knuckle joint hole in the kick lever eventually elongates and then splits open. It takes many years of use for this to happen and new parts are available from Yamaha.
I've never seen damaged kickstart gears in a TY175 motor, and one of mine is an extremely high hours (trials use) motor which has gone through 3 or 4 kickstart levers from new. I've not had a kickstart shaft stop slip on me yet, but have seen many of them that have slipped, including one that the owner kept riding after a piece was punched out of the casing. The piece then found it's way between the primary drive gears, which broke and bent some teeth on the drive gears, and bent the gearbox shaft that the clutch runs on. That didn't stop the bike being ridden though, it just made weird noises. The piece of casing was still inside the casing when I first worked on the bike.

Thank you David. Extremely informative and helpful as ever!