I've just bought a TY80 and want to renew the gearbox oil but am unsure how to fill it to the correct level. The Haynes manual says to check the dip stick attached to the underside of oil filler cap but my cap has no dip stick (my TY80 parts catalogue also doesn't show a dip stick on the oil filler cap).

Please could anyone advise?

I am sure the capacity is stamped/cast into the engine housing somewhere near the kickstart as I remember.

550ml seems to ring a bell.Gear boxes rarely have dip sticks just put the correct ammount in.

Edited January 19, 200719 yr by PRW

Many thanks for your response PRW. I just thought Yamaha might have built in some level marker or an over-flow screw hole. It's just a problem at the moment as the bike has an oil leak so it's hard to keep an accurate check (without draining & refilling!!)

Not quite so tough as it seems. Once you find the right level, you just sort of remember visually which part of which gear should covered. Alternate: Put a mark on the outside of cover, then use a clean screwdriver as a dipstick.

If you can't find it cast into the cover near the kickstarter area, I can look it up. Might take a few days to find the manuals.

kcj

Many thanks KCJ for your response. The gearbox oil volume (500ml) is stamped on the casing.

The little TY80 is now running but I've been having a problem with the clutch slipping. Probably my fault as although the Haynes manual said 10/30 oil, I followed my local motorcycle dealer's suggestion to put in 10/40 as this would be better for the gearbox.

When I looked up 'clutch slip' in Haynes, it says high viscocity oil may cause clutch slip. I've now readjusted the cluch and it's working fine for my 8 year old but has anyone else found this to happen?

Would it be best to use 10/30? Thanks.

thicker oil may cause some drag when released, but should not cause slipping. May take some more time to lock up if there is too much oil in it, but once locked, should not slip.

make sure there is proper free play in the mechanism down below, nut just the cable.

Might also have had some springs removed to make it softer. I did that when kids were small.