1968 Honda Trail 90 recently stabled

[Flying Wrenches]

I am wondering the fitment of engines from Honda for the trail 90 I have captured recently. Lots of Kroil oil and wedges have release the piston finally and I am seeking either a head or head rebored or just deglazed since it is not nicked. But I noticed a huge cost difference in C90 kits and CL90 kits. Will a C90 engine fit my frame?

[PeterT]

Welcome to the board Sorry for the slow reply ..... everyone is out enjoying the sun I guess.

I'd say no. The 85cc engine won't fit. Or it would but you'd have to embark on some serious conversion.

[Capitano]

There are folks on the forum that know far better than me, but I suspect it would be similar to fitting a 12V 85cc C90 motor in a 6V C90 rolling chassis.

eg. A bit of a PITA but achievable if you really want to.

[nabs]

I'd assumed that the 6v C90 engines would be a direct swap on the 1968 model, since according to the parts manuals they basically share the same engine (including the 3 speed gear box for the k0 models, I think?).

The engine hanger bolts on my 1969 CT (which has the high/low "posi torque" gears) and my 1978 C90 are in the same position and I am pretty sure they could be swapped. I haven't tried it though and it would be better to wait for someone to confirm for sure before spending any money.

Incidentally, if it is only the cylinder/piston that is damaged you can still get genuine oversize pistons/rings for the 6v engines.

Not sure where you are based, but in the UK 6v engine parts are getting harder to find (and are expensive) - if you are not bothered about originality it might be easier/cheaper to look at the adapter kits that let you fit a chinese engine.