There has never been workshop manuals for Fantic trials bikes. There is a parts list which shows exploded views of the whole bike, and there is the handbook that came with the bikes when new which has some specs for torques etc., both of these are attached to this post. The 240 is a fairly straightforward engine to work on, its the first one I ever rebuilt without a manual, and common sense should see you through it. It probably helps if you have built engines before and already have an idea of what goes where, just remember - if you are having to apply a lot of force to anything to get it to fit, something is probably not right. I have done lots of Fantic engines and am happy to answer any queries.
After pulling the RH case down with the case screws the crank bearings will feel tight - I use a tubular spacer on the inner race of the RH bearing and gently ease the inner race in using the flywheel nut until it feels free. I have tapped the inner race with a drift & hammer in the past but the spacer & nut works better.
I put the bearing in the case first, either heat the case up with a hot air gun or put it in the oven until the bearing will drop in easily, I usually put the bearing in a plastic bag in the freezer too.
I wouldn't recommend re using oil seals, the one behind the flywheel can be replaced fairly easily with the engine in situ but the left hand one can only be done by taking the crank out. Seals are available from Simply Bearings, get Viton seals for the crank, others can be nitrile.
Build it in the left hand case. Put all the bearings and LH seal in the cases first (heat cases to fit bearings), pull the crank in to the LH bearing using the primary drive nut and spacers, slot the gear clusters etc. in and then put the RH case on and pull it down evenly on to the crank with the case screws. Don't hit anything with a hammer, fit the RH seal last.
Pistons are the same as a 240 - not particularly cheap. 241 is a 1986 bike, as you say the frame and forks should be red, I think from memory Ford Rosso red is a good match. The tank would either be red with white decals or white with red & blue decals. I have got a parts list with exploded diagrams of the whole bike, but its a big file, if you pm me your email I can send it.
The tanks on these bikes were painted when new. I had a 301 about 15 years ago and re sprayed the tank and put on new decals with no issues. I would have thought that if you have problems with bubbling paint then it is probably caused by whatever paint has been put over the original (in the last 30 years). I would rub the tank down to the last layer of original paint and start from there.
It will fit but the spline on the clutch hub is different. You could use the clutch from the later engine too but you would also have to use the cover and the primary drive pinion would need a keyed bush to fit on the crank, I think.
Heating the fork legs helps a lot. Its a good idea to put alloy spacers in place of the lower fork seals - later Fantics came with only one seal per leg.
It wasn't overheating but the fan was wired to run constantly as the thermo-switch was not working. I just expected the vanes on the impeller to stick out more than this.
My daughter has been pestering me for a trials bike so I have bought her a Rev 50. I have taken the water pump apart and the impeller looks like it is worn away. Can anyone tell me if this is what a Rev 50 impeller should look like please?
240 engine rebuild
in Fantic
Posted
There has never been workshop manuals for Fantic trials bikes. There is a parts list which shows exploded views of the whole bike, and there is the handbook that came with the bikes when new which has some specs for torques etc., both of these are attached to this post. The 240 is a fairly straightforward engine to work on, its the first one I ever rebuilt without a manual, and common sense should see you through it. It probably helps if you have built engines before and already have an idea of what goes where, just remember - if you are having to apply a lot of force to anything to get it to fit, something is probably not right. I have done lots of Fantic engines and am happy to answer any queries.
Fantic 240 OM.PDF
Fantic 240 PM.PDF