grib

Looks like the bearing cage is missing, could have been a plastic cage that has disintegrated?

I clean my 240 exhaust by burning it out, I have used a blow torch in the past but it takes ages, now I build a fire and put the exhaust on top - get it really hot and wait for the smoke to stop coming out, you will know when it is clean. You will get a hundred opinions on the amount of oil to use, but I am happy running my 240 at 66:1 using fully synthetic trials specific oil, usually Putoline. Have you changed the gear oil? If the LH seal is leaking you should get noticeably less back out when you drain it after doing a trial. I have noticed mine running 'flat' as you describe it when it has been burning its gear oil, different smell to the exhaust too.

My preference is 11:41

Another method which works well when removing the flywheel is to tighten the puller bolt and then give the head of the bolt a sharp tap with a copper hammer.

The hand drawn diagram above is correct for wiring the 240 stator to the later type coil. I would suggest taking the flywheel off and checking the stator, the only way to remove the flywheel is with the correct puller.

Hi Hap, I have attached the parts list but I don't have the wiring diagram - I have attached the handbook for a 307 which contains the newest Fantic wiring diagram I have, but a 307 is air cooled so doesn't have a fan. Fantic electrics are all very similar, the fan on your K-roo would probably have a rectifier in the circuit somewhere...... Fantic_K-roo_250_94Mod.pdf Manuale-307.pdf

Grimeca hubs were used on lots of different bikes of that era - the wheel is probably off something else.

I have tried ATF, I found the clutch was OK but a bit on the grabby side, but it made the gearbox very notchy - quite difficult to get in to neutral.

Parts list for the engine, and (Italian) handbook attached. I use fully synthetic Putoline trials oil at 66:1 in my 240, and Putoline light gear oil in the gearbox. Fantic 125-200.pdf Manuale-Uso-Manutenzione-Trial200.pdf

You cant replace one crankcase - they are machined as a pair. I would agree that having it Tig welded and re-machined would be the best solution.

The spring is 3.7mm inside diameter, 5.4mm outside diameter and 10mm long.

There must be a suppler of Dellorto parts in Canada? I will measure a spring tonight so you have the dimensions as an alternative though. If you had the throttle valve screw one turn out from fully in that will be the reason for your high revs - unscrew it until it holds the slide open by just a small amount (0.5mm or so) then use it to adjust the idle speed with the engine running.

Jerry there is no air screw on your carb, only a pilot (fuel) screw and a throttle stop. Is it the smaller screw without the external spring that you have 1 turn out?

Without a hole in the pipe no fuel will be drawn out of the carb, the two stubs are float bowl vents and need to be open to atmospheric pressure, a lot of people (me included) don't use a pipe at all on the vents. The 'pin' in your photo is the float needle which allows fuel to flow in to the carb. The needle should be a free fit in the other part (the needle valve), if you turn it upside down it should fall out. It could just be gummed in place with old fuel/oil, but the chances are it needs replacing, if it doesn't shut off properly you will have crankcases full of fuel. Page 4 here; http://dellorto.it/wp-content/uploads/2015/10/dellorto_manual.pdf

Is there a hole in that yellow pipe?

It is only held on by the drain plug/main jet holder, it also fits over the bottom of the choke jet with an o ring - its probably this that is holding it, there is an o ring between the bowl and carb body too, no gasket. It should come off if you wiggle it enough.

I read this thinking it was a 240 - N3 is the correct plug with a 3/4" reach.

What plug are you using? It should have a 1/2" reach.

Not really - tighten the hub nut to the torque in the handbook, and adjust the clearance on the push-rod.

run a file over the edge, or try to scratch it. I would expect they will be hardened.

The 3.4 to 3.54 is my interpretation of the information in the parts list (measuring the inner spacer might confirm this - I would expect it to be about half of (3.5 minus the circlip thickness)), otherwise - Yes.

How thick is the inner spacer? On page N5/2 it looks like the single spacer is 3.40 to 3.54mm thick - the total thickness of the two spacers on the earlier gearbox would be the same as the single spacer.

Yes there is a shim/spacer there - look at pages 1&2 N5 in the parts book. The earlier gearboxes had a spacer then the circlip and a counterbored spacer/shim that fits over it, the later gearboxes had no circlip and just one spacer. I dont have dimensions I am afraid, the I/D and O/D will be the same as the inner spacer and the counterbore will be to clear the circlip, the thickness is the missing dimension. Bill Pye or Bob Wright might have one....

I haven't seen a Fantic engine with a roller bearing on the ignition side, but the 'newest' one I have taken apart would be about 15 years old at the time... I am just going off the parts list and what I have taken out.

There isn't a crank end float measurement published anywhere, and there are no shims on the crank (the only 'shim' is a spacer about 0.5mm thick behind the LH bearing on the output shaft in the gearbox). If you pull the RH case down using the case screws then obviously all of the clearance in the bearings is taken up with the inner races being pushed outwards, to counteract this I use a spacer under the flywheel nut to ease the RH inner race inwards and centralise the crank in the bearings by feel. The crank bearings are per the parts list - 6305 C3 and 6304 C3 (the C3 clearance spec is important), I usually use branded bearings like SKF, Koyo or similar as they don't cost much more in real terms than 'budget' parts. Not sure where you are in the world but I am in the UK and use the Simply Bearings website for all bearings, seals, o rings etc.