[Pis-ton broke]

i recently replaced the head gasket and bearings in my fiat 650 (3 cyl. 65hp) tractor. i,ve never done a tractor before and it was a great learning experience for me and enjoyable.

i my situation, the fait is only used for grass slashing and grader blade work. and not pulling a plough. so its its light work .

number 3 pot had blown the had gasket. there was very low scoring in one spot in the bore, and a lot of water staining too.
i measured the bores up and they all came in good spec.
3 piston hard a tight spot on a ring and light scoring. a bit of pitting, due to water in the combustion, i reckon. the other pistons were good.
because this tractor just plugs around , mainly slashing, and was running fine prior to the head coming off, and i don,t have stacks of money. i cut corners in the repair work. i decided to salvage what i could.

i hand honed the bores, 3 bore cleaned up nice, with light staining remaining and maybe two very small scratches in the bore , that past the finger nail test.

3 piston had a ring catching on a landing, i just filed and fitted the ring to it. on the piston scratches, i filed out the scratches and scoring with a second cut file and then smoothed with 600 grit wet and dry. there was nothing i could do about the pitting in the piston. some pitting was 2-3mm diameter. all pistons were wire wheeled clean.

i left the crank in position ,( i didn,t want to redo the timing). the journals looked very good .i removal all main bearings and replaced with new. plus new clutch throw out bearing.

i got the head decked and should have got new head bolts , but none available. got the injectors tested, they were good. did nothing to the injector pump.

reamebled the engine , and used copper head gasket spray on head. got a brand new water for $250, what a score for a 44 yo italian tractor. new secondhand radiator and filled with a mixture of soluble oil and water. serviced air cleaner, old oil bath type.

got it running pretty much straight way, it runs well, better than before. it doesn't smoke , maybe a bit when hitting throttle. starts immediately. i,m really happy with how it turned out. ive used it many times since and all good.

if the tractor was used for commercial use , i would have done a more proper job, ie , new pistons, and liners etc.

jcb are good english tractors and i reckon you with be able to get lots of parts for them.

keep us up to date, i love to here of the "nuts and bolts " detail of a build.

you could try a wire wheel on a 4 -5 " grinder for cleaning old gasket material on cast iron (or steel) only. will save a stack of time.