Right after i took my engine out to repair a snapped exhaust bolt, i put everything back together now and started the bike up everything good so far. Then it just cut out on its own when reving on the stand, so i stated it back up, and it would die if throttle wernt given. now i leave it 10 mins and decide to take it for a spin then the fu**ing bike does'nt start. So i decied to take the engine back out again :rtfm: and i notice the following on the head and piston, although when i first took the head and barrel off im sure there was water in there. there is little dimples all over the head and on the top of the piston, there is also a lintel bit of metal missing from by the top piston ring Any way what do you lot thing is wrong with it, the circlips are fine and didn't do this.
id say get a new barrel and piston im no expert on wht caused it but i can see its fucked. nice pipe though laser x pro ftw. wish i could get one!!!
those marks on the head and piston look liek that bit of piston ring bouncing around inside tehre your lucky it didnt find its way into a port otherwise it would of been majjor seizeidge, marks on the cylinder head shouldnt cause to much problems wil affect compression slightly but nuthin major , marks ont he piston on the otherhand will be a different story that will affect igniton and the missing peice of piston ring will stop compression thats probly why its not runnign right, you could get away with just a new piston kit, check your crankcase for that peice of piston ring otherwise its just gona fuck it up again sorry if none of that makes sense im fucked unk:
what could of caused this to happen, as i don't want to put a new piston kit on to find out the same thing will happen again.
bit of piston ring catching on a port most probly , thats caused by worn rings , check theres no cdmaages to the posrts on teh cylinder
it was only running for like 3 mins on the stand just idling, before this happened the bike was running fine, jetting was fine, etc. this happened when i put my barrel, head and piston back on after getting the snapped exhaust thread out.
right i just split the engine cases with the help of J-nitro, and the main bearings were looking ok so were the seals, i also had another look at the piston rings and the good to, so any more suggestions of what caused this to happen to the head and piston?
splashout them mains are fucked man you have to change them they are whistling when you spin them just get first of all piston kit mains top end gasket set new spark plug clean you cases out and cover them and freeze you crank with wd40 and a sandwich bag
the cause was most probably badly fitted rings. it could also have been the locator in the piston coming out. chances are it will have stressed the big-end, you may get away with ti you may not. if it was my engine it would be having a full rebuild as matter of coaurse, any debris still floating around in the engine willl cause chaos with the bearings and new top-end. and no, i dont think you'll get away with re-using the barrel after that.
the crank is out now, im going to get new main bearings, and i have also ordered a polini sport 70 kit. how can you check that the main bearings are ok to use/.
erm, gotta feel for play (up and down) and not excessive sideways play. if in doubt drop a replacement crank in there or get someone to check it.
yeh i checked yesterday it seems good splashout, theres supposed to be no up to down play, which there wasnt and only a little bit of moment side to side
check for discolouration of the rod and pin, check how it feels dry and then with a splash of 2T oil on the pin. Up/down play as previously mentioned.
