Well engine finally gave up

Havent been on in a while as some little **** tried to steal the local telstra wires, over a month later and i finally have the internet back.

The little zxr engine finally gave up and dropped a valve at 18.5k rpm, result is a valve which is now rectangular, ruined cylinder head, piston with a big hole through the middle, sleeve with some gouges and bits of piston and valve everywhere, also found an acorn in the sump which doesnt seem right.

everything else is still perfect but i think i may just get a new engine and rebuild this one over time as parts become available. So anyone got an A model engine they want to get rid of?

 

inlet valve went, it has misfired very rarely at high rpms before which i though was ignition/fuel related but looking up valve float it may have been the cause. its a shame as it was finally running well.

 

little acorn looking thing off a tree was in the bottom of the sump along with a bit of grass.

 

acorn and grass are gone as i already cleaned the sump out, have no idea how that could get in there, also found gasket goo on the oil screener and some bolts on the crankshaft.

 

thats the plan eventually but i want another motor aswell for the mean time (want to rebuild my current one properly then overhaul the new one), apparently the a and c model have different pistons and sleeves though. Finding another engine has proven to be pretty difficult aswell, i have only found c model engines and they have low sus k's.

atleast i have a chance now to overhaul the brakes and will have to clean the carby's as there is bits of piston covering it. Also think i may have to rip the engine apart and clean it throughly as there is piston bits all over it.

also need a new clutch on the motor i have and possibly cam chain and tensioner.

 

so i finally got another engine, apparently has 31k on it, got it from a wreckers it came with no starter motor or stator cover, decided to check the valve clearances and whatnot. Didnt even get to check them as i noticed the cam chain has over 1cm of slack in it and i could probably pull it off the exhaust side if i wanted, rocker cover has visible marks where it has been hitting.

these blokes said the engine was running as they all have to run to be sold, but surely they would have heard the cam chain clanking like crazy. I really dont want to spend another few hundred on cam chain and tensioner wtf can i do here.

 

tensioner is well and truly done, spring is actually bent in several spots the rod is marked by the bearing in several spots and the bearing itself is rooted.

 

seems my posts were deleted during the fzr250 migration, got the engine running had to swap over the tensioner as the old one was rooted, cam chain may need doing in the nearish future as im guessing previous owner was not good with maintenance.

lots of carbon on valves, clutch is slipping, tensioner looks to be from the factory. Valve clearances were ok, all right on lower spec or slightly out but will do them another day ( have alot of shims from 2 previous ruined cylinder heads)

carb boots were hard as rock couldnt even get carby's over them, vacuum lines were rooted as in may as well not even have them on, should have taken the head off and cleaned it might also do that in the future aswell but just happy to have the bike running again. not sure how they got the engine running and didnt notice the cam chain smacking the rocker cover but whatever. Everything else seems ok, pulls well but might not treat this one as bad as my old engine until i get the other one fixed.

 

bike runs well and idles ok, clearances have to be abit more out of spec to do that, nearly all are just within the tolerance might do it when my garage warms up abit, feels like im working in a fridge.

 

so cant find the vacuum leak, carb boots are good and vacuum lines are brand new, its definetly leaking somewhere around the boots though as i sprayed some start ya bastard around it and the revs rose alittle, need some ideas of what to look at next.

clutch is absolutely terrible cant go half-full throttle on a bumpy road as the clutch just slips, so guess thats next.

i think the valve stem seals may be leaky, didnt ride it for a couple days and on start up it did smoke alittle, but will deal with that another time, not using oil from what i can tell or smoking while running.

bit more to sort out and then rebuild the old engine.