blew up again! 8 hours later.... help?

[daveyboy440]

well i have a 2001 ex with the 440 kit, rejetted carb, aggressive cam, all headwork done (bought it all like that). first time it seized up driving then sat there for 5 minutes and started back up but 15 minutes later the timing chain snapped. put new guides in and chain. valves and piston all ok. drove around again and bam seized up again but this time it never broke loose and the timing chain doesnt seem broken. any ideas? (besides just throwing a heavy dudty chain at it)

[lpmaster]

well im not sure what you're saying generally if your motor siezes in doesn't unsiez but.....do you mean the started wont turn in it after is stalls? this is a common problem with an old battery and a high compression piston i believe not to mention it sounds like you may ahve some kind of bind somewhere, possible dry bearing or something, also are you making sure there is plenty of oil in it?

[daveyboy440]

see thats the thing, i actually think its the oil pump not getting oil to the top end. it seems like its like that

[PismoLocal]

If your piston did seize and then break loose your sleeve would be scratched to all hell.I doubt your quad would run very well. If you think you have an oil problem check your oil screen and see if there is anything in it. take off your head cover and inspect your cam/rockers for wear. Also check your headgasket areas for leak.

[lpmaster]

we definatelt need a little more info....if you're top end isnt getting oil, thats clearly a problem there would be evidence instantly fo that once you pulle the head off. if its not an oil issue. i would be sure your rod play is within spec sound liek your cranking could be going or is gone...

[moorhous]

its your crank!

[underpowered]

have a few idea. check the oil filter, see if it is in backwards, that would cause oil to not get to the top end.

could also be jetting. if you are to lean, it could be getting to hot and heat seizing.

like someone else said, could be crank bearings and/or rod bearing.

could also be just a clogged oil passage, may have gotten some gasket maker or something in one of the passage ways during instalation.

there are a few different things it could be. no matter what you are looking at atleast a top end tear down.

[daveyboy440]

ill give more info, last time it seized it ran again 10 minutes later then just b4 i got it home the timing chain snapped. I openned the engine up and the chain guides were chewn to nothin and all the plastic from them was packed in the small screen in the bottom end. i cleaned it all out put a new oem chain in and guides and ran 91 octane with octane additive. then 8 hours later here i am again. (last time i took it apart crank was good cam was good and piston/pot were good.)

[firefighterjosh]

sounds like there is alot of damage.

If there is something major wrong, which it sound slike it I would prally tear it down and starting replacing stuff.

vavles
Rod
piston
springs

I would replace everything and just start over.

While you have it apart might as well clean out the oil pump maybe replace it....make sure your lines are in teh correct spots...just some ideas

[daveyboy440]

someone told me the trans could be binding up (since theres no top end damage visable. hear anything about that? oh ya and does anyone know a good place to buy a service manual for this 2001 ex?

[woodyzr2]

http://www.clymer.com/