hey, so I juts got a ltz 400 and knew it needed work and knew it didn't run. I was going to check the valves but found a snapped cam chain. the intake cam froze up on the journals and luckily it froze up closed so I didn't mess up the piston. at least it doesn't look like it. I was able to un freeze the cam and here are some pics. what should I look for? what parts do I need other than a new chain? and im pretty sure the oil pump gear is stripped. also it before I knew it was the chain it does crank over pretty fast so is it a dropped valve? thanks. and also the black spot on the piston is just carbon but looks weird.

 

Strip the oil pump to find out why it seized, metal fragments inside it would indicate problems elsewhere. Did you run it short of oil? If so, it may need new piston rings as the oil went somewhere, though the piston would probably have a lot more carbon on it if the engine was burning oil. Check the small end for seizure and the piston skirt for signs of seizure, if the cam got short of oil these items were too. The valves look OK, with a broken cam chain they were not letting any mixture in to compress.

 

yea I got it not running so I don't have all those answers but everything else looks well lubricated and there was plenty of oil in the tank. but the oil was nasty. super black, so could it of been just really dirty oil not lubricating well? thanks

 

bump anybody?

 

most of the time when the cam chain breaks the chain fall to the bottom of the motor and can get bound up and crack the cases or mess the crank up, u need to check it out, ran out of oil for some reason, no or low oil, bad pump, oil goes to head/cams first. could be dirty oil but pump is a more likely.

 

thanks, yea I got lucky and it got bunched up but didn't do any damage. oil is all over everything in the head so im thinking it could of been bad oil. I got new cams and a new chain. how do you set the timimg? -thanks

 

u need a book or the info on setting the timing but all the bikes I have ever seen u put the piston at TDC, make sure the piston is at top of the stroke, line up the marks on the cam and head, if some body ran it out of oil and didn't prime the oil pump it wont have any oil pressure.

 

ok thanks. took the pump apart today and its all scared and hard to turn. so will get a new one of those. also how do you prime a oil pump? just make sure its full of oil? -thanks

 

it either ran out of or very low on oil or pump went bad, combo of both would be my guess, the book will tell u how to prime the pump either fill pump with oil some how or spin oil pump shaft with a drill, best thing is get a book

 

ok I will thanks.