Smokin, Knockin, now wont start.

[aron450r]

Well im just gonna make a long story short, Bought it like this. Now it smokes just like a 2 stroke, well I shut it off and started it again and now its knocking, got louder and louder. Well I checked the oil and was dry, so I thought put so new rings in it and some oil and maybe the knocking will stop and wont smoke. Well I put in oil and now it wont start, acts like it lost all compression, turns over as if you had the kill switch on but never fires, sprayed crab cleaner in carb still wont fire, new plug still the same, is it locked up or blew up or what? Just seeing what everyone thinks before I take it apart tomorrow.

[brian76708]

well one way you can tell if its seized is by placing your hand over the exhaust and if air is coming out than its not seized.

[aron450r]

Air comes out, then kinda barely sucks back in.

[RaginRedneck]

Originally posted by aron450r
Air comes out, then kinda barely sucks back in.


Not sure....stuck valve maybe?

[brian76708]

then its not seized idk whats rong have you checked the simple things such as fuel and spark start there first but i have no clue about the knock

[aron450r]

i just hope it isnt to bad, guess ill find out tomorrow, any advice?

[brian76708]

buy a clymer manual if you dont have one already

[aron450r]

ok

[2muchquad]

yeah your topend is probably shot,if it was knocking and smoking,and now wont start,chances are you had a piece of the piston break off or rings.Good luck with that:)

[the Z Man]

Could have jumped time too...

[brian76708]

Originally posted by the Z Man
Could have jumped time too...

i was thinking that to

[aron450r]

thats what i think, and hope.

[aron450r]

good call Z, dead on, it jumped time badly, so we put it back in time, put it together still didnt start..so i said lets see whats going on, tore it down and comes to find out the timing chain was broke. rings are shot, so im called a buddy that works at the dealer, hes my hookup lol, discounted rings and chain, im hoping that will fix the prob...still hopeing its stock 400ex, the guy said it could be a 416/426 so i guess ill have to take the piston with me or does someone have a better ideal? if its stock he has everything in stock, if not he will have to order the rings...but found out it does have Hot Cams, not sure what stage...

[2muchquad]

i would go with a new piston while your in there,you may need a bore job,a new piston may tighten things up for now but it wont last as long as it should if it needs bored.400s are pretty rugged but they do wear out from time to time;)