[JMT13413]

I just pulled oped my seized motor. Turns out the cam chain had snapped. So I know I need to replace the chain, tensioner, and guides. Anything else I should check? Also anyone know a place to get all the parts?

 

[LiLBull]

Yes check every thing there isnt much in there.If you dont know what your looking at and want to save money (there is no saving money in engine building except for labor) take the disassembled engine to a machine shop ,they can mic things up and tell you what you need.
siezed motor you would want to rebuild it to at least stock specs.
Dont skimp on buying parts if you plan on a good motor,buy everything that wears out.
Do it right inside the motor and you will be smiling out side when you ride it dayin day out with no problems.
These engines are getting old so internal parts are getting harder to find . So its search the web time for internal parts.
Look for older dealers they ussually still have stuff or older model specific venders they too ussually have old stock.
best place to begin is ebay alot of old stock is listed everyday. Good luck.
George



Edited by - LiLBull on Dec 18 2005 08:24:40 AM

 

[Geeto67]

if the cam chain snapped then you know there is a good chance there is a bent valve in there somwhere, probably a nicked piston as well.

 

[JMT13413]

The pistons look good, but I have some bigger ones for it. The valves were done not long before it seized, I haven't looked at them yet. Upon inspection I found one of the little stud that adjusts the valves tangled up in the cam chain. So it looks like it fell out then got caught in the gears and snapped the chain.

 

[Geeto67]

When you say seized do you mean the crank won't turn? Explain how it seized. When the valve train stops spinning and the bottom end continues to spin there is going to be at least one valve open espically if the valve adjustment nut came loose. That means the piston will have contacted the valve (there is a slim chance this did not happen or the piston hit the valve and closed the valve on that side). Even if the valves wer ebrand new and the chain let go on the first revolution there is probably a junk valve in there now. Even if the valves look good mic them up anyway. If you haven't pulled the head yet, it might be that the valve bent sideways in the bore and stopped the piston. I have hade engines size on me this way (including a 510 cadillac mill that bent every valve when the timing chain went at 5500 rpm).

 

[JMT13413]

Yeah seized as in the crank wouldn't turn. I have the head pulled off, thats how I found that is was the cam chain. After pulling off the head all the valves appear to be closed. So none of them are bent bad, but I don't have a valve spring compressor so I haven't had a chance to pull them out yet. I want to atleast lap them while I have it apart.

 

[Geeto67]

how did it seize the bottom end? Oiling issues? If the cam chain broke that usually stops your engine from running. The only way I can figure is that the cran seized and then the cam chain snapped from the sudden stop. If that is the case then I would check the rod stretch, have them checked for cracks and straightness and have the crank checked for straigness and cracks as well.

If you hydrauliced the pistons then you could have oblonged the little end of the rod and the piston pin.

Sounds like you have a lot of issues going on with this engine requiring a complete rebuild. start with the cases and have them line checked and bored if necessary, then make sure the crank is 10/10 and then new rods, pistons, etc..



Edited by - Geeto67 on Dec 20 2005 10:35:50 AM

 

[JMT13413]

The crank spin's freely now, the only thing that stopped it from turning was the chain being tangle up in there. One of the valve adjusting screws fell out and got inbetween the chain and sprocket breaking the chain. The motor was rebuilt not long before the chain snapped. Most eveything seems to be in good shape.