Head Bolts wont break loose
 

I going in for the tear down since I have a huge knock.
2003 predator 500 four stroke...
I got the two LH head bolts out but cannot break loose the two RH. I got the first little snap but thats all I get. I do not want to strip these so I walked away.

How do I break these loose without stripping them? DANG!
Thanks.

PB Blaster is a good penetrating oil if you can get it down to the cylinder threads and let it soak over night. You also may need a heat gun to heat around the cylinder base. This should loosen up stubborn bolts. Also a good 3/8 air impact can help vibrate the bolts loose if you have room to use one rather than a ratchet. OPT

X2 on the PB Blaster.........that is some good stuff. After you got that first snap while loosening did you try to tighten the bolt at all? Sometimes that works.

I took the impact wrench to the bolts and that did the trick. The last one took it's time but it came out.

Thanks for the tips.

Update
 

Well.. the stinkin piston pin circlips were missing and the pin slid out and started scrubbing the cylinder wall. Man that make a lot of noise when that happens....

The clips are nowhere to be seen. Maybe at the bottom of the case somewhere. I got a price of 350-400 for a new sleeve install, new piston assembly and gasket kit from some joint in Ohio. My boat mechanic is recommending I go this route and he is handling the logistics. He said this is a repair kit for this engine and should work fine.

My plan now is to split the lower case and see if I can find the circlips and do some house cleaning in there. I wish I could find the clips without splitting the lower case.....

Have had that happen before when a clip wasn't installed properly and would knock out the other also and destroy a cylinder with the piston pin also. Good luck on the cylinder sleeve kit instead of having it replated. OPT

cylinder repair
 

I'm not sold on the sleeve yet. Actually I'm a bit unsure of it. I see sleeve's online for this engine but not sure if its the right way to go.
I'm still considering Langcourt for a weld and replate. Probably the better way to go.

If they supply their own pistons I would be a little leery as to having a cast iron bore also. Don't think the std Predator piston rings were designed work in a cast iron bore so you couldn't inter change if need be,plus if you had to replace this piston and rings and couldn't find a replacement,back to a replating job anyway! Best really to stay with the replated cylinder and stock piston for it I guess. The cost shouldn't be much different I would think. OPT

Piston
 

What brand of piston should I consider for this 03 Predator 500 engine?
Wiseco, Vertex, JE, Pro-X, SPI , Wossner.....

Wiseco! 4807M09920 Product Detail Information - Wiseco Piston Inc. OPT