Gtx 787 Rebuild question

[Bruce20]

I rebuilt the top end on my GTX and the one cylinder leaned out, burning up one of the pistons. To get that piston out, I had to take of the exhaust manifold. Do I need to unbolt the cylinder that wasn’t burnt up, so I can align the jugs or can I just put the other jug in place and bolt the manifold to the two jugs. Thanks.

 

[mikidymac]

You need to pull the other one to install a new base gasket anyway. Never reuse a base gasket.

 

[Bruce20]

Aw man, even if it had been on for an hour of use. It is such a pain getting the rings to compress into the jug.

 

[mikidymac]

Sorry but yes.

 

[mwat65]

A band clamp is an easy way to compress your rings.

 

[racerxxx]

Before you even put the top end back on you need to find out why it burned up in 1 hours time. Is this the same cylinder that went bad before prompting the first top end? I would dig into the fuel system. Have you replaced the fuel lines, rebuilt the carbs etc..... If not in another few hours you're gonna be right back in there. The easiest way to compress the rings is with your fingers IMO

 

[Chester]

On PWCs, you can't do just a top end. You must completely tear apart the engine, inspect the crankshaft, and replace the crank seals. Then pressure test the engine.

Chester