Other gp1200r blown rear cylinder

[norcal ex]

SO I did a topend on this guys ski and I sent the injectors to get cleaned/tested and I tested the oil injection and it looked good. Assembled the top end and this happened...

What caused it do you think? It doesnt smell like gas at all. I actually cant smell anything. hmmm

 

[waterfreak]

it looks like detonation from everheating which caused the piston to break apart. When you did your top end did you properly install the exhaust gasket? The reason I asked is because this happened to me after I put the exhaust gasket the wrong way (same motor) and two of the pistons ended up looking like that!

hard lesson learned, especially with nicasil cylinders!!

 

[snowxr]

Also check the rear crank seal. You meam GP1300R, right? EFI?

 

[norcal ex]

yes, I meant gp1300r with the efi. I will check the exhaust gasket but the front cylinder is still fine. This is the same cylinder that went out before the rebuild and it looks the same as it did the first time it went out. I am stumped.

 

[norcal ex]

exhaust gasket appears to be correct. I dont really think this exhaust gasket can go on wrong the way the holes line up. It is symmetrical.

 

[norcal ex]

just looking at the rear crank seal it looks fine. I will have to do a leakdown test on that cylinder to know for sure.

 

[waterfreak]

check the cooling jacket in the head. Could have something interfering in their!

 

[norcal ex]

I will check.... brand new protec head though. Also, How do i check to see if the fuel injection is working? I know the fuel injector is good for sure.

 

[snowxr]

I know it's a pain to pull this ski apart, but they waste the reeds if they backfire. Take a look.

 

[norcal ex]

checked the reeds, still perfect. The head and pipe cooling are good. ughhh

 

[Millatime44]

Norcal,

I know this is an old thread, but did you ever discover what was causing the rear cylinder detonation in your GP1300R?