Reusing a gasket (well o-ring)

[Krispy]

-Skipping all the details on how I came to be in this situation-

I have pulled the head off of my 787 to inspect my top end.

I noticed this engine is sealed with 4 o-rings. This is new to me as I am used to multi layer metal gaskets.

Everything looks good under my head so I want to re-assemble.

Can I use the old gaskets?

My past experience says 'no" but I thought I would ask since this is an O ring setup.

Thanks,

Chris

 

[racerxxx]

I'd re-seal it with new o-rings, not worth the chance. Be sure to torque the head to the proper torque and in the correct pattern from the manual.

 

[Krispy]

Racer, you are the good angel on my shoulder....but let me play the other side and see if it changes anything.


How about temporary usage, just to get the engine up to temp. (Running on hose only)

I have some water in the cylinders, and want to guard against rust. Manual says to clear all the water then take engine to operating temp, I assume to turn the remaining water to steam, and out the exhaust.

At this point as I turn the engine over (head off) only a fine mist of water/oil mix is coming out, but I am worried about protecting the rest of the engine (bearings) from rust until I can get all the moisture from within the engine.

Thanks,

Chris

 

[CReynoldsMIZ]

The ones on the head? Well, you can reuse them...i have taken the head off before and reused the orings, but i am cheap even tho i probably know better and should have replaced them. But, in your situation, put them on and torque it down correctly and get it back to the lake to burn the water out of the engine immediately! You dont really have time to wait for new ones to get in. Get it running, and then take it back apart and put new ones in after you know your engine is still safe

 

[racerxxx]

I just switched shoulders :reddevil:, if one of the ones on the cylinder leaks water into your cylinder and you hydrolock your engine and blow a rod in two pieces, let me know if it's worth the $$$ on the o-rings. Yes, you could probably do it and it would be fine for temporary, just don't make it temporarily permanent. If so, you're the one squeezing the trigger with the gun at your head.

 

[CReynoldsMIZ]

Yup...what he said. Just do it as a temporary thing...how did you get water in your engine to begin with/how long has it been in there?

 

[Krispy]

Yup...what he said. Just do it as a temporary thing...how did you get water in your engine to begin with/how long has it been in there?

I did some pump work and forgot to connect the bailer lines on my test run, hull filled with water.

Racer, it isn't about the $20 for gaskets. It's about keeping rust off the bearings.

 

[Krispy]

A quick update. I ended up putting the head back on and torquing in the proper sequence and in 2 stages per the manual.

It took quite some time to remove all the water from the engine. 2 things I did made it a bit easier that I don't see mentioned often. I disconnected the fuel line from the carb so I wasn't pulling more fuel into the engine. More importantly I disconnected the pulse line to the carb and took the carb apart (found some water inside the fuel pump body from the pulse line).

Still after removing the bulk of the moisture from the engine it wouldn't start. Finally I checked for spark and found I had a VERY weak spark. I went to my rear electrical box and found the small ground wire was barely attached (2 strands of wire remaining) I replaced the ring terminal and was able to fire it up!

I took it to the lake and left it on the trailer and just ran it in the water for a while. I noticed a new problem when on the trailer with the seat off but I will start a new thread.

I have ordered replacement gaskets from SBT for the head and exhaust (see new thread) and I will replace them before running the ski again.

Anyway, thanks for the help all!