Pin holes in cylinder!

Quinc

Quinc

Buy a Superjet
Location
California
Just can't win.. Finally get the bob dialed in (chased epic hx3 issues, chased bad carb issues, hull repairs) and now this... Ski was running best it ever has the last few months and then I get an air leak.. I thought I cracked the cylinder but after cleaning off the paint I cant even see the holes they are so tiny.

Is it possible to find out if the water jacket is leaking into the cylinder? Some kind of dye or something I can pressurize the water jacket and find any seepage?

 
wavewarrior

wavewarrior

Location
sarcastomento
I had water leak out though that same spot. Had to grind out area and tig weld it. JB weld did not work for the quick fix and had to pull the head to do it right.
Still working fine on the ski in the avtar pic.
 
R

restosud

known failure point .either get it welded if possible but will eventually probably crack again or get another one.
running a girdle helps a bit
 
Quinc

Quinc

Buy a Superjet
Location
California
I cleaned and dried the cylinder, put the head back on it and filled the water passageway 3/4 full of soapy water. Blocked off all the water passage ways around the exaust ports and one of the head outlets. Then used my pop off tester to fill her up with 15 pounds of pressure. Then shook her every which way let it sit upside down, side ways, etc and no water leakage. So hopefully these are the only pin holes. @Nuklear6 gave me some tips to fix it and fingers crossed it holds for a while.
 
Christian_83

Christian_83

Xscream
Location
Denmark
Quinc said:
Just can't win.. Finally get the bob dialed in (chased epic hx3 issues, chased bad carb issues, hull repairs) and now this... Ski was running best it ever has the last few months and then I get an air leak.. I thought I cracked the cylinder but after cleaning off the paint I cant even see the holes they are so tiny.

Is it possible to find out if the water jacket is leaking into the cylinder? Some kind of dye or something I can pressurize the water jacket and find any seepage?

Click to expand...

If you do 2 pressure test, cooling side (looks like you done in the video)
and combustion side - if the cooling line leaks into the cylinder i would suppose the combustion pressure/leak down test to fail.
If the combustion test is ok, i would think you "only" had an issue with the cooling line? Correct if im wrong.
 
Quinc

Quinc

Buy a Superjet
Location
California
Christian_83 said:
If you do 2 pressure test, cooling side (looks like you done in the video)
and combustion side - if the cooling line leaks into the cylinder i would suppose the combustion pressure/leak down test to fail.
If the combustion test is ok, i would think you "only" had an issue with the cooling line? Correct if im wrong.
Click to expand...

I presure tested the combustion side in the video. I can see the little holes in the top of the transfer port. =/
 
Quinc

Quinc

Buy a Superjet
Location
California
-Soaked green Loctite in the transfer port that is leaking then wiped up the excess
-A thin layer of jbweld over the holes in the transfer port

24hrs later she is holding 10psi for over 45 minutes now. *also turn the engine over by hand a few times to see if the psi drops. And no bubbles in the soap. Hopefully it holds up after running... :confused:
 
Prickster

Prickster

Location
Florida
I have seen it a few times. Normally when someone is porting the transfers to thin. This started as a small hairline crack, hit it with a dremel on low speed, and exposed this lovely hole. Tig welded and back into service.
 

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mthomps

mthomps

Location
Cleveland
If you have something local get that thing dipped im flourecent penatrant and have it inspected. That will show you everything. I used to prep parts for inspectors and they'd find tiny pinholes that could ruin a part that youd swear were invisible
 
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