12-16-2007, 12:12 PM #1
massive air leak-but never had aproblem-WHY?
O.K-Have put about 40 hrs on my old gpr (Bought it with 90 hours on the clock).
before I owned it it had a major problem on cyl 3, which needed a new barrel and crank work-it had seaized and snapped a rod.
Iv'e been having a problem with a fuel leak which I could not find, so decided to take the motor out to go thro it properly before I either sell it or go big bore.
Re built the bottom end and changed crank seals-there was crankcase damage on #3 but it seemed ok.
Pressure tested it tonight and found 2 leaks in the crankcase around the area were #3 con rod was happily flailing around!-1 in the top section just above the inlet section, and 1 in the lower section diagonally opposite.
It dropped from 8psi to zero in about 16 seconds.
This MUST have been there since I bought it, but I have never had a problem-No running issues , wash looks the same as the other 2 cyls-it's all been great!
Why would this not have shown?
Will an epoxy product (Something like JBweld) do, or do I have to strip the bloody thing and get it welded?
12-16-2007, 12:26 PM #2
Post some pics and point to the areas that are leaking.
12-16-2007, 01:15 PM #3
Exhaust side is deep down between two of the casting webs (webs are fine)
Inlet side again between the casting for the top where the reed valves would bolt in and between where the base gasket would sit.-basically where the pulse line nipple is fitted, but nowhere near the fitting-just dead in the middle.
No major cracks there, just a few pinholes.
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