So, nearly 4 years later and at last i've leak tested my engine and it ain't looking good. Here are some pics and details of my findings for you all to see first before i go splitting the crank cases. Please tell me your thoughts;

Here is the tester - the exhausts are blanked by nothing more than a piece of rubber about 10mm thick held hard over the exhaust holes by pieces of steel plate i had left over from when i made my flash flywheel holding tool.

For the parts of the tester in the photo - 40mm PVC waste pipe fits PERFECTLY into the carb boot, i just chamfered the end to make it slip in easier. Onto this i glued a 40mm PVC cap (these are both typical plumbing parts for use under kitchen sinks for example). I hole sawed the cap and threaded in the brass fittings, some of which i dug out of the depths of the garage, others i sourced from a local diesel mechanic business. Its all PTFE'd together though i also used silicon to get the brass fitting to seal into the PVC cap.



I pumped up to 8PSI (if the gauge can be trusted), drowned the engine in soapy water and found the following leaks;

These seem to be on the joint between the crankcases, not the the base gasket.





This shows air getting past the flywheel side crank seal - though i'd have thought some leakage past this seal would be acceptable. I just wonder what is considered an acceptable size leak?



Thanks very much for any advice.

Dad reckons seeing as its always run well and started easily that i'll be wasting money if i split the cases to try to seal them up better. I'd also be replacing the outer crank seals as part of the job if i go ahead with it. The engine has done 115kms since its new crank and 300cc kit went on.
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