A couple months ago I purchased a 1994 Seca II as a project bike. Immediately after bring ing it home I did a compression check (with the carbs fully removed), and found that all cylinders had even, but extremely low, compression— about 30psi each. Wet compression test raised each cylinder a small amount, about 5 psi each.
Based on this I suspected maybe a cam timing issue rather than rings, but after setting cylinder 1 to TDC with the “T” timing mark on the crank, both camshaft indicators were visible through the holes, which I think means everything is properly in time?
Additionally, the valve clearances for the intake valves are all seemingly tighter than my thinnest feeler gauge, (.0015in) which is so much tighter than spec. For reference, I measured each set of valves when the cam lobes are pointing away from each other, which is the “T” mark for cylinders 1 and 4.
I looked into the cylinders with a borescope and found lots of carbon buildup but not sure if that would point to another problem. The bike turns over freely and all of the valves seem to be actuating fine.
Am I missing something here? I just find it hard to believe that all of the intake valve clearances are equally out of spec by such a massive amount, causing the low compression in every cylinder. Hoping for some advice on where to go from here.
Thanks
