Compression question

[johncj8989]

Is a dry compression reading in the 128lbs range normal for a motor that has been rebuilt and only started a couple times? I was thinking the numbers are a little low but maybe that could be explained by the fact that the new rings have not been seated yet.

Thanks

[pjv911]

It is very normal to have lower than spec compression on a fresh engine. Even more so if the engine was tested cold. However it would be hard to guess since we could be talking about your lawnmower going by your description. In any case if your compression is even within 5-10% I would suggest that you have no problems there. If some are lower by a larger margin then you should do a leakdown test which may show a tight valve.

Kurt Williams

[johncj8989]

Thanks curt. But I must report that my Porsche Badge sporting beast of a mower is in need of a total rebuild.

3.6 mower conversion perhaps?

[3.2 CAB]

Sounds about right for a fresh engine. Should get better after everything seats and seals in.