THD Wisconsin compression

fixerupper · May 30, 2015

Just for my reference what should the compression be? This THD is a two cylinder flathead from the seventies or early eighties as far as I can tell. Neighbor gave it to me after sitting maybe 30 years. Valves were stuck and I freed them and cleaned a little carbon out from under them. Got it running, it starts right up, ran it wide open for a half hour or so but one cylinder was weaker. Compression test hot and dry was 80 and 60 so it's low on compression. There is no cylinder ridge and the cylinder walls look good, I just don't think this thing has all that many hours on it so a valve touch up should get it back up in good shape. Anyway, I pickled it and will put it away for awhile. Just wondering what a general compression should be on this engine. 120 or so?

fixerupper · May 31, 2015

(quoted from post at 09:57:13 05/30/15) Just for my reference what should the compression be? This THD is a two cylinder flathead from the seventies or early eighties as far as I can tell. Neighbor gave it to me after sitting maybe 30 years. Valves were stuck and I freed them and cleaned a little carbon out from under them. Got it running, it starts right up, ran it wide open for a half hour or so but one cylinder was weaker. Compression test hot and dry was 80 and 60 so it's low on compression. There is no cylinder ridge and the cylinder walls look good, I just don't think this thing has all that many hours on it so a valve touch up should get it back up in good shape. Anyway, I pickled it and will put it away for awhile. Just wondering what a general compression should be on this engine. 120 or so?

OK, since i had oil on the cylinders for storage i did a quick compression check wet; 120 in one and 124 in the other. I guess i answered my own question.

THD Wisconsin compression

fixerupper

Well-known Member

fixerupper

Well-known Member

Similar threads