Is this a compression reading on dry cylinders after rebuild or did you oil them up before putting pistons in. If dry put a little oil in each cylinder pull it over a few times then check again

I found problem number one – cheap coils made. in china -new coils = good spark both plugs

interesting…. I have used several and all work fine …. did you happen to do some measurements on the primary to primary and primary to High voltage pin ??

Don’t feel bad, happens to all of us. But, you do have to verify those compression readings….Needless to say, 18PSI is too low, especially after rebuilding. These engines have such small combustion chambers, minor differences in gage construction make big variations in readings. I would try a few more gages, one without a hose would be best. Be sure the gage is reading in units of PSI also. Hopefully, this is just a gage issue. If not, there is some sort of internal problem(s) causing a lack of compression….

Try opening the high and low speed needles a little bit more….1 on the high and 1 3/4 on the low. When I was starting my 1955 3hp Evinrude it didn’t want to stay running cold at the factory settings so I opened them up quite a bit and it did run. It would start with the choke but wouldn’t stay running. After it warmed up I was able to put it back to the factory settings and it ran well. Tried starting the next day and it wouldn’t start cold again so I opened the high speed to a little over 1 turn and it started fine so thats where I ended up leaving it. I think I ended up with 1 1/2 on the low and 1 1/8 on the high but all motors will be a little different.

• This reply was modified 3 years, 7 months ago by DAN UMBARGER.