compression #'s

[smokeeater]

I have a 1996 Evinrude E8REDD 8 h.p. Does anyone know what the compression should be?

 

[NathanY]

Re: compression #'s

Anything above 100lbs is good and both cylinders should be within 10% of each other.

 

[smokeeater]

Re: compression #'s

Thanks...now I've never done a compression test on a boat motor. Should it be running or is a few pulls on the cord good enough?<br /><br />As well I got new plugs for it (champion), do they need to be gapped to a certain point??<br /><br />Thanks again for the help everyone.

 

[jim dozier]

Re: compression #'s

Warm engine, plugs out, full throttle. Check book for correct plug gap don't assume they are correct out of the box.

 

[smokeeater]

Re: compression #'s

I got the gap from Evinrude...<br />But both plugs out??-if I only have one comp. tester leave the other one in then?

 

[NathanY]

Re: compression #'s

Yes leave both plugs out. That motor will run on one cylinder. Give it about 5-6 pulls to peak out the guage.

 

[smokeeater]

Re: compression #'s

Oh so the motor is not actually running by itself? With 5-6 pulls I get the impression that you pull and check the guage right?

 

[jim dozier]

Re: compression #'s

Yes, if it was an electric start you would just crank it a couple of seconds or if its manual you just pull it 4 or 5 yanks. Run it till warmed up if its runnable and then pull the plugs out. Use a gauge that screws in the plug hole not one that you hold in it.