Running on one cylinder

JerrfyLube

Seaman
Joined
Jan 16, 2009
Messages
53
1957 Johnson 35HP SeaHorse...

Did the first real run on this motor a few days ago. Regular unleaded fuel, Valvoline Outboard oil(TC-W3 compliant) at 24:1. Ran it for about 30-45 mins at WOT and cruising speeds and it ran great. When we were idling back to the docks, it started to sputter and was only running on one cylinder. Today, i tried to get it running in a bucket and heres what im finding. Spark is very good on both cylinders. Plugs look good...nice and tan. Compression is 119 on the top, 115 on the bottom. When you first start the motor, it would run on both cylinders for about 2-3 seconds, then the bottom cylinder would die but it would remain running, although, a little rough. I confirmed it was the bottom cylinder by pulling the plug wire.

Its got good spark, good compression and good fuel. What gives? :confused:
 

JerrfyLube

Seaman
Joined
Jan 16, 2009
Messages
53
Re: Running on one cylinder

Turns out its a coil going bad... just incase anyone has the same problem ever... ;)
 

Mas

Lieutenant Commander
Joined
Oct 3, 2006
Messages
1,656
Re: Running on one cylinder

Yup, coils will behave differently warm when they're going.

MAS
 
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