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Johnson 140hp 2 stroke only running on 2 cylinders?

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Seakerboat77

New member
Hi guys. My 89 J 140hp runs and idles. I can pull both lower ignition wires and engine runs with no changes. They shock me. Reconnect and pull either top wire, engine dies. Is this normal? Switched plugs, no change. Compression 145 on all. VRO replaced with cycle fuel pump. Am I running on just 2 cylinders? Fuel pump not pushing?
 
I power a 21' Ex Coastguard RHIB. Center console. Originally had in/out diesel and I plugged/glassed outdrive transom hole, jackplate and J 140hp. I do 25mph max.
 
I'm thinking the bottoms kick in only at full throttle? Sorry for all my additional posts but I'd be happy if I found out I've been running only on 2 cylinders (70hp instead of 140hp) and it was due to fuel insufficiency instead of WOT metering. Love to double HP and increase from 25mph. Hope someone knows.
 
Hi. Thx for responding. Yes, spark is evident and strong to 3/8" on all 4 cylinders. Also, I worked on it today. I removed bottom 2 fuel bowl screws and lots of fuel there. I swapped starboard carbs top to bottom and vice versa, no change. Reed valves?
 
Some might argue.----So you have good spark.-----Next I Would mark TDC for each cylinder on the flywheel and check to make sure each cylinder is firing at the correct time.----How long have you owned this motor ?----How did it run for you last season?
 
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