Johnson 88 SPL rough idle

M

mikecairl

Cadet
Joined
Jul 6, 2004
Messages
6
Have owned this engine for 6 years and has always run great. The other day I was running wide open and the engine just died. After I restarted it the idle was rough but ran fine at any other speed.<br />I sprayed carb cleaner in the carb, checked all fuel lines, checked spark plugs all looked fine but still put in new ones, new spark plug wires this spring, checked all coils and have had no luck. Any ideas??
 
R

russeller

Petty Officer 1st Class
Joined
Jun 19, 2004
Messages
218
Re: Johnson 88 SPL rough idle

when is the last time you did a carb rebiuld ?
 
M

mikecairl

Cadet
Joined
Jul 6, 2004
Messages
6
Re: Johnson 88 SPL rough idle

Never. I knew the previos owners and there were very few hours on the engine before I bought it.
 
W

Walker

Captain
Joined
Jun 15, 2002
Messages
3,085
Re: Johnson 88 SPL rough idle

Do a compression test. I hate to hear that an engine died at full throttle.
 
P

Puttdrainer

Recruit
Joined
Jul 10, 2004
Messages
4
Re: Johnson 88 SPL rough idle

I am having similar problems with my 88HP Johnson approx 1990..... and Ive been looking at the repair manual. It says the Fule pump diaphragms are fragile and a defective one produces symptoms that appear to be an ignition system problem. A common malfunction results froma tiny pinhole or crack caused by an engine backfire. THis allows gas to enter the crankcase and wet-foul the spark plug at idle speeds and stalling at low speeds. The problem disappears at highers speeds. I am definitely NOT a mechanic, but this info comes right out of the manual. I hope it helps.
 
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