What happened?

cakustoms

Recruit
Joined
May 31, 2009
Messages
3
'86 Johnson 120 v4 Last year the motor didn't have much off the bottom and when it hit top end it would surge a little, I could back it off just a little and it ran pretty good. This year I started it on muffs and it fired right up but it runs really rough. I noticed that the 2-4 bank was running hotter than the 1-3. I checked to make sure all cylinders were firing, they all were. I decided to check timing with a light while it was running, so I throttled it up to full and got around 32* it's supposed to be at 22*, so I backed off the throttle till it was at 22* and after a couple of seconds it acted like it was gonna die and then it picked back up and ran so smooth I could barely feel it in the boat and the timing was dead on. It ran that way for about 2 minutes till it ran out of fuel and I haven't had a chance to run it again.
The questions are---- why was the timing off so far? what happened to get it smoothed out? Did the fuel lean out and it ran better till it ran out? The oil side of the pump is disconnected and I'm running 50:1 mix, new plugs, fresh gas.
Any ideas would be great. This motor has always been very strong.

P.S. I also checked compression--- 120,118,115,110 within the 10% but it's close.
 

basbalj288

Petty Officer 3rd Class
Joined
Jul 17, 2009
Messages
88
Re: What happened?

I just recently reset the timing of my 85hp Johnson because it was off about 8 degrees at WOT and after doing so it ran beautifully so I'm not sure if somebody tinkered with the timing advance but I don't think you should worry too much about why it came out of whack as long as you readjust it and make sure its the advance bolt is locked in good once its set. That's just my suggestion though but it definitely needs to be set where it's supposed to or else it can cause some serious engine damage
 
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