1991 Johnson 60 HP won't run in water

[chevy91174]

I recently bought a 91 Johnson 60 HP on a 17' Bass Tracker that hasn't been in the water in at least 3 years. Compression checks out at 115 to 120 PSI across all cylinders. I have replaced spark plugs, power pack, rectifier, primer solenoid, and tank fuel lines. Cleaned gas tank, carbs, and fuel pump (VRO oil pump had already been deleted and lines plugged). I sync'd throttle plates, adjusted linkages, and set timing by the manual. Filled gas tank with 50:1 fuel/oil. Set timing at 2 ATDC at idle (700 RPM). Out of the water (with water hose attachment), the engine starts pretty good after initial priming and throttle response is good. Timing advances as expected while in gear in forward and reverse. WOT seems good, although my RPM gauge does not currently work. Water indicator good and temp seems OK to touch, but don't have a way to verify for sure. When I launch the boat in the water everything goes south. Today I let it idle in the water for about 5 mins then pushed off and it died as soon as I put it in gear. Tried multiple times and even after adjusting the idle higher, it would still die almost every time. Tried disconnecting temperature switch, but no change. When it did stay running, it bogged down pretty bad. Back at the house, it ran fine again out of the water. Plugs were not fouled. At a loss here. Bad fuel Pump? Bad stator or timing base? Anybody had similar experience? Sorry for the long post, just trying to cover all I've done.

 

[WernerF]

Idle rpm must be adjusted in the water in gear. If everything is in excellent shape 700 rpm will work. Some motors need 800 in order to stay running. Correctly adjusted the engine will idle about 1000 in neutral and 1200 on the hose.

You might have one cylinder not firing, at least at idle. On the hose those motors sound pretty good on just two cylinders.

 

[sutor623]

Idle rpm must be adjusted in the water in gear. If everything is in excellent shape 700 rpm will work. Some motors need 800 in order to stay running. Correctly adjusted the engine will idle about 1000 in neutral and 1200 on the hose.

You might have one cylinder not firing, at least at idle. On the hose those motors sound pretty good on just two cylinders.

Good advice right here, and certainly where I would start. Once you get the RPMs right do a spark drop test. Pull each spark plug one at a time while the engine is running at idle and see if the engine stumbles. If it stumbles or shuts off, that cylinder is good to go. If it acts like nothing happened, you have spark issues at that cylinder.

 

[chevy91174]

Gonna try troubleshooting the spark tonite and see if I can get the idle up on the hose. I wanna try and get this thing running as close as I can before putting it back in the water for final tuning. Good to know I'm looking for quite a bit more idle on the hose. Thanks to both of you for the insight. Will post results later. Thanks again!!!