1985 Johnson 50hp runs great with cowel off

[johnewrangler]

I just bought a boat with a 1985 Johnson 50hp. When I bought it I was told the pee hole was (bypassed?)but it ran fine and water was comming from the mid section of the engine. Just wanted to mention that.

I ran it last week for 15-20 mintues with the muffs in my driveway and it ran fine. Today I took it out and at first it ran like crap. I barely made it from the ramp to the dock. I let it run on fast idle for awhile and it still ran bad. I took the engine cover off to see what I could see and it ran great. I shut it off,put the cover back on and it ran bad. Took the cover off and it ran fine again. I left the cover off and took it out. It did pretty good but I was concerned about the wiring getting wet so I only went for a 20 minute ride.

On the way back it did seem to bog down a bit and at times seem to miss fire. I took the cowel apart to see if it was blocking air but it looks fine. Any ideas on what would cause it running so good with the cover off? Thanks!

 

[petryshyn]

Re: 1985 Johnson 50hp runs great with cowel off

sounds like the engine base gasket is leaking exhaust, filling the engine compartment with exhaust gases. This will make it run rough and low power.

 

[tashasdaddy]

Re: 1985 Johnson 50hp runs great with cowel off

agree^^^ not getting oxygen. because exhaust is overwhelming the cowl.

 

[johnewrangler]

Re: 1985 Johnson 50hp runs great with cowel off

Thanks for the info! Do I need to remove the engine or can I come up from below? Also any online instructions you know of would be great.

 

[john200]

Re: 1985 Johnson 50hp runs great with cowel off

also check to see if any wires are coming in contact with the cowel or getting pinched or pressed against any thing with the coweling on

 

[tashasdaddy]

Re: 1985 Johnson 50hp runs great with cowel off

he has an exhaust leak, you need the OEM Johnson manual, outboardbooks.com or ebay.

 

[daselbee]

Re: 1985 Johnson 50hp runs great with cowel off

Thanks for the info! Do I need to remove the engine or can I come up from below? Also any online instructions you know of would be great.

Yes, to answer your question directly, you have to remove the powerhead to fix the powerhead to exhaust adapter gasket.

 

[johnewrangler]

Re: 1985 Johnson 50hp runs great with cowel off

OK here is where I am at. I removed the lower cowel cover and ran the engine in my driveway to find the exhaust leak. I covered the exhaust comming out the hub and found no leaks at the base/spacer gaskets or plate.
The pee hole for the water has no hose going to it and after running around 5 minutes I heard a buzzing noise from the shift lever area. I shut the engine off and turned the key on to hear and alarm that I assume is the engine over heating warning. I did have the top engine cover off when I ran it but found no signs or exhaust leaking from the base area. The engine did run rough while I had the exhaust blocked but did not stall.
Any ideas on what I should be looking for next?

 

[johnewrangler]

Re: 1985 Johnson 50hp runs great with cowel off

Well I found a few things. The exhaust was leaking at the lower end gasket. The grommet for the pipe to water pump was missing. The water pump lookes new.

I put the covers back on and ran it fot 20 minutes and it did fine. I ams till a bit concerned about the pee hole being bypassed. Does anyone know where the water comes out of the engine? I just have the nipple on the pee hole no hose. Thanks!