1979 johnson 115 low power, will not get up on plane

[davidmammoth]

I just bought this boat and motor. Has been sitting for 1 year with old gas. I changed the old fuel and oil mix with fresh fuel, also replaced the old spark plugs and gapped to .040.<br />Out on the water it idled fine. I then proceded with throttle and it began to miss/hesitate a little until about 1/3 of the throttle. I then roceded to w.o.t. and the boat woulf not get up on plane and had little power. Peak rpm was only 2700. Frustrated I began trying to find the problem. With my garden hose connected it runs good, only sometimes when I snap the throttle will it hesitate. I checked compression and it was 120 120 115 95. I pulled the spark plugs and found two to be wet and black. I checked spark and found spark. Please someone, what am I missing, Can someone help me? the model # 79tl115r

 

[Badfingers]

Re: 1979 johnson 115 low power, will not get up on plane

I had problem like this. It would just Idle I replace the Top shift cable, Not saying this is it can u check it.

 

[Solittle]

Re: 1979 johnson 115 low power, will not get up on plane

You will find the answere to your problem here:<br /><br /> http://www.outboardrepairs.com/carburetors/

 

[davidmammoth]

Re: 1979 johnson 115 low power, will not get up on plane

Thank you all for your advice. I double checked the ignition system and found that I no longer had spark on half the motor. I tested a known good power pack on that side and it worked great. I replaced the power pack and took it out on the water today. Problem solved, plenty of power ang go fast. Thank You..........

 

[Hooty]

Re: 1979 johnson 115 low power, will not get up on plane

Glab to hear that David. Thanks for letting us know the outcome.<br /><br />c/6<br /><br />Hooty

 

[Hemlock]

Re: 1979 johnson 115 low power, will not get up on plane

Just out of curiousity, how complicated and expensive is replacing a power pack?

 

[davidmammoth]

Re: 1979 johnson 115 low power, will not get up on plane

Replacing a power pack on my outboard was a very simple job. It took about 5 minutes and 3 bolts to rermove and reinstall. The connectors were simple to reconnect as well. Piece of cake!!! Also a new power pack was $90.00 Hope this helps.....

 

[Cricket Too]

Re: 1979 johnson 115 low power, will not get up on plane

davidmammoth......I would keep my eye on that one cylinder that has the lower compression, whatever caused it could keep making it worse if not corrected.

 

[Hooty]

Re: 1979 johnson 115 low power, will not get up on plane

Mikes right. You may want to do a decarb and see if the compression comes up. Use the search function and look for "decarb". That'll explain it all to ya.<br /><br />c/6<br /><br />Hooty