1982 johnson 90hp won't start

[natecollins]

I can't get this motor to start. I checked compression in the cylinders, starting from the top right cylinder (when looking at the spark plug side) and working clockwise: 100 psi, 35 psi, 100 psi, 110 psi. I checked the spark on each of these in the same order: somewhat weak spark, good spark, good spark, somewhat weak spark. Fuel pump seems to be working. Electric choke seems to be working. I played with the manual/automatic lever on this some. Can you tell me what position this lever is supposed to be in for each mode? I opened the carbs and they seem to be clean. I removed the top carb, and I put a rag soaked in gas/oil mixture over the opening where the top double barrel carb goes. When I cranked the motor it appeared to then be starting. I pulled the rag away and it died out. I put the rag there again and tried to start, and it seemed to start again. Can you tell me where the problem could be?<br /><br />Thanks,<br />Nate

 

[JB]

Re: 1982 johnson 90hp won't start

Howdy, Nate.<br /><br />Welcome aboard. <br /><br />Go to the Engine FAQs and do the troubleshooting in "Outboard wont start".<br /><br />Think you will find a fuel or fuel supply problem.<br /><br />Let us know what you find, and good luck.

 

[red boat]

Re: 1982 johnson 90hp won't start

Nate, the problem is the 35psi cylinder more than likely a scored cylinder and time for a rebuild. cylinder compression should not vary by more than 15%. sorry rebuilds suck and cost $$$$$!

 

[natecollins]

Re: 1982 johnson 90hp won't start

Thanks for the comments, but the fuel pump is pumping when the motor is being cranked. I also verified that the electric primer/choke unit is actually pumping gas into the carbs when trying to start (shouldn't this eliminate a gas flow problem? Also, the motor starts to run when I put a rag soaked with gas over the opening where the top carb was screwed on. This should eliminate the idea that the low compression lower cylinder is keeping this from running, right?<br /><br />Thanks,<br />Nate