Johnson 70HP Starts But Won't Go!!!

DawnPatrol

Recruit
Joined
May 27, 2002
Messages
3
Dear Experts,<br /><br />I have a Johnson 70hp outboard, not sure of the year. Model # J70TLCCA. It's been running great as of late. I took it out a couple of days ago, and it started up on first crank and idled fine for about 10 minutes before I tried to leave the dock. When I put it in gear it staled out. It restarted fine, but staled each time I tried to put it in gear. In neutral it runs fine, can rev it up and it sounds great. I changed the spark plugs thinking they could be fouled out and I tried running it again. This time it would run in gear, but barely. At wide open it was barely pushing the boat. It still started up on first crank, idled perfect, and it worked in reverse too. But when in gear it will barely move forward, about less than trolling speed. It has new plugs, and the gas was filled new that day. I really don't know what it could be other than it just didn't feel like going fishing that day. I took it out the week before and it ran perfect for 20 miles in the bay and gulf. If anyone can help please let me know your thoughts. Thanks ~ J
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: Johnson 70HP Starts But Won't Go!!!

The engine is a 1988 70hp Johnson.<br /><br />Regardless of the problem, always start with the basics. Check the compression, should be 100+ psi and even on all cylinders.<br /><br />Rig up some kind of spark tester and set a gap of 7/16". The spark should jump that gap with a strong blue lightning like flame on all cylinders.<br /><br />If the above checks out okay, the usual cause is fouled carburetors, in which case they would require cleaning and rebuilding. Let us know what you find.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: Johnson 70HP Starts But Won't Go!!!

I'm with Joe - and DON'T RUN THE MOTOR ANYMORE until you get the problem solved. Continuing to run the motor with one or more gummed up carbs can result in the associated cylinders being run without lubircation. OMC's VRO mixes the oil with the fuel before the carburetor circuits, so a fouled carb won't feed fuel-oil to it's cylinder(s).<br /><br />Pull te carbs off and go through each one, paying special attention to the carb jets and passages... A manual would be a wise investment.<br /><br />- Scott
 
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