1977 johnson 70 hp

[mdt8]

motor seems to run fine when setting in yard but when put in water under load .motor will barely push boat. when i take the spark plug wire off bottom plug nothing seems to change. could this be a carb. problem.

 

[almost retired again]

Re: 1977 johnson 70 hp

HI MTD8,<br />It sounds like it might be that you are not getting spark to that cyl. Do a compression check and a spark check on all cyl.s, let us know what you find and get back to us.

 

[Chinewalker]

Re: 1977 johnson 70 hp

It could indeed be a carb problem - if ARA's suggestions don't show a problem, go through the carbs and make sure they're spotless! Carb kits are readily available over the counter at an OMC dealer or next day through a NAPA dealer. Don't run it again until you get it sorted out, as a plugged up carb isn't giving that cylinder fuel/oil mix and it could be running dry.<br />- Scott

 

[mdt8]

Re: 1977 johnson 70 hp

THANKS GUYS,I DID CHECK THE COMPRESSION AND I WAS GETTING ABOUT 120# OF PRESSURE. I PULL OUT THE PLUG AND WAS GETTING A SPARK, SO I AM CONFUSED AS TO WHY IT DOES NOT CHANGE WHEN THE PLUG WIRE IS REMOVED.

 

[Franki]

Re: 1977 johnson 70 hp

well, if you have a spark, and you have compression, I'd not be running your motor too much till you find out why.. if you have a carb blockage on that cyl, then running it will be bad cos there won't be alot of oil, (if any) getting into the bore to lube it..<br /><br />First thing I'd do is get a squirt bottle of premix and spray it down that carb throat while running and see if it picks up.. if it does, then the carb has a blockage.<br /><br />strip the carb in question and give it a clean out..<br /><br />regards<br /><br />Frank

 

[mdt8]

Re: 1977 johnson 70 hp

I DID INDEED REMOVE THE BOTTOM CARB. AND GAVE A GOOD CLEANING. KNOW EVERYING THING SEEMS TO BE RUNNING JUST FINE. I APPREA. EVERYTHING YALL HAVE DONE AND WILL CONTINUE TO USE THIS AS IT IS VERY HELPFULL. THANKS MIKE,FROM HOUSTON