75 15hp ?

20/20

Petty Officer 2nd Class
Joined
Jun 29, 2004
Messages
173
I have a 15hp evinrude that does not want to run over 1/4, 1/2 throttle. Will plugs help, and what other adjustments should I be looking at?
 

K Hultgre

Petty Officer 1st Class
Joined
Jul 28, 2003
Messages
306
Re: 75 15hp ?

Need more info.<br />does it rev up and the boat does not go faster?<br />does it bog down?<br />does it sputter above 1/2 throttle?<br />Salt or Fresh Water?<br />Any work done to it previously ?
 

the machinist

Senior Chief Petty Officer
Joined
May 7, 2002
Messages
711
Re: 75 15hp ?

My guess is that you twist grip throttle gears have jumped a cog. This is because you raised the handle & twisted the throttle. If this happens the motor will start, & run but not over about 1/2 throttle since the grip can't go as far as it needs to.
 

20/20

Petty Officer 2nd Class
Joined
Jun 29, 2004
Messages
173
Re: 75 15hp ?

Originally posted by Kevin H.:<br /> Need more info.<br />does it rev up and the boat does not go faster?<br />does it bog down?<br />does it sputter above 1/2 throttle?<br />Salt or Fresh Water?<br />Any work done to it previously ?
{1}It's 15504c 1975 15hp has not been run in a few years{or atleast that is what I was told}.<br /> <br />{2}Have not had it on the lake yet still going through it to make sure things are up to par. parts I've changed, impeller, new bottom end seal kit, new head gasket, points con. plugs, acouple other odds and ends.<br /> <br />{3}didn't bog down, but I've only been running it in a 55gal tank. Runs rough, revs up holds for awhile then started running rough again. adjusting carb while running would only help some times, then other times didn't seem to have an effect.<br /> <br />{4}didn't really sputter more or less just didn't want to stay smooth.<br /> <br />{5}fresh water, not sure of where it was ran before, more then likely fresh water.<br /> <br />{6}see {2}<br /> <br />Took the carb apart yesterday, gaskets didn't seem to be that good{waiting for the kit to come in}. Also noticed a small hole in gas line. I'm hoping this is the problem, is there anything else I should watch for while I have it torn apart? What is a good starting point for the needle adjustment{I've heard anywhere from 3/4 too 1&1/4 too 1&1/2}? Thanks for the help.......
 

20/20

Petty Officer 2nd Class
Joined
Jun 29, 2004
Messages
173
Re: 75 15hp ?

Originally posted by the machinist:<br /> My guess is that you twist grip throttle gears have jumped a cog. This is because you raised the handle & twisted the throttle. If this happens the motor will start, & run but not over about 1/2 throttle since the grip can't go as far as it needs to.
Thanks, but the throttle seems to be in fair to good shape, it does open all the way up. I'm hoping I found the problem between the bad gas line and old carb gaskets. Anything else I need to look at?
 
Top