15 hp evinrude bogs down

[amelia]

my 15 hp evinrude starts and runs great until about 1/2 hour of run time at high speed. It will bog down to about1/4 speed and eventualy die out after 10 minutes. I just had the thermostat replaced as water was spraying out from the theromstat cover. When I let the engine cool for a few minutes it will start and run fine yet will eventually bog down again. What's up?

 

[Solittle]

Re: 15 hp evinrude bogs down

Sounds likw it is time to replace the water pump. You didn't indicate the year of your motor but if it is an oldie and run in salt water you may also need to clean the water passages in the head and exhaust cover of the salt water crud that builds up over time.

 

[sloopy]

Re: 15 hp evinrude bogs down

HEY try this, next time this happens and starts to slow down squeeze the fuel pump ball, if it is not stiff thats why! in te sun the fail alot and don't stay hard,

 

[amelia]

Re: 15 hp evinrude bogs down

Solittle,<br /><br />when you say water pump do you mean the empellor? I get a fairly steady stream of cooling water coming out of the engine.<br /><br />Sailor,<br />I have tried squeezing the bulb, It doesn't seem to do any good.<br /><br />I have a hunch it could be the spark wires. Is it worth replacing them??

 

[fireman 757]

Re: 15 hp evinrude bogs down

You could have a coil/powerpack overheating and breaking down. Next time it slows pull one of the spark plug wires. If it dies the coil is good if it doesn't change then it is bad. You may need to replace it.

 

[oldboat1]

Re: 15 hp evinrude bogs down

won't hurt to replace the plugs if it has been a while, but doesn't sound like that is likely to be the cause of the problem. Are there signs that the engine is overheating? When it acts up, is the top of the head too hot to touch (an indication that it is running too hot)? I'm assuming that you are running with the right oil mix -- 50:1 for motors produced within the last 30 years or so.