Evinrude dying at 2500rpm

[djandjas]

Have an 1972 125HP evinrude (Model #125283R ). Generally starts ok (can be a dog some days ) but have a persistant problem with the motor stopping whilst under load at about 2500-2700rpm. <br /><br />-Gently accelerating from idle and it will die each time it hits the 2500-2700RPM mark<br />-When in neutral its not a problem.<br />-You can "Blast" straight past the problem revs by opening the trottle quickly. <br />-9 times in 10 the motor starts instantly again.<br /><br />Have put in new plugs and run a carby cleaner through it.

 

[rickdb1boat]

Re: Evinrude dying at 2500rpm

Jas,<br />Does it die like the key was switched off, or does it stumble and die? That's important in determining if it's a fuel related or electrical problem. It sounds like right off the bat that you need to pull the Carbs down and rebuild them, as the floats/needles may be sticking partially, causing your hesitation and dying problem. This is also indicated by the intermittent hard starting problem. Also be sure that the timing plate is moving smoothly when the throttle is advanced.

 

[one more cast]

Re: Evinrude dying at 2500rpm

Just a hunch, but it sounds to me like you have a bare wire that is shorting out on the backing plate. With the motor in netural you would hit the same revs at a different throttle position,not showing the problem.Try Removing the hood and have someone run the throttle with the motor off and see if you can find a spot where the backing plate rubs on a wire.Good luck

 

[Joe Reeves]

Re: Evinrude dying at 2500rpm

Jas.... That problem can be caused by a few different problems such as:<br /><br />1 - The timer base under the flywheel is sticking, causeing the spark to be retarded.<br /><br />2 - The wires leading from the timer base to the p/pack may have a frayed break in one of them. Can be checked with an ohm meter (wiggle the wires).<br /><br />3 - The throttle is opening too soon in relation to the timing. Throttle should just start to open when the scribe mark on the cam aligns with the center of the throttle butterfly roller.<br /><br />4 - The carburetor(s) are somewhat clogged/fouled, in which case the cure would be to remove, clean, and rebuild them.<br /><br />THere may be other reasons but the above are the most likely.

 

[djandjas]

Re: Evinrude dying at 2500rpm

rickdb1boat : Stumbles and dies. If you are really quick and back the trottle off you can save it

 

[rickdb1boat]

Re: Evinrude dying at 2500rpm

Jas,<br />Check # 1 And #3 that Joe posted above. Timer Base moving freely and lync & sync of the Carbs. If those are OK, rebuild the Carbs.