Evinrude 25 wot timing issue? surging

1993 evinrude 25 that was converted to 35 is surging above just over 1/2 throttle.the cam plate is moving back and forth causing my timing to advance which is causing the surge.if push and advance the timing myself it will stop surging and boat will rev up and run great.i get 4700 rpm then surge kicks in but if i hold and advance timing myself i can go to 5600.i dont try to advance any further than this while driveing.can you guys tell me why its jumping?ill attach a pic so you can see cam im talking about.i dont have video of it surging.

Oki believe its called the timer base.what makes this work?or could it be dirty and causing it too stick and release causing the surge.?anybody know about these?

Should be a linkage hooked up to the throttle somewhere.

I can give it throttle and works great up to half throttle.my problem is the timing no lomger advances after half throttle.its like its stuck then all of a sudden it will advance and then retard.which is causing the surge.if i advance it by hand then itll rec up up and run good and speed picks up like it should.just cant figure out why the timing will advance and then retard repeatedly

Issue is fixed.sprayed wd40 under flrwheel and on throttle cables and freed everything up up and this allowed my timing to advance as it should.i then adjusted my timing to 30 as it was low.lubrication was the fix here.

That's a great thing to read.
I'm glad you got'r fixed easily.
I, and a crapload of others(hopefully [emoji51]) will read n have hopes to solve same way...
Otherwise....
You'll get a lot of private messages!

But yeh...
Glad ya got it figured out n thx for sharing it.

Adam


Sent from my iPhone using Tapatalk

Joshsmith2005 said:

Issue is fixed.sprayed wd40 under flrwheel and on throttle cables and freed everything up up and this allowed my timing to advance as it should.i then adjusted my timing to 30 as it was low.lubrication was the fix here.

Click to expand...

Do you know specifically what was getting stuck under the flywheel?

Also note - WD40 is not a lubricant. It's a water dispersal fluid so when it dries up your symptoms may reappear. IF you know what the problem was, I'd suggest lubing with a true lubricant.

CMOS

WD40 makes a silicone spray that is handy for stuff like that.