Rev limiter need more pitch?

[Ballast]

My 55 commercial seems to have the same issue, it’s running the same prop. Once past 3/4 throttle seems like it’s missing, then at wot a rhythmic constant “wa wa wa wa” accompanied by simultaneous side to side shaking. No tach but I’m hoping it’s the rev limiter. Might just have to take a chance, trying more pitch.

 

[Ballast]

1993 Evinrude 55 hp commercial runs great until about 3/4 throttle seems to start missing every 5-10 seconds. Continuing to wot a rhythmic and constant “wa wa wa wa”, with simultaneous side to side shaking. The prop is 13.75x15, and I’m without a tach. Is this behavior indicative a hitting the rev limiter, I’m unable to scrounge a difinative answer after hours of searching. Thanks!

 

[Chinewalker]

Unless you're running it on a super lightweight boat or severely underpropped, I'd guess you're not hitting the limiter at 3/4 throttle. Unless the pack is bad, as that's where the limiter would reside. I might start by looking for a break in a wire, particularly any of the wires that move when the timing is advanced. Also, maybe run the motor with the cowling off and note whether you hear any "snapping" sounds of arcing.

 

[ahicks]

I had a similar problem with a 40hp. After MUCH (much!!!!) screwing around, I discovered the last guy that handed me a set of new plugs had given me non-resistor plugs, and silly me, I didn't notice. They were scattering so much RF under the hood that once past a certain rpm, the engine acted like it had a rev limiter - doing the same thing you guys are talking about. That only took me a month or so to figure out.....

 

[Sea Rider]

Being a 25 year old prop would start by performing a hub slip test, probably prop is already shot. If not, check what's been advised.

Happy Boating