RPM's going high.....90hr Evinrude

[Jmorrell588]

1989 90hp crossflow V-4<br /><br /> My RPM's at max is right about 4,900. It was hitting 4,900 today until I went back to the ramp. I noticed that it was at 5,700 RPM's at full throttle. What caused (best guess is all I am looking for) this happen and is this something I should worry about? Thanks for your time.

 

[mrtool2u]

Re: RPM's going high.....90hr Evinrude

Did you happen to lose a blade on the prop,,,,,I lost a blade once and I gained a few hundred rpm's,,,just a thought.

 

[Jmorrell588]

Re: RPM's going high.....90hr Evinrude

MrTool... no that was the first thing I checked. I also checked the hub to insure it was not spinning by starting off from low speed in the water and going to high speed real fast... hub is fine.

 

[Dhadley]

Re: RPM's going high.....90hr Evinrude

One good thing is -- thats a lot closer to where the rpms should be. Did you gain any speed? Lose any speed? <br /><br />Lets start here. Good luck!

 

[jim dozier]

Re: RPM's going high.....90hr Evinrude

Did the engine sound different. I would think you could hear an additional 1000 rpms. Certainly if the engine speed increased by 1000 rpms there would be a noticeable speed increase. I'm wondering if your tach was the culprit. Ultimately, like Dhadely says, 5700 rpm is closer to correct than 4700 rpm. For how long have you been running the engine at the "apparent" 4700 rpms?