Buick V6 OMC Stringer combo WOT RPM?

Hello.

Today was the first time it was calm enough to really open the boat up. As I was boogying along on plane, I glanced down at the tachometer, and it was almost at 6000 rpms! And that wasn't even WOT!

Is this normal? I immediately backed off just to be safe. To be honest, it didn't sound like the engine was actually spinning that fast, so the first thing I want to do is check the tach.

The engine is a 71 Buick V6 mated to an OMC Stringer drive.

Unfortunately, I don't know what prop I have, I'm new to boating (but not to engines) and wouldn't know where to look.


Also, on an unrelated note, when I throttle back, the drive disengages a little too soon, like maybe 1500-1750 rpms. It engages normally when I put it in gear and accelerate.

Thanks for any help you can offer.

Re: Buick V6 OMC Stringer combo WOT RPM?

I think you have a tach problem. That engine would probably grenade, under load, at 6k rpm. Also you ought to be able to audibly discern between idle speeds of 5-800 rpm and 1500-1750 rpms.

Tachs are goofy critters. There are all kinds of questions regarding the accuracy of them. If yours is as old as your drive/engine combo it is probably toast. Older tachs were analog. Who knows what goes wrong when they go nuts. No one repairs them, even original manufacturers, so you are relegated to replacing it with an equally goofy digital tach.

That being said, I assume that your maximum rpm range is similar to other motors, ie 42-4600 rpm. Idle rpm for your electric shift is a pretty low 550 ish.

Re: Buick V6 OMC Stringer combo WOT RPM?

you could lay on your back and look at the back of the tach, should have a switch for 4-6-8 cylinders, Cycle the switch back and forth and set it to 6.

See if that fixs the problem.

Re: Buick V6 OMC Stringer combo WOT RPM?

Thanks, I'll check it out tomorrow when I'm at the boat again.