rev limiter on a 88' 88spl

[Rancherlee]

Just picked up a 88' 88spl yesterday and mounted it on my boat today. The guy I bought it from had it on an 17' cuddy which ran 32mph on gps with it. He gave me a spare prop and both props are 13.5x17 and I think there probibly too short of a pitch for my boat as I should get 40mph+ out of my boat with this engine (I got 32mph out of a crank rated 55hp). Where does the rev limter kick in and is it ok to run it up against the rev limiter for a short period of time (like long enough to check the tach quick and back the throttle down) as I'd like to verify my tach on the 12 pole setting (my 55hp was is a 10 pole). Also I assume that I should be shooting for a 5800rpm WOT speed like the rest of the crossflow motors?

 

[imported_lorin]

Re: rev limiter on a 88' 88spl

I don't believe the 88hp (nor the 85 hp) has an rpm limiter. The 4 cylinder cross flow engines with a limiters are the 90hp, 100hp, and 115hp, and I'm not sure if all of the models with those horse powers have a limiter. For those with the limiter, the limit is 5800 rpm. So the rpm limit is above the full throttle operating range which is 4500 to 5500 rpm.

 

[Dhadley]

Re: rev limiter on a 88' 88spl

Take a look at the power pack and see what's written on it. If it's a limiter pack it will have something like "58L" or "6L" on it. If there's nothing like that then it's not a limiting pack. After almost 20 years there's no telling what pack may be on there.

 

[Dhadley]

Re: rev limiter on a 88' 88spl

And don't be afraid of setting it up at 5800. With todays fuel the motor will actually live longer.

 

[Rancherlee]

Re: rev limiter on a 88' 88spl

I'm starting to wonder if these 88/90hp carbs support enough air flow to run at the recommended 5800rpm. I got to put the boat in the water today and give it a test run with 2 different props.

First prop is a 13x17 OMC aluminum and I got 5200rpm out of it with 2 people on board and I hit 38mph on GPS for a 10% prop slip. I know everyone recommends 5800rpm so I grabbed a 13x15 OMC aluminum prop from my friends boat and tossed it on and my RPM's only climbed to 5400rpm and ran at 34.5mph on GPS for a 10% prop slip again. I can't see going to a 13x13 prop to get my rpms up even more and loose even more speed and the engine doesn't seem to be lugging at all with the 13x17 prop as it jumps on plane almost instantly (about 3 seconds) and going from a 3500rpm cruise speed to WOT the tach jumps straight to 5200rpm and stays there.

I really don't want to increase wear n' tear on my engine but am I OK only running 5200rpm with a lighter boat (about 1800lbs with gas, 88hp/6hp, 3 batteries, and 2 guys on board)