View Full Version : Rev limiter
09-13-2012, 03:22 PM
Anyone have any experience with the rev limiter? I was going across lake last weekend at 90% throttle,(smooth water, 2004 X-Star, zero ballast, a new power prop for surfing), and suddenly the boat felt like it shifted into neutral and over-revved. Engine light and alarm stayed on, after I pulled throttle back to neutral. Turned key off and restarted. No engine light or alarm. Throttled back up again and it did the same thing. Talked to a guy who said it sounded like the rev limiter. I didn't even know the engine had a rev limiter. Never did this before, pryor to replacing prop. Any suggestions.
09-13-2012, 11:35 PM
what was the rev's when this happened, you might have over propped the boat and is bouncing the revs to save the engine...
09-14-2012, 01:25 AM
If the engine over-revs, the rev limiter will cut the fuel/spark to the engine until the revs go below the limit - then it'll turn the fuel/spark back on, the engine will over-rev, and it'll do it all over again, at least on my boat. It's a protection mechanism, and it's generally built into every engine with electronic ignition.
For most normally propped boats, full throttle will take the engine up near, but not up to, the rev limit - unless the prop comes out of the water, you're never going to hit the rev limiter. If you under prop the boat (put too small/too low pitch prop on), you'll be able to hit the rev limiter in the water.
If you've just changed the prop to a "power prop", you've probably done this - you've traded off more power out of the hole for more revs at full throttle, meaning that you can now hit the rev limiter. I did this on my boat - trading the stock 14x20 prop for a 13.5x17.5 (IIRC) prop that gave a lot better power, but at full throttle the engine will get over 5000 RPM and bang off the rev limiter. For me, it's a good tradeoff.
09-14-2012, 01:39 AM
I've never had an alarm or check engine when I hit my rev limiter.
09-14-2012, 09:27 AM
I didn't include the other issues we experienced the weekend before, because I was told the two were not related. I filled the boat (gas) at a location (on land) I had not used before. Took the boat out and towing my son on wakeboard and the boat shut off. It happened three different times before we called it a day. I assumed it was bad gas. (never happened before). I drained the gas and replaced it with new gas. The next trip out, we experienced the over rev, and the boat was still cuuting off. I opened the throttle to burn up any residual bad gas. I don't know what the RPM reached because I immediately throttled back. The lake was very rough the day the initial problem (shutting off at speed), occurred. Could the two be related. Also after I got the boat home, started checking things out. No spark to the plug. Replaced the distributor cap and rotor (very corroded), still no spark. Brand new batteries a month ago. I have a large audio sytem (three different amps Wet Sounds) all wired to the two batteries. Would this have any adverse effects. Thanks for the responses
09-14-2012, 12:09 PM
I have a 2000 5.7 310 hp and max rpm is 5,000. No alarm or check engine light when I hit the limiter, it only feels like it is surging. Nothing extremely noticeable. I am re-propped for 6,000' altitude.