speed limiter or rev limiter

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bspeednut

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Mar 12, 2010
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I have a 1990 larson senza 210 with volvo penta 5.7
it has a lil black box called a speed limiter back by the engine. I was wondering how i find out what speed this box is set to limit the engine to?
I cannot find it anywhere in the books that came with the boat.
I have upgraded the engine to a newer vortec roller style engine and it only turns 4800 rpm. The boat runs close to 60 but if the engine will turn 5500 - i want it to turn 5500 - Does anyone know anything about this speed limiter???
 

Philster

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Re: speed limiter or rev limiter

You upgraded the engine and it uses the same electronics from the previous engine? Really?

What is the manufacturers RPM redline on the CURRENT engine? Do you know that number?

It might run to 5500 RPMs, but redline might be 4800-5200.
 

bspeednut

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Mar 12, 2010
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Re: speed limiter or rev limiter

yes i upgraded the engine.
The 1990 engine was a 2 bolt main - non roller cam engine from factory
I intsalled a vortec engine with Ramjet Rollercam and vortec heads - Basicly a 1997 longblock with ramjet cam and used retrofit intake to go from vortec heads to the carb. Used same ignition system and sensors and guages. _ so the cam is diff as well as now having vortec heads and 4bolt main lower end. This engine is very similar to the opne i use in my Modified Dirt trac car with exception that this one has a somewhat smaller lift cam and it runs on gas instead of ALKY. I turn that engine 7000 all night long in a 30 lap feature. I dont want to turn this boat over 55 but it seems to stop at 4800 for some reason- I did read that the factory wot was 4800. The cam specs on this cam are good for 5500rpm and the engine is more than capable of handling this i should think.
 

QC

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Mar 22, 2005
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Re: speed limiter or rev limiter

I dont want to turn this boat over 55 but it seems to stop at 4800 for some reason
If it was hitting the rev limiter you'd hear it. Not sure what this "speed limiter" deal is . . . Picture?

The cam specs on this cam are good for 5500rpm
I hope this cam was selected with reversion in mind ;)

the engine is more than capable of handling this i should think.
That's speculation. Can you get us your drive model, prop pitch, gear ratio and how'd you get the speed? GPS?
 

John_S

Rear Admiral
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Jun 21, 2004
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4,269
Re: speed limiter or rev limiter

Don't know Volvos, but Mercs are 200rpm over max and not adjustable. I agree with QC you should be able to tell if it is hitting the limiter. It sounds like that is all the motor is going to spin with your combination. Do you have a lower pitched prop to try?

PS: I think the ramjet cam is the same as the merc roller.
 

cooter2506

Senior Chief Petty Officer
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Apr 8, 2007
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733
Re: speed limiter or rev limiter

Your engine may be able to handle the 5500 rpm but your outdrive may not!
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
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Re: speed limiter or rev limiter

If it's the little black box that Volvo used for a couple of years, disconnect the 3 wires and throw it away. I thought all of those died years ago.
 

bspeednut

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Re: speed limiter or rev limiter

well after further testing and getting the gear ratio and finding out what the outdrive would handle i did as was suggested and threw the lil black box in the garbage. I dont know if it was faulty but as i was going across the lake the engine would slowly lose rpm - it finaly got to where 4500 was max. i tried everything - then i disconnected the lil black box that said speed limiter and the boat was as though i had just shot it with nitrous.
Wow
I will have to get an msd rev limiter though - the boat runs well over 60 now and its turning right at 5500 - im happy with that. - I will be installing an MSD soft touch rev limiter just for peace of mind and mainly bc i have it laying on the shelf from a racecar i bought and parted out. I have heard horror storys of guys not using rev limiter and hit something to sheer the prop and the engine just overrevs too fast for them to react and it blows up. so i think a 5600 chis int hte limiter will do fine.
I rarely rn it that hard but if i decide to i would like to be able to.
 

krazykatz911

Petty Officer 2nd Class
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Aug 21, 2010
Messages
123
Re: speed limiter or rev limiter

Does anyone know if a 2005 Volvo Penta 4.3 GL (CARB) has a rev limiter stock? And if not, can one be installed? I think max RPM on this motor is 4800?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: speed limiter or rev limiter

First off, welcom to iboats.
You need to start a new thread with your question, not at the end of someone elses thread with a completely different question and engine.
 
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