Rev limiter on a Mercury 4 stroke?

[indyboy]

Was wondering if the newer (2000 and newer) Mercury 4 strokes come with some kind of built in rev limiter. If not can one be added? Thanks!

 

[Texasmark]

Drawing a possible parallel to 2 stroke engines, I had an OEM manual on the 3 and 4 cyl somewhat recent engines and in that manual were about 4 different wiring diagrams covering the different models of these engines including manual start, elect. start of 2 types and jet. Some of the harnesses showed rev lims and some didn't. Mine didn't have the limiter but the wiring was there to accept one.

HTH.

 

[bruceb58]

I have a 2006 90HP 4Stroke and the ECM has a rev limiter function. It does it by disabling some of the injectors at 6200RPM and above. My engine is the Yamaha head.

I have an OEM Mercury Service manual. You can look in yours if you have one and it will tell you how it operates.

What engine do you have? If you are carbed, it will be done with the ignition and not with injectors like mine is.

 

[indyboy]

Thanks guys....after talking to several Mercury dealer service departments with no clear answer I came across the national Mercury engine hot-line. They confirmed that their 4 strokes have a rev limiter that kicks in over 6200 RPM. Too bad it's not adjustable.

 

[bruceb58]

Thanks guys....after talking to several Mercury dealer service departments with no clear answer I came across the national Mercury engine hot-line. They confirmed that their 4 strokes have a rev limiter that kicks in over 6200 RPM. Too bad it's not adjustable.

What year engine do you have?

They actually can be changed but you have to have them reprogrammed by a service that works on them. I really can't see a reason why you want to do that.

 

[indyboy]

I haven't purchased it yet. Me and a buddy of mine are looking to purchase a fish and ski boat together and we are considering a 4 stroke. It would be in the mid 2000 year class. I know that Mercury used Yamaha heads until late 2006 and possibly into early 2007. My concern is that my buddy has 2 kids that are in their late teens who will have access to the boat and they are speed demons. Unless the boat is properly propped I am worried they will spin this engine to the max at every opportunity. I remember when I was that age and high speed was king! They also don't have a ton of boating experience and if the motor is trimmed up too high during a high speed turn then cavitation and over-revving can be an issue. Would be great to have a programmable rev-limiter and set it to 4000 RPM when they use it.

 

[schematic]

just limit the max. throttle travel.....