Does the switch box impact the rev limiter?

[Chris1956]

Gee, worse comes to worse, be your own rev limiter, and D/C that black box.

 

[richw46]

Agreed, if there's no other way. I was surprised when I was running down the lake and trimmed up a little bit to see if I could get more speed out of it. It started to cavitate and the RPMs jumped up to 5400 so I dropped it back down. There is a feature, and perhaps that's the rev limiter + switch box, that is supposed to prevent your engine from trimming up too high once you reach a certain RPM. 5400 isn't that much higher than 5250 but I don't know where "too much" is. The tach redlines at 6000 and I've never seen it go past 5300 before with the limiter engaged.

I'm just happy it's running that well again. Riding around on the trolling motor this past fishing trip with my friends was a real downer.

 

[Chris1956]

Gee, if the RPMs exceed redline, a prop with more pitch may be in order. It can improve fuel economy and maybe top speed.

 

[richw46]

Gee, if the RPMs exceed redline, a prop with more pitch may be in order. It can improve fuel economy and maybe top speed.

The tach redlines at 6000, but it's just a tach. My motor has never been beyond 5400 and reached that only when it was cavitating. Normal max RPM is 5200-5300, which is the spec for the motor.

 

[flyingscott]

5250 is tops for that motor. Anything above 5500 you risk broken piston skirts. Like I said thevrev limiter is normally on the jets not the props.

 

[richw46]

I put the OEM switch box back on the motor and it behaves like the new CDI box, which means it's the rev limiter that's maxing out at 5000, but I wouldn't it to fall on its face, just stop any further acceleration. The motor runs fine with the rev limiter black w/yellow stripe disconnected. I'm happy to be back on the water. Thanks for everyone's feedback.

 

[richw46]

I put the OEM switch box back on and reconnected the 3 year old rev limiter. It stalled at 5000 RPM. I told the vendor it's not the switch box since behavior is the same for old and new. I bought another rev limiter and tried it out today; same thing. It stalls at 5,000 RPM ($104 down the tubes). My service manual says the brown wire on the rev limiter is the RPM from the trigger. Both are connected to the switchbox on the same post.

At this point I don't have a solution, nor do I know of any way to find one. The tach gets its feed from the voltage regulator, fed by the stator coil, and the rev limiter gets its feed from the trigger coil. Trigger coil tests are spot on according to the service manual and the stator is brand new. I disconnected the rev limiter and the motor goes up to 1200 rpm (peak HP level in the specs) and stays there. Since some of these models don't even have a rev limiter I'm tempted to just leave it disconnected and not worry about it. It will eat at me, however.

 

[Dukedog]

jfyi... most guys with years of experience with these v6's float test all tha modules/ rpm, idle boxes/oiler junk with any motor they don't have a personal back ground of its history.. it eliminates any problems that they can and will cause.. it does absolutely nothing ta harm tha motor.. they are expensive (as ya found out) and really have no benefit.................... jmo