Trim Affecting Tach and Performance

[Hydrodreams]

A27 was only ever sold on a 150, 200 and 225 promax. the A19 cam on just about everything from 135 to 225...including some 150, 200 and 225 promax motors.

Seems the A19 will work on everything.

Ok thank you sir, I know they looked very similar and I thought I saw them associated with a ProMax at one point in time. I may give her a try.

[Motv18]

I would test the diodes scr in the switch box, and look at the stator good for goo comming out or burn look on the high side.

what’s the high side voltage at idle?

those are the common high speed miss items. The tach thing might be natural from lost rpm. We forgot to ask how much it flutters 100 rpm 500 1000 ect or just go wack.

[Hydrodreams]

I would test the diodes scr in the switch box, and look at the stator good for goo comming out or burn look on the high side.

what’s the high side voltage at idle?

those are the common high speed miss items. The tach thing might be natural from lost rpm. We forgot to ask how much it flutters 100 rpm 500 1000 ect or just go wack.

The switch boxes are new I even rotated a third new one in just to make sure they were good. The stator still looks new. The tach fluctuates from about 200-500 rpm. If I move the trim switch it's as steady as a statue and accurate. I have a video but I cannot get it to post on here.

[Motv18]

That would lean me to the weak spark condition that has ben mentioned.

is it both up and down trim. If not flip the solenoids see if it follows. You can also do an amp draw on the trim pump.

and back to scrubbing connections.

ahh the fun of electric hunt and peck.

[Hydrodreams]

Found it...well sorta...I had a local tech come over. Turns out its a bad ground and key switch in the boat harness. So here is my new winter project, all new wiring in the boat.

[kbahus]

Any ideas on how the tech was able to isolate the harness/key switch?

[Hydrodreams]

Any ideas on how the tech was able to isolate the harness/key switch?

He bypassed my harness with his own and hooked directly to only what was needed. Then isolated and tested my old switch. My old boat harness is a messed up nest of old wires, after 23 years of splices and the former owner adding different electronics. That's why I just decided to replace the whole wiring system and make it nice and neat. As opposed to more splicings and connections.

[25two.stroke]

Glad you found it!

[kbahus]

Thanks for the update, definitely something different to consider as these boats age. The harness does not seem as expensive as some other Merc electrical items either.

[Hydrodreams]

Glad you found it!

Me too, and thank you for your help.

[Hydrodreams]

Thanks for the update, definitely something different to consider as these boats age. The harness does not seem as expensive as some other Merc electrical items either.

Yes sir, much easier for me to replace the whole thing vs splicing in a new switch. Plus this ole gal doesn't need anymore splices and wire connectors. I decided to rewire the whole boat. Making it nice and clean, more reliable, and safer as well.

[Motv18]

Yep awesome

so many of us know it’s the switch and just want it to be something else to look cool.

[Hydrodreams]

Yep awesome

so many of us know it’s the switch and just want it to be something else to look cool.

HA HA! That's about right Motv, thanks for your help.

[SWA91]

Found it...well sorta...I had a local tech come over. Turns out its a bad ground and key switch in the boat harness. So here is my new winter project, all new wiring in the boat.

Im having this EXACT same issue, although mine tops out at 4200 rpm. Was the grounding and key switch the final fix? Is there a way to test this without having to swap the harness? Burned up two regulated rectifiers already.

[rprinzo]

so did you run the boat on the water and all is well?or just run tests