I have a 36 hp Prodrive with less than 150 hours however it was made first year they came out but kept in top shape. Yesterday i was in the river and clipping along around 4000-4100 rpms looking for ducks. Motor just quit! might have sounded like a small back fire. But i got to bank and tied up and could not get it cranked. motor would turn over and over over but never hit or fire Here is where i stand. Any suggestions on what i need to check please. thanks

1. Emergency Cut off safety clip in place
2. plenty of gas
3. fuel pump sucking
4. fuel filter clean
5. can pump bulb and fill filter full of gas

First verify that you are getting spark. Its common for the diode on coils to fail or the ground wire to coils to be grounded. Second there is a fuel shutoff solenoid on bottom of your carb. There is a small connector at solenoid and another connection a few inches above the solenoid. Both of these are common fail points. Check this stuff then report back

Will do thanks! i am just an old plywood salesman but hope i can fix before saturday. May rule out carb since i had Boat Doc do a phase 1 on it last summer.

The solenoid itself can die as well.

so i need to establish Fire or no Fire to plug.

1.If getting fire by pulling plug and checking for fire when i ground plug to metal, then it might be a Kill switch issue or????

2. If not getting fire to plug then it could be
a. bad coil
b. solenoid
c. burnt diode
d.??

when you say boat doc installed phase one does that mean a single carb kit?

Check ur kill switch. This has happened twice to me. Bet the contacts are open.

Check oil pressure sensor, might of went bad.

Checked last night and getting fire to the plug
so...
1. check gas pump?
2.?

Check for power and ground at above mentioned fuel shutoff solenoid. You should also be able to hear it click when key is turned on

hey Guys, thank for the help and suggestions. What i thought was a spark wasnt!! basically no fire to the plugs until i pulled black wire ( emergency cutoff) to coil.. Then check plug and it was firing away. I then order a wiring harness from PD and will replace..

last question.....to take cover off...do i have to take the 3 bolts out also that hold the screen on the engine cover? if so what size is that * star bolt? thanks

T30 IIRC. and while you have it off, Cut the long studs that the screen threaded into. Cut then about the length of a bolt head and toss the grass screen bolts in the garbage. I zip tie the scree to the metal shroud and it keep trash from getting into the fan on a PD.

Got a new harness in from PD however after my stage one, plug was cut out so it is direct wired with no female or male. Ran into Briggs dealer rep accidently in Briggs store and he said it was not my diodes!. i am all screwed up now all i know is if i unplug black wire to back of coil, the plug will fire. questions. anyhelp much appreciated

1. Can i take new wiring harness and cut Diodes out and cut out old diodes and wire new ones back in with electrical tape, etc?

2. If replacing diodes doesnt work, is it saftety switch?

thanks

The wire you are disconnecting is the kill/ ground wire. Do you have a volt meter or test light? That wire must be grounded and turning the coils off. Either the wire is shorted out somewhere, kill switch shorted, oil pressure swich grounded...

does this motor have single carb since you say boat doc installed phase one does his phase one consist of a carb? if so is it non cdi and does it have an external rev limiter? i have seen wiring harness issues were external rev limiter was not getting 12 volt which in turn grounds coils and would not let motor run fire. just a thought you may not even have one thought i would throw it out there.

Hey guys thanks for the help and patience with me, I pull wires off back of coil and turned the key . BAM. It roared like a loin and scared the crap out of me it started so fast. So I have a new harness from PD so I am either going to splice diodes in or wire it back to original plug PD had it. Amazing a little diode as a big as a pencil eraser can shut you down at any moment. But been a great learning experience on how and what to check. Just looking at the diode I think I can preform diode surgery and fit new in wiring of the old instead of replacing whole harness. Anyone ever do this?

RRambler . It's a single carb but it does have rev limiter which you bring up a great point. Can the rev limiter burn The diodes out? Motor has less than 4 hours with rev limiter. But I have owned motor for 10 years and burned last diode the day I got it 10 years ago!! wondwr if I should disconnect rev limiter

What the diodes do is beyond my knowledge. i just know non cdi has them and cdi motors i have worked on never had them. as far as rev limiter burning them up i have no idea either. i have had 3 non cdi motors with external rev limiters and never had a diode problem. and i would not disconnect the rev limiter and put it on the water but you could disconnect it to check and see if it will run with it disconnected

If there was an issue with the rev limiter, it could certainly damage the diodes. They have a wattage rating and, if overpowered, they will fail. I believe the ones on the briggs are only like a 3watt version so it doesn't take much power/current to toast them.

They are there to keep weird power surges from the coils from backfeeding into the ignition circuit. They won't allow (+) to come out of the coil, but will allow the (-) from the kill circuit through to the coil to shut it down. Kinda like a flood gate for power. Only allows current to flow in one direction.

Also, YES, you can just replace the diodes. They cost pennies. If you already bought the new wire harness, you can cut the diodes out of the new harness and splice them in to the old. (Make sure they are facing the correct direction. They only work one way) In the future, you can buy diodes all by themselves and fix the entire problem for less than a dollar.

It was the Rev limiter. Damn gremlins.

My rev limiter works great. 8k rpms? Meh....hammer down.

big thanks to Russ this afternoon holding my hand!!! Well at least my diodes are new! So. NOw that I have discontinued my rev limiter, I just need to watch my rpms now. Correct?

Yes, and be very careful who you let drive your boat. It's real easy to over rev when skipping across a sand bar or mud flat, when trying to dig out of a situation, and when trimmed way up running through stump fields.

Contemplating replaciing REV Limiter however i dont run nearly as hard or often as most of yall do. 90% of my use is climbing over logs in the Mississippi River to get back in willows to duck hunt .

How much a rev limiter cost?

I think around 200 from bps

I would replace it. It is cheap insurance.

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Don't need no stinking rev limiter!

Dumb Ass question on this rev limiter thing. Would cdi coils work on his motor? seems new 4750 rpm coils thru amazon are around $70-80 each.

He'd have to change the flywheel or have his broached. The timing is different.

so a cdi can be converted to non cdi also?

Yep