1992 Johnson V6 150 hp silver select series

[muskieman1]

Just purchased a boat with a 1992 Johnson V6 150 hp silver select series motor. Took it too my local marine mechanic for a quick once over and he indicated that it had good compression, but the power pack was not operating on 3 cylinders. Had it replaced and it ran perfectly. Took it on my first fishing trip and for the first 2 days in ran perfectly. On the last day the motor briefly (1-2 sec) powered down just after getting on plan. It happened several more time before we arrived at our spot and when decided to leave the motor would only operate at an idling speed and would bog down and shut off if you gave it gas. If you pulled it out of gear and hit the throttle the motor ran fine, but again would shut down when you put it in gear. Went back to the mechanic and he determined that the new powerpack was again not operating on the same 3 cylinders. The powerpack will be covered under warranty and my mechanic indicated that all specs for the motor were in order when he installed the original, but I?m a little concerned it may happen again. My question for the group is could there be an issue in the motor that is not being detected in his diagnostic that could cause the power pack to fail? He did make 1 comment that stuck in my mind and that is that after installing the power pack he indicated that the volts were higher on 1 bank that the other, but the lower volt readings still meet the minimum requirements to operate correctly. He should be installing the new unit next week so any input would be helpful.

Thanks for the help!

 

[metriccrescentwrench]

Re: 1992 Johnson V6 150 hp silver select series

I'm not sure if your engine has a shift assist switch or not. If it does I'd be very suspicious of that, it cuts out the 3 starboard cylinders for an instant to allow you to shift out of gear easier.

Edit - Out of curiosity I looked at your engine's parts diagram at shop2.evinrude.com and it does have a shift assist switch. Go to shop2.evinrude.com, select your year and engine, then select "cylinder and crankcase". The shift assist switch is number 76 in the diagram.

 

[Chris1956]

Re: 1992 Johnson V6 150 hp silver select series

That motor may also have the SLOW system that cuts out three cylinders when it detects an overheat condition. Perhaps one of your overheat sensors or the blocking diode is bad.

Your mechanic should know about both the shift assist switch and the SLOW system. Do you know if he checked them out?

 

[metriccrescentwrench]

Re: 1992 Johnson V6 150 hp silver select series

When SLOW is activated engine RPM is limited to 2500 rpm, below that it runs normally.

I agree with Chris, your mechanic should have checked the shift assist switch before going into parts replacement mode.

ALSO, I'd be tempted just to disconnect the shift assist switch - at least long enough to figure out if that's the problem. My engine didn't have one when I bought it and as long as I'm at idle speed I have no problem shifting.

 

[muskieman1]

Re: 1992 Johnson V6 150 hp silver select series

I do not know if my mechanic has checked either the shift assist switch or the SLOW system, but I will be sure to ask 1st thing monday morning. I will also ask about the possilility of a bad overheat sensor or the blocking diode.

Based on your description of any of these issues it sounds like a shut down on 3 cylinders would be temporary. Would any of these problems ultimately damage the powerpack?

Thanks for the advise this as been very helpful.

Wade

 

[metriccrescentwrench]

Re: 1992 Johnson V6 150 hp silver select series

Would any of these problems ultimately damage the powerpack?

No.

Thanks for the advise this as been very helpful.

We've all learned a lot here from some very knowledgeable people.

 

[jere1972]

Re: 1992 Johnson V6 150 hp silver select series

I would check the the stator Assembly, CDI has some pretty good troubleshooting steps to take on there website, had the same problem with my 99 225 first time it was a sticky shift assist killed my right back, then the Stator crapped out, killed the left bank would not run above 1100, check under flywheel and look for melting goop dripping off the charge ignition charge coils