Maiden voyage results

[onefast66nova]

OK I just got back from running my boat. Ran it for about an hour and then started having issues. The right engine under full throttle would climb to just shy of 7000 rpm. Then the rpm would surge down to 5000 the.n back up. Didn't do this every time. If you kept it about 4500 it would be fine. I will attach pics of the plugs. I have 40:1 in the tank and I just reinstalled the oil injection as the po deleted it. Left engine didn't miss a beat. Also the pisser holes out the back didn't shoot like my buddy jet ski it was more of a weak stream. The gas is brand new 91 no ethanol. I also took apart and cleaned the carb but all the parts looked like new. The po stated he ran marine sta-bil every tank. The low and high speed are set to factory specs. Any direction to try now. Thanks in advance. Bill. Btw it's a 95 speedster

 

[jhjesse]

Check your pulse line and make sure it is not kinking, cracked, or leaking.

 

[onefast66nova]

I just did compression check and 135 each cyl. The pulse line is new and on with worm clamps.

 

[jhjesse]

Disconnect the red wire from the rectifier and go ride. If it clears up then your rectifier is bad. 135 is not great but should be ok. Plugs look good.

 

[onefast66nova]

So should I try anything carb wise or since it don't do it all time leave them be. Trying to get it all fixed for a trip Sunday. Could I use it without the rectifier and what effect would unhooking it have.

 

[jhjesse]

Because your plugs are turning chocolate brown and there doesn't seem to be any hesitation in acceleration the rectifier trick would be my next step. When you disconnect the red wire you run just on battery until you completely discharge it. I don't recommend doing that. Disconnecting the red wire is merely a test to see if it is converting AC voltage to DC voltage. When a rectifier goes bad it allows AC voltage to enter the electrical system creating all kinds of strange things to happen.

Edit: I don't recommend running with the red wire disconnected for more that a few minutes just to see if that is indeed the problem.

 

[onefast66nova]

Ok but if that was the case would that mess with the other engines electronics or since that mpem is running separate engines they won't bother each other.

 

[onefast66nova]

Another question while I'm at it, the oil level in tank dropped so by that can I fill up with straight regular. And would the less oil effect my plug color.

 

[jhjesse]

Ok but if that was the case would that mess with the other engines electronics or since that mpem is running separate engines they won't bother each other.

Not necessarily......

 

[onefast66nova]

Ok so went out and pulled electronic box cover off and after I got about 1/2 the screws out water started pouring out of it! The gasket on the lid is there and all the wires going to it go through grommets. Where could this water be coming from?!?!

 

[jhjesse]

Umm...looks like you have found where to start. I would dry it out and clean every electrical connection one at a time using dielectric grease to reassemble. Pull all the fuses use electronic cleaner and reassemble with dielectric grease.
When you reassemble the cover I seal it up to prevent this in the future.

 

[onefast66nova]

Ya wonder how it all got in there. Those gaskets get lose over time?