94' Dt65 loses power

[Natedog172]

I have a 1994 DT-65 on my skiff. At first it was a great motor, but i have owned the boat a month now and there is a problem. At wot or just on plane the motor slows. Almost like a cylinder stops fireing. The problem only presents it self after a 45 minute run early in the morning, and then intermitantly between every 5 and 15 mins in the afternoon. It doesn't die completly. I replaced the fuel pump and the fuel filter and lines..Could a coil be going bad? Also plugs are new...Water pump is great..The primer bulb stays hard during the situation..I have read a lot of other peoples posts on here, but none sounded like my problem. Thanks

 

[mphelle8vld]

Re: 94' Dt65 loses power

That motor is protected by 4 systems, over-rev, low oil, low oil flow, and overheat, any one of which will reduce the engine speed to 3000rpm. Let us know if you have a working monitor gauge which should tell you what system is shutting down to protect the motor.

 

[Natedog172]

Re: 94' Dt65 loses power

It reduces to just about idle. 1500 rpms...then dies if i give it gas. I now know it happens when there a moderate to heavy chop. It does not do it if some one squeezes the primer bulb, and i only run it 4500 rpm. But the bulb does not lose any pressure. It stays rock hard the whole time. Its gotta be in the carburator, float sticking or something like that..As soon as you shut off the motor squeeze the ball even though its still rock hard then start her back up shes off and goin again...I also bypassed the quick disconect with brass fittings to elminate the possibility of the o rings being bad and allowing air to get in...

 

[Natedog172]

Re: 94' Dt65 loses power

After takin carbs off to clean them I discovered the oil flow sensor wires were loose. They came right out when i touched them. Then i noticed a little plug that went to nothing. After consulting my shop manual it says it should be connected to an ignition system timing resistor. I am missing that peice. I bought the motor like that. Could that be messing my stuff up?

 

[mphelle8vld]

Re: 94' Dt65 loses power

The 94 factory manual calls for a timing resistor with a value of 104-156K ohms, my spare shows 131K. If the circuit is open, or in your case missing, it will retard the idle ignition timing. If it is shorted, it will advance it. Again this is for the idle timing so not sure if has an effect on your issue. Still waiting to hear if you have a working monitor gauge.