Mercury classic 50 no power after low speed trolling

[k5blazerboy]

At launch my boat did 28mph
I trolled for an hour at 1.6mph
We went to take off, boat only did 6mph
I did a compression test, 130 on all
Replaced plugs, didn't help.

What could be wrong?

 

[carholme]

Re: Mercury classic 50 no power after low speed trolling

When you were only doing 6mph, what were the engine rpms? If you don't have a tach and felt the engine was producing power, you may have a spun prop. You can check this by putting a witness mark across the prop hub (rubber and metal), launching it again for a short run around, alternating the power from idle to max. Then back to shore and see if the witness marks are still in line or have shifted. If they have shifted, you will know that the rubber has spun inside the hub.

Gerry

 

[k5blazerboy]

Re: Mercury classic 50 no power after low speed trolling

Funny you mention that, I had actually just picked my prop up that morning from the shop after getting a new hub put in. I do not heave a tach, but I could definitely tell it was not hitting full rpms

 

[crazyhunter]

Re: Mercury classic 50 no power after low speed trolling

try cleaning your carbs i have a 40hp classic and mine did the same thing it wouldnt rev all the way and would only run about 7mph

 

[k5blazerboy]

Re: Mercury classic 50 no power after low speed trolling

Cleaned the carbs, still isn't ruining right. Also replaced in line fuel filter. Still only 6.

 

[k5blazerboy]

Re: Mercury classic 50 no power after low speed trolling

Update:

Tore apart my controls, as it was not preventing the shifter from going into forward from neutral, and found that plastic cam to be broken. Could this have anything to do with it?

Also, fuels pump maybe? Going to go check that now.

 

[crazyhunter]

Re: Mercury classic 50 no power after low speed trolling

i am not sure about the throttle but to test your fuel pump rev it up to the point where it starts to bogg then pump your primer bulb if that helps then its your pump if not i looked at my paper from where i took mine to the shop when it was doing that and it said carbs and a ignition wire was resting on the block and was shorting out. i dont know how to check that i had a mechanic do that.

 

[k5blazerboy]

Re: Mercury classic 50 no power after low speed trolling

Another update, found the top two coils had no spark, so I ordered 2 new coils, got them installed today and........guess what still nothing. Now what CDI? I hope not because that was just replaced a year ago and I can't see how that could be fried again. Any other ideas?

 

[k5blazerboy]

Re: Mercury classic 50 no power after low speed trolling

So I switched the green wires around coming off of the CDI to the coils to test if those coils would get power, and in fact they did. I assume I need a new CDI, AGAIN!!! This motor has cost me way more than its worth. If I have spark on 2 cylinders, it cannot be the trigger, right?