mercury 150, bogs and wont hit max rpm

[66jj]

I havent used my boat much over the last 3 years. 3 years ago it ran and worked fine at all rpm.

Last year I only took it out once to a no wake lake and it motored around ok.

This year I took it out and it bogs when trying to take off and very slowly gains rpm and only will go to 4200 rpm. 5500 rpm is normal.

It would only go to 2900 at first. So I took it home drained all the gas and put in two seafoams, new plugs and filled it full of new gas.

Its still only going to 4200 rpm and absolutely doesnt run out of the hole, stumbles and bogs and slowly slowly gains rpm.

I havent changed the visible fuel filter on the motor yet, but I ran it for 45 minutes around the lake at 4200 rpm yesterday.


Thanks for the help, Jeff

 

[andy6374]

Re: mercury 150, bogs and wont hit max rpm

First, check to make sure you haven't dropped a cylinder...i.e., verify there is spark on all cylinders.


Since it sat so long with bad gas, you probably have varnish buildup in your carbs and possibly other fuel components. You might want to clean the carbs and replace the fuel lines. I'd also change out the 3 year old spark plugs too.

 

[L23]

Re: mercury 150, bogs and wont hit max rpm

Jeff
I had the same problem and what I found was the new ethynol in gas is destroying fuel hoses. I replaced my inline filters also replace the fuel line from the filter to the motor. The hose from the filters to the motor tends to have an inner jacket that breaks down and clogs your diaphram. The diaphram has 4 orifices (2) for low rpm and (2) more for a total of 4 for high rpm. Open it clean this out and it should help. Good Luck