Merc 25hp 4 stroke hole shot (power loss)

[totallyconfused75]

I have a 2007 merc 25hp ELPT 4 stroke with a stainless steel prop (dealer installed). It's on a 1648 tracker grizzly and it has a CMC breakaway unit which allows the motor to "kick up" when it strikes under water obstructions. It's seems like I'm experiencing some power loss when trying to get out of the hole and up on plain. Once up and running, the motor has NO problems - it runs great at that point. It just seems like taking off is real struggle for the motor. There is no rough running or sputtering or anything else, just no power to get out of the hole and then it's off to the races!!!

Anyone have any idea what may be causing this??? I realize that it's not going to have the same low-end torque as a 2 stroke, but it seems more sluggish than last year!!

Other than this, I love this motor! It is very quite and smooth running and it starts extremely easy even in cold weather!!! Just need a little more low end power!!

 

[CharlieB]

Re: Merc 25hp 4 stroke hole shot (power loss)

Very small Idle fuel inlet passages are prone to clogging from ANYthing, from dried fuel deposits to dust accumulation during periods of non-use.

Also check the accelerator pump shot, it gets weak from fuel/varnish deposits in the check valve.

I expect a very careful carb cleaning will restore your holeshot.

 

[totallyconfused75]

Re: Merc 25hp 4 stroke hole shot (power loss)

Thanks for the suggestion. We have two weekends left in our duck season here and I'm going to give it a good once over! I will certainly check these areas...thanks again!

 

[BF]

Re: Merc 25hp 4 stroke hole shot (power loss)

Hi there,

Maybe I misunderstand... isn't yours a 4 stroke EFI? If so, carb cleaning is not in the cards. It's also not clear to me whether this is a new problem, or just how it's always been. Perhaps the motor is overpropped and it managed to "get by" last year until you added more gear/weight to the boat? What pitch are you running? Do you have a lower pitch prop you could try?

BTW, I have a merc 25 hp 4-stroke EFI, and if anything, I think it has better torque than my old 25 hp evinrude... The 2 strokes run real strong at higher rpms, but it seems to me like the 4 stroke has more grunt on the low end to mid-range.