Mercruiser 250hp 5.7L rpm drops by it self

[jabfd]

While cruising my engine rpm drops from 3800 to 3200 it never stalls. I putted along at idle for a little while and then got it back up to 3800rpm and everything was good for a while then the same thing happens. I unscrewed the gas cap to make sure my vent line wasn’t clogged up and problem is still there. I did notice that when I accelerate fast even in neutral I have a hesitation for a second and then the throttle goes up. Would this be the carb?

 

[alldodge]

Would this be the carb?

Maybe, need to check fuel pressure 3-7 psi

 

[QBhoy]

Is this maybe for the mercruiser section ?

 

[jabfd]

Sorry don’t know how to transfer it over to the mercruiser section

 

[alldodge]

Morning GA_Boater could you move to the Merc section, Thanks

 

[GA_Boater]

Morning GA_Boater could you move to the Merc section, Thanks

jabfd Done and in it's new home.

The hesitation from idle when quickly moving the throttle is usually a sign the accelerator pump is worn. Probably carb rebuild time.

Have you changed fuel filter(s)? There may an inlet filter where the gas line attaches, along with a water separator/fuel filter.

 

[wellcraft-classic210]

Sounds like you could have Debris in the float bowl of the carb which can block fuel flow through the small feed passages

A Good Carb cleaning would fix that or rule it out

 

[jabfd]

Thanks for moving me to the right section.
I did change out the fuel/water separator and the gas looked clean I will check the carb screen again and probably pull carb and order rebuild kit.

 

[Bondo]

While cruising my engine rpm drops from 3800 to 3200 it never stalls. I putted along at idle for a little while and then got it back up to 3800rpm

Ayuh,.... If that's yer Wot rpms, yer seriously Luggin' yer motor, which leads to big holes in the pistons,.....

You should be seein' 4800 rpms at Wot,.....

 

[jabfd]

Bondo. My wot is around 4400 3800 was my cruising rpm at 24 mph

 

[alldodge]

The stumble taking off in is a carb issue, the loosing power at cruise is most likely fuel pressure. Low fuel pressure can be the pump or a restriction

 

[jabfd]

ok I am going to check all fuel components over the weekend I will let you know how I make out thank for everyone input !!