2000 Merc 5ohp very sluggish under power

[peckh111]

We can't figure out what's wrong. The merc starts fine, auto choke works, revs fine in neutral. As soon as it is put in gear and throttle applied, it totally bogs down and has no power. Have gone through the entire fuel system, there is no foreign junk around the prop shaft, I'm stumped. Any ideas?

Thanks
Harold

 

[carholme]

Re: 2000 Merc 5ohp very sluggish under power

Harold;

What is your engine s/n?

Do you have a tachometer? You say it bogs down, by that, do you mean that the rpms will not increase at all when the throttle is advanced in the water? Or are the rpms increasing OK but the boat is not moving?

Do you have the service manual?

Gerry

 

[peckh111]

Re: 2000 Merc 5ohp very sluggish under power

It is my friends boat. I will get more info. I have been reading through a lot of posts to try to get some suggestions. I'll add info tomorrow. He had to a mechanic and after $1300 and 30 hrs, it is the same symptons as before. I'm beginning to think electrical, like stator, CDI, etc. I can't imagine that they didn't try at least 2 sets of plugs.

Harold;

What is your engine s/n?

Do you have a tachometer? You say it bogs down, by that, do you mean that the rpms will not increase at all when the throttle is advanced in the water? Or are the rpms increasing OK but the boat is not moving?

Do you have the service manual?

Gerry

 

[Bob_VT]

Re: 2000 Merc 5ohp very sluggish under power

A two stoke will "rev up" and sound fine even when it is not running on all cylinders. I don't think too highly of the statement that a mechanic dis the work and it is still bad. My first stop would be back on that mechanics doorstep.

Get a manual
Start with examining the spark with a spark tester.
When were the carbs last rebuilt?
Get a tach...... if your friend is serious about boating a tach is an essential item.

 

[peckh111]

Re: 2000 Merc 5ohp very sluggish under power

Thanks Bob. I couldn't agree more. I will follow up with what I find.
Harold