No power under load 1985 merc. 35hp

[tfendley]

Clean carb. Good compression on both cyl. (150psi). Great spark. Fuel pump seems to be operational. Starts and idles when you go from idle to WOT it bogs but will go WOT fairly quick. All while on muffs, when you put it under a load it just bogs if you slowly ease into it and dies if you hammer down on it.
Please Help B-4 I SINK IT.

 

[tfendley]

Re: No power under load 1985 merc. 35hp

Throttle advance, timing issue??

 

[achris]

Re: No power under load 1985 merc. 35hp

Clean carb. Good compression on both cyl. (150psi). Great spark. Fuel pump seems to be operational. Starts and idles when you go from idle to WOT it bogs but will go WOT fairly quick. All while on muffs, when you put it under a load it just bogs if you slowly ease into it and dies if you hammer down on it.
Please Help B-4 I SINK IT.

A quick test is to just give the choke a quick flick as it's bogging. If it takes off like a startled gazelle, then the idle mixture screw needs to be opened (richer) about 1/8 turn.

Chris.......

Please Help B-4 I SINK IT.

And this is unnecessary. We get that you want help, that's why you're here. Threatening to sink a boat will just cause people to ignore you....

 

[tfendley]

Re: No power under load 1985 merc. 35hp

I had no idea we could not use humor. I apologize.
I have already tried that thinking the samething. I was getting water in the top cylinder. I pulled the powerhead and changed the exhaust gaskets, that cured that prob. Any other suggestions?

 

[achris]

Re: No power under load 1985 merc. 35hp

I.... I was getting water in the top cylinder. I pulled the powerhead and changed the exhaust gaskets, ...

Any other information you care to share before I make a complete idiot of myself?

Pulling the powerhead is fairly invasive, so I would be checking all the basics first, including the tuning. And if you've done that it would be nice to say so straight off the bat too.

Chris......

 

[Michael F D]

Re: No power under load 1985 merc. 35hp,,, 50 hp too

Re: No power under load 1985 merc. 35hp,,, 50 hp too

I have similar problem with my 50 HP 2 stroke 4 cyl
Engine top end has gradually degreased to the point of no power at all after1/3 throttle. Bogs, cant get out of its own way
While trying to figure out why my 50HP merc outboard has no power I have rebuilt both carbs, they did need it. , No change,, compression test- good. Tested with meter everywhere, all good.,.Installed new stator, no change, new switch box, no change. While examining the engine at dockside in the dark looking for a electric leak I spotted a twinkle on plug boot #4 and had a AHAH! moment,,, for a moment . Well, it turned out to be water coming out from around plug#1.
What? So,,,read up on it and changed the Water jacket Gasket and 2 bolts did break on the right side,,, bummer! Soaking with penetrating oils for weeks did not seem to help as white oxidation appeared dry as a bone upon examination after bolt removal, After I got the jacket plate off I had two good stubs to work with. . I used a propane torch to heat them and spray more oil and tapped lightly with hammer for 10 minutes,, then gentle stress back and forth with large vise grips until they broke free and then I slowly went back and forth a little farther each time until it moved a complete turn,,then all the way out. rejoice!

Installed new gasket,, test boat,, no difference,, red herring I guess. Boat starts easily and runs fine at dock or test tank, is the exhaust cover gasket my next guess repair? Summer is slipping away,,need to get past this.

 

[tfendley]

Re: No power under load 1985 merc. 35hp

pull your plugs and check for water on them.