1999 115 Mercury Carb rebuild

[Mackfish1]

I am looing for some help on rebuilding the carbs. I have done duel carbs but never four. Any manuals or DIY guides would be great. wish me luck the stripers are running now. I have to get on the water.

thanks

 

[racerone]

What is the motor doing / not doing ?

 

[Mackfish1]

The motor doesn't go over 3k rpms. I've done a compression check and all cylinders are good. Idles rough but not horrible. I've changed plugs and fuel filter.I didn't put it away correctly last year so now I am paying for it. It ran good for the fee times I took it out. Last trip though it didn't. I checked the new spark plugs after I ran it with ears. The two bottom ones don't look like they were firing. I have good spark out of all 4 so I assume is not getting fuel. Hence the carb rebuild

 

[racerone]

When you are idling on the hose the bottom 2 carburetors do not work as per design !

 

[Mackfish1]

I am not sure what you mean.

 

[racerone]

Your motor may well be what is known as a " 2 + 2 design "---These motors only get fuel on the top 2 cylinder for idling.---Bottom 2 carburetors kick in once motor exceeds 1800 rpm or so.----The bottom 2 cylinders do not get fuel at idle.

 

[Mackfish1]

Ok Carbs are rebuilt. It was not too bad but the motor sounds like it is wrapping at about 3k. Its the same before I took them apart. When I have it on ears in the driveway I get it to about 3k and wraps something awful. But when I really jump on the accelerator it will rev higher. Its like before the other carbs kick in it doesnt want to go. Racerone if that's what kind of engine I have. I don't want to do that too much and pop the engine. Any thoughts at where to look next?

thanks in advance for any help.

 

[racerone]

" cleaned the carburetors and motor still runs the same "----That is a very common statement.---More trouble shooting needs to be done.

 

[flyingscott]

Have you checked the stator that is an issue with those motors.

 

[Mackfish1]

Racerone please give me the next place to look. Flyingscott I am not sure what the stator is. I am still a newbie. Yes I admit it.

 

[Mackfish1]

Flyingscoot. How can I check it?

 

[flyingscott]

First thing you need to do is get a factory service manual. The second thing is it is not an easy motor to get set-up correctly so you need some patience. Then a compression test and spark test.

 

[Mackfish1]

Compression check ok and spark test is fine. What would be my next option?