Mariner 200 no mid range

[Flyinorchids]

I have a pair of 1990 mariner 200 2 strokes. When I put them in gear and slowly push the throttles forward, they both get to about 1200 rpm and die. If I put them in gear and floor it, they really come to life and I pull the throttles back to about 3000 and life is good. If it falls below 2200 and I give it throttle slowly, they die. Both engines are on separate tanks. Carbs have been cleaned, and were not dirty. Hope for some help. Thanks

 

[Laddies]

Re: Mariner 200 no mid range

That sounds like the back drag jets are either ther wrong size or clogged. Remove them and see if it fixes the problem.

 

[Flyinorchids]

Re: Mariner 200 no mid range

where would I find the back drag jets

 

[j_martin]

Re: Mariner 200 no mid range

I think he's talking about the vent jets. They face forward, one for each carb throat. Pulling them out makes the midrange richer.

Some setups have no vent jets in a couple of positions, so if one or 2 are "missing", it's probably normal.

A thought. What's the attitude of your boat and the trim of your motors when you're having trouble.

I have a bass bote with all the weight in the rear. It's set up for top speed, and decent riding at speed with the bow up a bit. At slow speeds, the only way it'll run is with the motors trimmed out a bit, and then it's like a durned wake board boat. Options are to idle, or blast off. Not much in between.

The problem is a combination of having the exhaust relief buried, and carb float chamber angle to horizon.

hope it helps
John

 

[Flyinorchids]

Re: Mariner 200 no mid range

John, really appreciate the help. I will try trimming it out. The motors are on a 28ft sleekcraft, kinda heavy. Luckily electric trims will make that easy. Thanks again Richard

 

[j_martin]

Re: Mariner 200 no mid range

John, really appreciate the help. I will try trimming it out. The motors are on a 28ft sleekcraft, kinda heavy. Luckily electric trims will make that easy. Thanks again Richard

When I first got this boat, I was leaping, plowing, and then getting overrun by my back wave when I quit. Then there was the hook or 2 at speed when trimmed wrong. Had to be pretty good comedy for the old salts. There's a little art to flying a boat with lotsa horses.

Let me know what you find.

John

 

[Flyinorchids]

Re: Mariner 200 no mid range

Got it runnind just fine now boys. Thanks for all the help. I advanced the idle timing to almost TDC and the old girl makes the transition just fine now. Thanks again