Another boat motor question.

Chuck7 · 12-30-2006, 01:25 PM

This is the 2nd time this has happened to me with my new Nisson 4 H.P motor. I'm driving along and then the motor wants to die down ...unless I open the choke a little. It has less than 5 hours on it. Correct me if I'm wrong but doesn't it sound like it may just need a little adjustment on the carburator screw?? The repair place is 40 miles away..too far I think. SOunds to me like it's just simply needing gas. It used to idle too at real low RPMs ..it doesn't now.
c7

JoshKeller · 12-30-2006, 02:28 PM

4 stroke?

Chuck7 · 12-30-2006, 02:39 PM

Yes,..I just looked.It has 2 screws to adjust..One is at the butterfly near the ventura idle screw I beleve{ Topof carb} the second screw is toward the bottom and is a little black screw

JoshKeller · 12-30-2006, 02:49 PM

how long has it been since you pulled the carb and cleaned it? If its never been done, pull it apart, and spray it down really well with carb cleaner, then blow it out with some compressed air. Do it 3 or 4 times. It only takes one tiny little particle in the carb to lean it out. i honestly thought most 4 strokes were DI.

Chuck7 · 12-31-2006, 02:30 AM

Josh , this motor was only bought last June.It still has 2 1/2 years of warranty on it. I've had similiar problems with other small engines and sometimes a little turn of a jet can do wonders. If it doesn't..I'll take it to the dealership.

It could be very well dirt as you mentioned. I mean there is no reason to be going at full throttle and then dying down. Usually a jet needing to be adjusted is because of white smoke/ sputtering, or engine failing to idle. I'm not sure if a dirty carb would be a warranty item or not. It seems there should be a screen or filter between the gas line and the carb.

c7

Chuck7 · 12-31-2006, 02:58 AM

Josh,
I found an online manual.It's very vague but I do believe your right about the dirt. It certainly shouln't need an adjustment yet. They said to ..
1. Check the fuel cock mesh???

2, And check the fuel filter. / clogged line.

a. Also may need adjusted.
b. may need fuel pump cleaned

JoshKeller · 12-31-2006, 04:36 AM

If your using an external gas tank, I would highly suggest getting a FRAM inline fuel filter from wal mart. They run about $2.50, and they do catch a good bit of dirt. Tearing a carb down and cleaning/rebuilding is easy if you have an air compressor. Take a picture before each step of the tear down and save in case you need the reference. On my motor, I tear them down and clean them out every 3 - 4 months. Think on the plus side, a carb clean is almost free and much easier than a injector going bad

Chuck7 · 12-31-2006, 04:53 AM

Mine is an internal tank Josh.
Thanks for taking the time to reply. I appreciate it.
c7

Chuck7 · 12-31-2006, 06:39 AM

Josh,
I found an online manual.It's very vague but I do believe your right about the dirt. It certainly shouln't need an adjustment yet. They said to ..
1. Check the fuel cock mesh??? I located the fuel cock.It's a valve that allows me to run either an external or and in line gas tank. I'm running an inline . I took the valve cock apart and found the screen. There was some rust flakes in there . I flushed it out with carb cleaner and then blew it ftrough gently with my air compressor.
I figured the gas should not be getting past the screen to my carb... by the way that fine screen looks..it shouldn't

2, And check the fuel filter. / clogged line. I located the inline filter.I blew air through it..it was fine.

a. Also may need adjusted.
b. may need fuel pump cleaned

GOTTA ..GO!..the carb cleaner and gas are burning up my wrist...[X(]
When I took off the hose.....she shot out faster than I was thinking.

longcut36 · 12-31-2006, 06:55 AM

chuck I had a 7.5 Johnson doing about thesame thing. what it turned out to be was the vent on the gas cap was stopped up and wouldnt let air into the tank when I unscrewed it. good luck