Johnson 150 still has a little stutter in it. ???

General Boats and Motors
1

Cleaned out my fuel filter on the motor and added one more just ahead of my water seperater. Put on a new water seperater too. Emptied all 6 bowls on all 6 carbs. I did find a little trash in them but pumped it all out with the bulb. Motor runs like a top. Easy starting good strong acceleration. At wide open throttle running it’ll stutter a little here and there. Can’t figure out what it is. Any ideas? Is this what happens with water in my gas?

Being superstitious is bad luck.

2

I am thinking high speed side of the carbs (jets)need cleaning. May need to disassemble, soak and rebuild. It is not difficult to do.
I am assuming it is a 2 stroke.

Rick

3

Yep. I bet ECU hit the nail on the head. I bet your carbs aren’t completely clean and the only time the problem shows is when you’re pulling full flow through them.

I also wonder about your filter setup. It sounds like you have a few inline. Multiple inline filters will add restriction to your fuel flow. One good spin on type water separating filter will do all the filtering you need.

17’ Henry O Hornet
26’ Palmer Scott

4

Thanks, I don’t know what to say. ??? The boat will run wide open for a few miles without a stutter at all. Seems like if it was a carb problem then I’d never get smoothe wide open throttle. I just don’t get it. I guess I’ll have to tear’em down and clean them very well.

Being superstitious is bad luck.

5

Make sure you synchronize them (linkage) when finished and get a manual and set your air/idle screw at the right setting when done. The book will tell you how many turns from seated to back the screw out.

One more thing: when it is missing at wide open throttle, have someone pump the bulb and see if it picks back up. That may mean fuel delivery issue, Ie: fuel pump, air leak, etc.

Rick

6

if you found trash in them, and didnt take them apart and clean them, you are flirting with disaster.
at WOT, you run 1 cylinder lean for just a minute or 2, and you will be in the market for a rebuild or repower

I’m now at www.teamcharlestonmarine.com

7

Sounds like your carbs. Might as well get the fuel pump cleaned out while you are messing with the carbs. If not, you can have clean carbs and your fuel pump can put garbage back in your carbs and you will be back at the same problem. I learned this the hard way.

8

Thanks.

Being superstitious is bad luck.

9

one or more of your plugs could be breaking down under load. id pull them clean and check the gap, it would be an easy fix if so.

23’ May-Craft Pilothouse
175 Ocean Runner
http://www.brookssigns.com

10

I have a 130 which had the same problem but mine was the fuel pump

Ronnie Burbage