Another Johnson 150 problem

[bvail91]

"On the last few outings, my m

"On the last few outings, my motor has initially started and ran without any problems. After about an hour on the water, I begin to have problems with the motor. I can usually crank it easily but as soon as I give it gas, it bottoms out and dies. It was idling fine, but lately has gotten to where it won't do that either. I've changed the plugs and treated the gas with seafoam (which unfortunately is approaching the limit of my abilities). I've heard others talking about carb kits and was wanting to know if that should be my route or if anyone might have experienced something similar. Thanks in advance."

 

[kainon]

"can start with adjusting the

"can start with adjusting the low speed idle mixtures, but the problem could be 1 carb, there are a couple ways of testing, it's best to do it in the water too, expecially adjusting the carbs."

 

[bvail91]

"Thanks Brian, is there a webs

"Thanks Brian, is there a website that will provide a little step-by-step for this. I tried adjusting the carb on my old boat and managed to screw it up worse than before."

 

[kainon]

"you might be able to google f

"you might be able to google for a site with some tips, or how to, I never looked so I'm not sure.

I use Carb cleaner or some fuel mix in a spray bottle(prefer) and spray in the carb while its running(not good when back firing though) and if the engine dies down that carb should be rich enough, if the engine races up, that's the lean one, some times you need a helper with the throttle control.

I either have the boat tied well to a dock with a bunch of bumpers or tied with transom straps to a trailer (depends on the ramp) so I can run it in forward as underload is how the engine is going to be run, you can get close using a hose for the water source, but without the load on the prop the engine doesn' need the same amount of fuel.

Turning the screw out lets more fuel in upto about 1500-2000rpm then the carb is working with the Jet in the carb.

If there's not enough fuel with the idle mixture srew the carb wont transition well to the secondary circuit(jet) and the engine will loose power, take each carb 1 at a time.

First you want to get a good idle, where it sits and idles nice and smooth (little to no shaking) then you work on powering up where it transitions smoothly and wants to push the boat up and over the trailer (dont do it though)"