motor issues

[red32131]

Ok, I started to have issues with my 98' 150 vmax (carbed) in July. At low speed it would hesitate and run very sluggish. When I "hit it" to run, many times it would die, I have to feather the throttle just right to get her to get up and go. At idle, I would have to hit the choke just to keep it running at a no wake speed. Now it is just sluggish, she sputters (sneezes @ Idle) and now it surges at WOT.

What I have done so far...(in order)
New primer bulb
New Fuel Pumps (now the bulb will pump hard instead of leaking)
Dunks decarb
New plugs

Anyone have any other suggestions? I am at a complete loss now!

[Pacer]

sounds like its time to pull the carbs and clean them. Its not good to run a 2 stroke lean. Thats how pistons sieze. You should be able to do the job yourself in a couple of hours.

[Harry Simms]

That sounds like the way my son's 99 Johnson 150 was running. We rebuilt the carbs and it runs great now. Getting the carbs on and off is a little challenging, but not too bad. The actual rebuild of the carbs is simple.

[jbfarm]

I had the same problem. Turned out to be the fuel line from the pumps to the carbs had delaminated sending small chunks of liner into the carbs. Clean out your carbs change the fuel line and it should be good as new

[red32131]

I talked to a local shop and they said that I should not rebuild the carbs if I don't know how to sync them up when I put them back on. I have a fair amount of mechanical ability and think I could handle it. Just concerned about the whole "syncing" thing... should I be concerned about that? Anyone have the schematics for the tear down? May be a good winter project for me.

[Pacer]

Carbs have adjusters that let you fine tune the low and high speed fuel air mixtures. These look like screws going into the side of the carbs normally made of brass, with a spring on them. Before you remove these, turn them in untill they bottom out, and write down how many turns they were out. Don't tighten them down, just turn until it gets a little snug. these will look like a needle with threads on it when you pull it out. when you put them back in after cleaning, bottom them out again, and then turn them out how ever many turns they were to start with.

do one carb at a time so you don't mix up parts, sometimes the jets will be different. If you get confused wit the carb you are working on, you can look at one of the carbs that is together.

[red32131]

These screws you are speaking of are inside the carbs right? Anyone have a schematic for these carbs? Is that what the shop meant by "syncing" the carbs?

[Rich Z]

The linkage that controls all three carbs is what needs to be in sync. The screws on the outside of these carbs are for low/idle mixture adjustment only. The best way to clean them is to drop them in a sonic tank for 30min in sol-safe or any other solvent that can be used in a sonic tank.