Johnson running like crap

OK, after a frustrating day on the water I am open to suggestions on what might be the problem…

Engine is 90 Johnson 2 stroke, 2005

It will start fine…fires right up on first crank

Will idle perfect 98% of the time.

Runs perfect wide open and up on plane

Going from neutral into forward or reverse it will bog down and die

if I am quick and can rev it up some out of gear then back to neutral and in gear it will be fine sometimes (just not much luck witht hat yesterday).

Biggest ***** is that it is not consistent. It will do the above somedays and then be fine on others. I have some opinions from friends that I should have the carbs rebuilt/cleaned and maybe have the fuel pump rebuilt/replaced.

Any other ideas? I am so frustrated with this thing I am about to just shoot it…

Also, I use regular gas, no eth, and run seafoam in the gas.

Carb

+1 on Carbs.

You might get away with spraying some carb cleaner into the throat while it is running and get some improvement. More likely, you need to tear them down and clean 'em. Your motor is a little newer than mine. But, I can do mine in about 4 hrs, start to finish. If you can turn a wrench, get a manual and read up on it. Otherwise, I’m sure ChrisV would be happy to help.

With my motor, I consider a carb tear-down/cleaning to be regular maintenance. Do it every few years and keep your filters changed regularly and the old girl just keeps on goin’.


17’ Henry O Hornet
26’ Palmer Scott

spraying carb cleaner down the throat isn’t going to do anything, you need the carburetors cleaned out and rebuilt. You need to check the fuel pump diaphragm while you’re at it. Be cautioned, those carbs are plastic and have a lot of issues. You need to have someone that’s experienced with them rebuild and install them for you. The bowls break often, the main bodies are know to warp. These parts are getting harder to get from the manufacturer as Bombardier is streamlining its part division. It gets expensive.

Any idea on what kind of bill I’m looking at to get the carbs rebuilt? I’m guessing between 300-500 ish…

— omnia causa fiunt —

Well, carbs “maybe”… just got mine back… it was the feed line from the tank. The “old” line was not used to the ethanol fuel so the tubing broke down “a bit” and clogged the intake adapter. The fuel filter just before the carb showed some of the pieces. Might wanna look at your filter and see if it has something bigger than sand in it, and check the feed lines and gas supply too. This info cost me $140 at the fixit shop. All my fuel line is now rubber capable of handling this wonderful ethanol fuel we are forced to live with.

Checked the fuel filter on the engine and it’s clean as a whistle. Fuel water seperator is clean with no water. So I guess the next logical step is rebuild carbs?! Looks like an almost $500 job. Ouch. Any other suggestions before I bite the big one?

— omnia causa fiunt —

I dont know if this will help you or not since you have a 90hp,but on the 40hp yamaha that I had it costed me 300.00 to clean and rebuild the carbs,chage the impeller and the oil in the foot @ edisto marine up here in cottageville.Or you can call the guy that has an ad in thepost &courier,think his name is ed bell.

Double D.

I has a similar problem on my 30 Johnson a few years ago. It turned out to be a carb adjustment rather than a overhaul/cleaning. There was a procedure in the repair manual to clean the “jet” (i cant remember the real name) valve on the carb. Screw in firmly, and then reset with the motor running at idle. Did wonders for mine, never had another idle problem.

You “could” do the SeaFoam thing. I got on youtube and looked at any of the carb cleaning DIY vids… it look’s pretty simple and it definitely doesn’t take a lot of technical know how to clean em. If that does not work, then go spend the bux. I can afford a $150 job but anything more I try myself first. Impellers = easy. Foot oil = real easy. Would not have known if I hadn’t tried it.

Thanks for the ideas guys. Did some more research and am thinking it might have something to do with the shift interrupt switch. Problem only happens going into and out of neutral. Kinda hesitates at times then all of a sudden takes off like the rest of the clynders started firing. Thought?

— omnia causa fiunt —

My money is still on carbs. and/or what is referred to as ‘sync and timing’ which has to do with making sure that your carbs are sync’d with each other and that they are opening at the correct time relative to the shift mechanism… if your motor does that.

Shift interrupt switch should be easy to troubleshoot, though. Check resistance with a VOM in as you shift F-N-R.


17’ Henry O Hornet
26’ Palmer Scott

Around $300 for the carb rebuilt. Double D got a good deal.

J-16 Carolina Skiff

If I recall correctly, Chris V charges $185 for the first carb and $80 for each additional. Don’t quote me on this, it was 2 years ago when he rebuilt mine. He may chime in on this and set me straight. But I think that’s what I paid.

19’ Sea-Pro CC
“Swagger Wagon”
Yamaha 115 - 2 stroke
14’ CMF Skiff
25 Johnson - 2 stroke
14’ Heritage Redfish

“There is no hunting like the hunting of man, and those who have hunted armed men long enough and liked it, never care for anything else thereafter.”
Ernest Hemingway

I have a 2001 that did the same thing sea foam solved the problem for me

grab the gaff and another cold beer

Well, I used a ton of carb cleaner and ran it on the muffs at the house. I also lubbed up the shift cable and throttle cable. It seemed to be fine, so I’m going to put her in this weekend and see how she does, fingers crossed that a $4 can of carb cleaner has fixed the problem for now…

— omnia causa fiunt —

Good luck. Even though, I would have tried cleaning through the throat first, also, that gets the cleaner into the path after the bowls and jets. So, you might get some improvement. But, if the carbs are the problem, I’d be ready to get them cleaned… Dirty throat and butterflies only means the rest of the stuff in the carbs is also dirty.

Hope it treats you well.


17’ Henry O Hornet
26’ Palmer Scott

You might also want to drain the bowls on the carbs. You might have some water laying in the bottom.

Cape romain marine is running 20% off parts and labor for till december 5. Free diagnosis. turn around 2 days. call 843-887-3330

HAPPYJACK
Luke 9:23

carb job
$159 first carb
$79 each additional carb

not 100% sure, but i dont theink the 90 has a shift interupt switch
also
engine will act completely different on the hose than it will in the rivwer

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