2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

[bishop1976]

Took the pontoon to the lake last weekend and the motor ran great for a day and a half. I noticed an intermittent rough idle. This motor has an oiler but I also added some oil to the tank for added protection. This is common practice for us on the pontoon because we pull the kneeboard with it often. Well the intermittent rough idle became permanent and continously got worse. Over an hour it would start dying when at idle throttle. We took it back to the dock and it ran great at WOT no issues at all. Checked plugs and looked for a possible spark jump after dark but were not able to find anything. I took it over to the marina the next morning and they ran a compression test. 125 on both port cylinders and 120 on both starboard cylinders. They put in new plugs, cleaned one lower card, and said they set the timing and adjusted the cam timing which they told me was a little off. The motor still idled a little rough but the mechanic said it could be some trash in the carb and that I should run it and see if it smooths out. Well we ran it all day with the rough idle which never seemed to get better. WOT was still A-OK. On Sunday I was pulling a kneeboarder back to the dock when we went through some pretty rough wake. About the 3rd wave the engine stalled out. It would fire and run for a few seconds then die. We had to get towed into the marina and I assumed we must be out of gas. We fueled up and I tried restarting but more of the same. I pumped the bulb a good 50 times and it would not stiffen up. Just limp bulb not collapsed. I did get it to run for a few minutes right before we pulled it out but it died before I got it all the way on the trailer. After the rough idle started it would run great at WOT but you had to walk the throttle up slowly and let the motor catch up or it would stall. It was also kind of weird where if you moved the throttle up it would go to WOT vs a smooth take off. You could then throttle down between 2800 to 4800 rpm's and had good control but the minute you went back to idle it was rough and you had to coax it back to the sweet spot.

We brought it home 160 miles fromthe guy at the lake that worked on it. I took it to a trusted guy here but he says it will be two weeks before he can start on it. Is there anything I can check between now and then? Anyone have any ideas of what could cause this?

 

[tashasdaddy]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

sure sounds like you are in for carb cleaning, and rebuild kit. clogged low speed jets. do you have a fuel/water separtator canister filter on the boat? if not get one.

 

[bishop1976]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

Problem resolved......fuel filter was stopped up. Why the other shop didnt catch this I'll never know. Should I ask for my money back?

 

[bishop1976]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

Got the boat back. The shop got it running again after a crab rebuild and new fuel lines. Now it will not idle properly. It spits and sputters then dies. If you give it more throttle to help it idle it either gradually idles up too high or dies. I sure think it has a miss but the mechanic doesnt think so. All compression tests are good. Does anyone have any suggestions? He says that the carbs may be out of adjustment. I took it back today.

Beofre any of these problems this motor idled like a dream. Quick to start and you barely knew it was back there. Now it has a rough idle and vibrates some while idling.


Pls HeLP!

 

[tashasdaddy]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

they did not get the carbs clean, or the fuel line still had crud in it.

 

[bishop1976]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

I would agree but they replaced the fuel lines. This is really starting to get aggravating. $1,000 and it still isn't right. Pumping the primer bulb had no effect on idle at all either. Usually with a fuel restriction this will idle the engine up.

 

[bishop1976]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

Anyone???

 

[SKEETR]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

Sounds like they may have blown something into the idle passages during the rebuild. Maybe they neglected to pull the core plugs in the carbs. Repair experiences like that are what drove me to get a manual and do all of my own repairs.

 

[dmaaero]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

I have the exact same engine doing basicly the same thing for about 6 weeks now!!! I went through the carbs 2 times, the shop has been through them 3 times. it still isn"t right, i"ll try the core plug tommorow if i can get a carb kit. From pulling the plug wires it"s the #1 cyl. sounds dead at idle, manual says use gasoila sealer on the new plug, never heard of it, whats a equivlant sealer to use inside the carb?

Bishop, One thing you might want to check when you get your boat back is make sure all your plugs are gaped at .030 plug gap makes a big differance on a 2 stroke,

 

[dmaaero]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

A 2002 90 hp johnson does not have core plugs. Core plugs can be found on a 40/50/55 or on older engines with metal carbs. Core plugs are not found in newer plastic carbs.

 

[bishop1976]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

Please reply back when you get a resolution

 

[bishop1976]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

So the mechanic called......

He first says that the gas sample that he took doesnt look the same as the other that he got when it was in the shop before? And then after I told him that I didnt put any gas in it he said the tank has water in it.

Then he proceeds to tell me that I have cracks in my carbs. What I don't understand is how would he not notice this while doing the rebuild? New Carbs cost another $1,000 plus labor.

This is a 2002 Johnson 90 hp. What do you guys think?

 

[bishop1976]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

I'm hearing that Johnson discontinued manufacturing parts for the 2002 90 hp. No carburetors available at any dealer. Any ideas on why they would do this on such a relatively new engine and where I might find replacements?

 

[clanton]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

60 degree looper, or 90 degree crossflow engine?

 

[bishop1976]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

60 degree V4.

 

[dmaaero]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

i fixed mine !!! started opening all 4 carb setting screws 1/4 turn at a time. factory was 3 3/4 turns, about 4 1/4 turns it started to get better finally at 4 3/4 turns it runs like it allways did, perfect no more stalling when putting in gear.

also found the original gaskets on all the carbs after i paid the stealer for a rebuild

bishop one of your carbs having a crack, i guess thats possable but all 4 i call bs on that one. get you a allen wrench an a flashlite, start backing the mixture screws out 1/4 turn at a time an see if it fixes yours. rember when you screw them in to seat them, light touch, dont want to bend the needle screw.
Ran perfect all day yesterday,
3 trips to the stealer an i fix it by adjusting the carbs
having a boat that runs right again

 

[bishop1976]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

I'll give that a shot. I dont think this guy rebuilt anything either.

 

[clanton]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

Remove the coils and check for arcing from the coil to the metal plate that covers the pack, you will see a burnt spot on the plate, then check the pack output to the ignition coils. I think the spec for the pack output is 150 volts with a peakreading meter.

 

[4nukater]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

Going out to check my power pack now. My motor runs great at home and when I leave the dock. After a run awhile it does what everyone else claims. I cannot beleive it is the carbs or fuel or plugged carbs. I hope your answer is what I am looking for. I will let you know.

 

[Scottycat]

Re: 2002 Johnson Bombardier 90 rough idle and stall...finally dying help pls.

Well, I have a 1995 50 HP Johnson VRO (mix in tank now).
Boat ran like a top at the end of the season, like brand new.

Kept indoors all winter, not heated, but not freezing either.
Gas is fresh. Bulb is and fuel line are new and bulb gets hard.

Start it up and it can't idle, rev it up, slap into gear and it takes off like a champ. Bring it back to idle in gear, dies again. (all on water, barely will run in driveway)

Pulled main jets, cleaned reset, opened bowl drains, cleaned them out.
Checked resistance on coil and wires, good.
Idle is set per factory specs. (have original shop manual)
Will change plugs later this week when they arrive.

Checked all hoses, good.

I am pretty sure the top cylinder is not firiing as the motor does not sound like it is. I sprayed carb cleaner in the top carb at idle in drive, motor perks up, spray in lower carb motor dies out.

Place hand over top carb and motor perks up, place hand over lower carb and motor dies out.

Will check spark and coil voltage output tomorrow.
If that checks out I will re-adjust the main jets 1/4 turn at a time.

Anybody have a clue??

I hate this feeling of the unknown, can only be whole again when this puppy is running good again.

Also, to the 2002 Johnson, check your coil for resistance and replace your plugs even if they are only a year old, you need to start eliminating all the small items first.

Thanks fellas.
-Scotty