Fix for Johnson 2000 90HP missing above 3000RPM

[shadetree101]

I just found the problem with my 2000 90HP Johnson outboard motor. The symptom was the motor idled fine and ran fine up until about 3000RPMs then it acted like it was missing and would sputter, not getting above 3500 RPMs at full throttle. This happened even from a cold start. Turned out that one of the four carburetors had one loose bolt and one almost falling out. I tightened both and it runs fine at all RPMs now. I might add it would miss every 10 or 15 seconds at low RPM too. Just thought I'd pass this on to others.

 

[shadetree101]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Forget what I posted this morning. It still is not running right. I've had it with these American made outboards! This is the second boat I purchased in the last 3 years. The 1st boat had a Mercury Farce engine that self destructs every 4 hours. So in stead of doing what I should have done and put a Jap outboard on the 1st boat I instead parked it (still paying notes on it) and bought another boat with this Johnson. And now have to broken boats. Anyone what to take them off my hands real cheap??? email me. I get in my 12 year old Benz every morning an it starts right up. I wonder why outboard motors can't seem to last more than a year or two these days

 

[shadetree101]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

What I get out of this forum is:<br /><br />Whatever your problem is the solution is:<br /><br />"Could be anything"!

 

[ibm135]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

try changing your spark plugs.

 

[clanton]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

First you need to tell us the model number, there is a 60 degree model, a 90 degree model, could be a 2 stroke, 4 stroke, or injected 60 degree 2 stroke. I would do a visual inspection, then compression test, cold spark test. Then check for overheating. You found 2 loose bolts on a carb, what about the rest of the engine? Any alarms? Any lights on the system check gauge?

 

[whofan]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Sounds like a power pack starting to go. same thing happened to a coworkers motor same motor. After a little time his got progressefly worse.

 

[shadetree101]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

The motor is a 90HP, 60 degree model, 2 cycle.<br />Additional info:<br /><br />1. If I apply full throttle from idle it sounds like the prop is slipping or the motor is missing badly even below the 3000 rpm's I mentioned in the original post. If I slowly apply throttle it will only slightly miss before hitting 3000 rpm's then above 3000 it really starts running (missing)badly.<br /><br />2. When it is running badly I can pull all 4 plug wires (one at a time) and see only a drop of rpm's of a few hundred on all wires.<br /><br />3. Pumping the fuel bulb does nothing to help<br /><br />I'll try plugs but I don't see how they all failed all of a sudden. The boat was running fine and all of a sudden developed this problem.

 

[shadetree101]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Oh and NO alarms of any kind

 

[shadetree101]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

One other item I forgot to mention. When the motor developed this problem I remember hearing a rattling sound coming from somewhere on the engine. Not a real loud rattle but still some noise. <br /><br />Do these motors have problems with flywheel magnets coming off? Maybe thats the problem. However I don't have the special tools the manual calls for to remove the flywheel.

 

[shadetree101]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Ok yesterday I removed the flywheel and checked magnets. All were secure.<br /><br />I took the boat out again for a test to make sure I put everything back together properly. One interesting thing I noticed. I applied full throttle and the rpms came up to 5500 with no missing/lurching. Then about 10 to 20 seconds later it started acting like it was missing (original problem) and the RPM's went back down to 3500 and lurching. I raised the engine high with trim and the rpm's went to around 6500 with little movement of the boat (cavitating) as expected. I had to lower the throttle to around 1000 RPM to get the boat to move again. <br /><br />My question:<br /><br />Could this be a spun prop? Gearcase causing the problem?<br /><br />Thanks for any help<br /><br />I'm getting really sick of this problem.

 

[clanton]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Powerpack and sensor, but I would not replace them without checking output with meter, also check for coil arcing to metal plate that covers power pack.

 

[Hopsdak]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

I'd check your spark plug gap too. My '00 130 was giving me fits and running like crap.. Turned out to be the spark plugs were fouling out.

 

[shadetree101]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Thanks to all who respond to this Post.<br /><br />I'll change the spark plugs and gap soon as per your recommendations. I don't have a Peak voltmeter but do have an oscilloscope but was unable to get the reading the book calls for. I see spikes on the scope but they are no where near the required voltages. I may be check it wrong. Don't really know since I've never used my scope to measure these things.

 

[shadetree101]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

As I expected replacing the spark plugs made NO difference.<br /><br />Still runs fine for the 1st 5 or less minutes at 5000 rpm then goes to hell.<br /><br />Checked prop for slippage... NONE at all<br /><br />I hate boat motors!<br /><br />Anyone know of a good mechanic in or around Lago Vista Texas??<br /><br />I just want this dam thing fixed so I can sell it and be done forever with boat motors!

 

[shadetree101]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Also forgot to mention pumping the fuel bulb DOES NOT help.<br /><br />Removing engine cover and letting motor cool down DOES NOT help either

 

[billfishfla]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

shade <br /><br />I agree with you 10000000000% on Johnson products I have put over 2000.00 in a 70 hp 2000 engine and it is in the shop again this time the mechanic tells me it will be another 2000.00<br /><br />You might try to check your fuel line -- I had a pinhole leak in one of mine one time and it acted somewhat similar to waht you are descibing<br /><br />A pox on Bombardier

 

[clanton]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Where are You connected the scope leads?<br />Billfishfla, if you want a second opinion, see Gary at Outboard Repair on Pondella RD, North Ft Myers. He will not jerk you around, a quite talking man, that tells it like it is, and if he needs manuals to match your engine, he can use mine.

 

[billfishfla]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Clanton<br /><br />" Where are You connected the scope leads?"<br />what does this mean ?<br /><br />The boat is pulled already and Dolphin Marina has it<br /><br />Does he make house calls to other marinas

 

[clanton]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

The question about the scope leads was for Shadetree101. You will have to ask Gary about the house call. I make house calls, but I dont feel like getting involved with different mechanic. My blood pressure is better today doctor said, then it has been in 2 years, and I hope to keep it down, but I will take a look and give you my opinon. It will have to wait until late next week, mother in hosp for hip repair.

 

[DJ]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Bomabardier didn't build those engines. The bankrupt OMC did.<br /><br />Are you sure your engine is not going into S.L.O.W. mode to preserve it self from an overheat or oil starvation.