Johnson GT200 drops 3 cyls when gets up to full-throttle

[Jwhit612]

I have an '88 Johnson GT on my '89 Glastron Futura 200.
I just got off the phone with my mechanic and am starting to get worried. When I first take off, as long as I ease it up, it jumps right up on plane but when I push it to full throttle right away or after it is running it drops 3 cylinders all at once and will throttle all the way down and die. Anything above 2/3 throttle or so will cause this annoying behavior.
When it drops 3 cylinders I can throttle it back to neutral and it will idle out fine, then I can take off again.
My mechanic just told me that he has spent 3-4 hours on it and hasn't been able to isolate the problem yet. He is confident though that it is in the ignition and he says once you replace one portion of the ignition then you might as well plan on replacing it all which will run around $1,100.
So a couple of questions. One, any ideas on what would cause that? And two, is what he is saying correct about replacing the entire ignition system? I have only owned this boat for a couple of months and am hoping I didn't buy a black hole.
Also,the reverse doesn't work for some reason. when you put it in reverse it revs up but doesn't engage. He said he is guessing it will at least need a new gear set which will be aprox $600 more. Would you suggest buying a used lower unit or putting a new gear set in it?

Thanks in advance for your help! You guys are a huge help to a novice like me.

Thanks again,
Jeff

 

[baiwan]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

Replace the power pack of the three cylinders that drop and try to adjust the cables that control the gear shift lever, and if this doesn't help which I doubt try another mechanic.

 

[nymack66]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

Simply swap the power packs around on the engine and see if the problems moves with it this way you know for sure if its the pack. I thinking SLOW (do a search) should me looked at since it could be overheating.
As for LU buy and use one on Ebay or craigs much cheaper and keep the current one for spare or sell it for parts.
As for your mechanic ideas in regards to replacing it all to me its mind boggling that's all I am going to say for now.

 

[daselbee]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

I agree with Andrew regarding the replacing of all those parts. Just crazy to do...I think he is looking for a patsy...

You have a shift switch on the starboard side that is designed to kill 3 cylinders only momentarily when shifting. Just disconnect that harness up at the pack area and re-try. Should be a black/yellow wire to the pack that you would disconnect. On shop.evinrude.com drilling down to your motor, and on the cylinder/crankcase page, it is part ref number 98. Down low below the carb level on the starboard side.

Also, disconnect the shift cable at the engine and manually shift the engine when running and on muffs. If it shifts OK then, your cables are needing adjustment. If not cables, possibly the shift shaft height. Watch your foot for spinning prop.

It sounds as if your cables are way out of adjustment.

 

[SparkieBoat]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

intermittent electrical problems can be time consuming to figure out. I like the swap the power pack idea and see if the problem follows the power pack, if it does not it may be the stator. I would also bypass the thing daselbee mentioned..even though I never heard of it before. if you can find a good used foot for under $300 that someone will guarantee not to be DOA and doesnt leak....that may be a good way to go. check cable adjustment first though. $600 is not bad to replace the clutch dog and reverse gear, he should also replace the seals while he has it apart.. request only genuine OMC parts though...no cheap after market gears, I have heard they are substandard. also make sure your cables are properly adjusted after wards, this is the main cause for stripping the gears. If all of the electrical components are the original parts, it may not be all that bad to replace them all, It could save you from having a power pack or coil go out on the 4th of July when your trying to pull your kids on a tube and no parts places are open.( happened to me last year...lol)

 

[Faztbullet]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

Shift switch or going into slow but if its in slow mode it usually needs a couple of minutes to cool or a restart to reset. If it is missing and stuttering when it does this disconnect rectifier and retry as I have had 2 of these this year do this and rectifier tested good.

 

[jonesg]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

I have an '88 Johnson GT on my '89 Glastron Futura 200.
I just got off the phone with my mechanic and am starting to get worried. When I first take off, as long as I ease it up, it jumps right up on plane but when I push it to full throttle right away or after it is running it drops 3 cylinders all at once and will throttle all the way down and die. Anything above 2/3 throttle or so will cause this annoying behavior.
When it drops 3 cylinders I can throttle it back to neutral and it will idle out fine, then I can take off again.
My mechanic just told me that he has spent 3-4 hours on it and hasn't been able to isolate the problem yet. He is confident though that it is in the ignition and he says once you replace one portion of the ignition then you might as well plan on replacing it all which will run around $1,100.
So a couple of questions. One, any ideas on what would cause that? And two, is what he is saying correct about replacing the entire ignition system? I have only owned this boat for a couple of months and am hoping I didn't buy a black hole.
Also,the reverse doesn't work for some reason. when you put it in reverse it revs up but doesn't engage. He said he is guessing it will at least need a new gear set which will be aprox $600 more. Would you suggest buying a used lower unit or putting a new gear set in it?

Thanks in advance for your help! You guys are a huge help to a novice like me.

Thanks again,
Jeff

He's not a mechanic. HE is guessing.

 

[Jwhit612]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

Thanks guys. Very helpful. I'll stop by his shop today and talk through some of this stuff. This guy also tends to speak in hyperbole so maybe he is making it sound worse than it is. I wish I had a better mechanic around here. I'm in Greenville SC. Let me know if you know of any in my area.

 

[SparkieBoat]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

should be plenty of outboard shops around greenville..nice lake up there

 

[ezeke]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

Some of the 1988 loopers had problems with the temperature switches which can cause any or all of your symptoms. See Service Bulletin 2196.

 

[Jwhit612]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

Ezeke, sorry to sound like an idiot but what is Service Bulletin 2196? How do I find that?

 

[ezeke]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

Ezeke, sorry to sound like an idiot but what is Service Bulletin 2196? How do I find that?

Your service department should have it.

BTW, you should only have one powerpack so you cannot "swap" them.

 

[Jwhit612]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

Very late update but it turned out to be a combination of the stator and timing.
Thanks for everyone's input.

 

[SparkieBoat]

Re: Johnson GT200 drops 3 cyls when gets up to full-throttle

glad to hear you got it fixed...I have since then learned how to trouble shoot stator/powerpack with a DVA adapter..I can now troubleshoot an engines electronics in just a few minuets..all my friends with outboards now love me...LOL