Johnson gt 200 help

[Pres228]

I have a 1990 Johnson gt 200 that is giving me grief. I have rebuilt this engine and had it running great, then trouble. After the rebuild, I ran the motor for a break in time of 8-10 hours at varying speeds. All was running great. Now, however, the motor cranks, runs perfectly, planes off, then dies when the motor gets warm. It will then start, I can rev it up, but it dies when I put it in gear. I pump the bulb, no help to the condition while the motor is warm.
Background info:
Complete rebuild from block out.
New impeller with good water pressure. Heads are not hot at all when running.
New rings on all 6 cylinders. 80-81 psi on all 6 (I know that seems low, but is about average for this old looper)
All 6 carburetors have been rebuilt. I did not pay attention to the float position in rebuilding them. These are “non adjusting” carbs., and I am unsure I could have adjusted the floats. Also, the motor ran great for 8-10 hours after rebuild.
Link and sinc performed on carbs.
New gas. New gas lines. VRO removed.
New plugs.
Idle timing set at 6 atdc. Have not set WOT yet.
My timing light shows rpm until motor warms up, then stops as if no spark at all. While motor is running though.
The motor runs perfect at first. Then once warm, I put in gear, dies. Repeat.
I don’t want to just throw more money at this old motor. I hate to even mention this, but could it possibly be my stator? Any help is greatly appreciated.

 

[Faztbullet]

There is a difference between a rebuild and refresh...did you mike the cylinders or just slap rings in it. Compression is low for a rebuild

 

[Pres228]

My terminology might be off on what I call a rebuild. 6 new pistons, new rings, only honed the cylinders. My compression gauge is a rental and may be the lower readings cause. All are within 1psi, however. Also, the motor ran well during my “break in”. Appreciate any help.

 

[Pres228]

Update-
I started my motor with my timing light connected and on motor on muffs. All is fine for about ten minutes. When the motor warms up, the timing light will no longer show any signs of fire on any cylinder, yet the motor is running. I pulled the flywheel off and noticed a back coil looks like brown goo coming out of it. This coil has orange / orange black wires connected to it. Connected multimeter and the resistance is all over the place; it won’t settle on any measurement. The other brown/brown yellow wires are at 1000 ohms. Would this indicate a bad stator? Or could my power pack be bad? Again, motor runs like a top for ten minutes. Fuel supply is good also.

 

[boobie]

Yes, bad stator. May also have a bad power pack.

 

[Pres228]

Update again-
I have been looking and testing this stator and I am worried that it is NOT my problem. There is only a small amount of what appears to be an adhesive on one coil. Other than that, the stator looks fine. I rechecked my resistances and they are steady, and within specs. Timer base? Power pack? I am just stumped, and I certainly don’t want to make expensive guesses.
I have recently called a top quality local mechanic and he thinks my problem is in my carburetors. They have all recently been rebuilt, however. Also, the motor runs perfectly for about ten minutes before it starts failing and not running in gear. During this problem, I have re-pumped the bulb and pushed in key to see if fur is my problem. It does nothing different then. I have emptied gas tanks, installed new fuel lines, and removed VRO. I think that if my carburetors are my problem, why are there no sparks registering for me when this happens? Any help is greatly appreciated.
J200STLESE.

 

[racerone]

Is there a shift interrupter switch ?----The brown goo leaking from the stator is a fairly strong indication of problems.

 

[Pres228]

Yes. There is one directly under my shift linkage in the motor housing.

 

[Pres228]

I continue to check here for any information or replies. Thank you in advance for any information. I plan to check my shift interrupter switch this weekend. In the mean time, I have noticed how unbelievably expensive these parts are (timer base, stator, power pack). It appears that my problem is after the components warm up and I am trying my hardes to eliminate possible expensive guesses. Would a faulty timer base fail as my situation is described? Could a timer bases fail as motor is warmed?

 

[racerone]

Maybe test run with shift interrupt switch disabled.-------Your location ?-----Wide open throttle position is SET and very important.------The idle timing is where throttle plates OPEN.-----Actual idle timing when engine is running smooth does not matter !!

 

[Pres228]

I have the flywheel pulled right now so that I could get to the stator and timer base. I might try to change one or both of those (maybe used) before I put the flywheel back on and test the shift interrupt. My engine was running fine during my break in time, but I was fooling with my timing a bit. I had the idle timing set at 4 degrees ATDC. Immediately after putting the motor back together, I ran it with double the oil for 8-10 hours. This was a requirement in my SELOC manual and I followed the procedure closely. Towards the end of break in, I started running the motor back towards the 50:1 ratio. During that time I fooled with my idle timing again, and my carburetor link and sinc. I did this because I wanted a my idle set more towards 6 degrees ATDC, as recommended. It was during this shift back to 50:1, and my fooling with my idle timing, that the motor started to die in gear. If I put stator and flywheel back on right now, the motor will start, run, and plane off nicely. After about 10 minutes, it will die in gear. I can start it immediately back up, and rev it up, but as soon as I put it in gear, it dies. It is at that point that I can not register a spark on any wire with my timing light. Goodness, I am over communicating this with all of you and i am sorry. I have put a tremendous amount of work in this engine and I want to fix it right. Thank you much again.

 

[Pres228]

Even more info-
My stator has two different sets of brown/brown yellow wires connecting to the power pack. I just noticed that one of these brown wires has been pinched near the power pack. It is still connected, but pinched pretty good. Could this perhaps be my issue?

 

[Pres228]

[No message]

 

[Pres228]

This is a brown wire that connects my stator to my power pack. It has been pinched recently. Could this be my issue? Any information is greatly appreciated.

 

[rb215]

Hey did you ever get this problem fixed I have a gt200 that I have replaced just about every thing on motor and still have issues with this thing would love to talk with you about rebuild

 

[racerone]

rb215-----Just open a new thread.------Explain what your motor is doing / not doing.

 

[Pres228]

I hate that I missed these reply’s. Gosh, I should have followed up sooner.
i could spend hours writing about all that I have tried to figure out with this motor. I finally got it fixed last weekend.
The timing light that I was using was defective. A new timing light showed that my timing was set right and that all cylinders were firing. After many, many hours of work, I found that water was actually leaking in my number 6 cylinder.
Up to this point I have: reset carb bowls with new gaskets, swapped out stator, swapped out timing base, swapped out power pack, swapped out coils, swapped coil wires, new plugs, new gas lines. I have gone on and on for months. Luckily I found a parts motor for free within 20 miles of home. Very luckily. Other than my timing light mistake, I made a mistake when I first tested my compression. I never turn my motors over without water. Never. With good water pressure in this motor, it gave me equal pressures in all cylinders when I tested it. Therefore, I THINK the water gave me a false compression reading when there was a small leak at the head gasket. Therefore I did not think my problem was the head or head gasket. Turns out the head had some issues on the lower portion from a former piston loss. Installed “new to me” head, and new gaskets. Motor runs strong and now pushes my 21 foot stratos right at 60 mph.
I am so glad I did not give up on this engine. It may not last forever, but right now it is running well. Wish I would have followed up with the forum much sooner though.
pres228