Super Jet Help! Chasing Electrical Issue - Test Numbers Bad? VIDEO ADDED

Midlake Crisis

Midlake Crisis

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Location
Bakersfield, CA
I have my ski torn down yet again chasing an intermittent loss of high RPM. When the condition hits the motor will "brap" momentarily but when the throttle is held open it sounds like it is hitting the rev limiter, which has been removed, and won't rev past mid range.
I have "fixed" this problem several times, only to have the same symptoms return after a short time. Fixing exhaust leaks, replacing the carburetor, etc. I believe I have narrowed it down to being an electrical problem and have been attempting to test each component carefully to isolate the problem.

All of the battery and ground cables look and test excellent, with clean connections.

I did discover a break in the insulation of one of the green lighting coil wires inside the stator wire bundle sheath, about 1 foot from the eBox. I have repaired that wire but don't expect that that was the cause of the problem (?) since I understand its function is to charge the battery and is not directly related to the ignition system.

I have followed the tests described by Cosander in the FAQ section and have come up with the following values, with the spec range in ():

Charge coil output Br/W 31 volts (30-35)
resistance 361 (365 +/- 10%)
Pulser coil output W/R 4 volts (4-5)
resistance 16 (12.6-15.4)
Lighting coil output G/G 3.9v (6-10)
resistance 1.6 (1.14-1.4), isolated with no reading to ground
Ignition coil resistance Or/Bl.08 (.078-1.3)
Plug wires resistance 4.4k (3.5-4.7)

Any input is appreciated on whether any of these values are bad enough to indicate time for a JSS stator rebuild, or any other ideas anybody has. I am running a CDI with rev limiter removed but have tried it with another stock CDI with no change whatsoever.
 
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powerhouseperformance

powerhouseperformance

www.PHPSKI.com
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Location
wisconsin
Did you check to make sure the plug wires arent broke inside of the insulators? High rpm or high load missing is a common trait with that problem and its a pretty frequent problem.
 
#ZERO

#ZERO

Beach Bum
Location
Florida - U.S.A.
How do the plugs look?

If it sounds like it is hitting the rev limiter and won't rev past mid range you might have a short in your secondary ignition circuit meaning your high tension leads are grounding out somewhere. I'd replace the spark plugs and ignition coil & ends first and work backwards from there till the problems fixed. I'm guessing this is a 61X stator from your resistance readings and the lighting coil is just slightly higher which might affect your battery charging voltage.
 
Midlake Crisis

Midlake Crisis

Site Supporter
Location
Bakersfield, CA
powerhouseperformance said:
Whats the setup?...sounds like it might be rich on top possibly.
Click to expand...
61x cases /61x Jetworks ported cylinder
Stock reeds
Single stock SBN 44 carb
160 High
120 Low
22 popoff

I have the high and low speed screws both out about 3/4

#ZERO said:
How do the plugs look?
If it sounds like it is hitting the rev limiter and won't rev past mid range you might have a short in your secondary ignition circuit meaning your high tension leads are grounding out somewhere. I'd replace the spark plugs and ignition coil & ends first and work backwards from there till the problems fixed. I'm guessing this is a 61X stator from your resistance readings and the lighting coil is just slightly higher which might affect your battery charging voltage.
Click to expand...
New plugs, the old ones didn't look bad.
The coil is a JSS special from 8/11, last year I thought that would fix the problem but unfortunately it did not. The wires and boots are all in great shape and test good. And yes, it is a 61x stator and lightened 61x flywheel that would look very familiar to you!
 
Midlake Crisis

Midlake Crisis

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Location
Bakersfield, CA
#ZERO said:
Are you running the stock 61X CDI with the overheat sensor disconnected?
Click to expand...
The overheat sensor has been removed and the leads sealed. The CDI is a 62T with the rev limiter removed by CarterB.
I have tried it with a stock CDI with no change.
Is there any way the break in the green lighting coil wire was throwing the other systems off?
 
#ZERO

#ZERO

Beach Bum
Location
Florida - U.S.A.
That could be the problem you're running a 62T CDI with a 61X stator and flywheel combo which doesn't have enough AC voltage from the charging coil to operate the ignition unit. The 62T stator has a larger charge coil which puts out almost twice the voltage of the 6M6 or 61X to power the CDI. I'd find a 62T stator & flywheel or a 61X CDI to fix the problem.
 
Midlake Crisis

Midlake Crisis

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Location
Bakersfield, CA
#ZERO said:
That could be the problem you're running a 62T CDI with a 61X stator and flywheel combo which doesn't have enough AC voltage from the charging coil to operate the ignition unit. The 62T stator has a larger charge coil which puts out almost twice the voltage of the 6M6 or 61X to power the CDI. I'd find a 62T stator & flywheel or a 61X CDI to fix the problem.
Click to expand...
Makes sense - I think I have one out in my parts collection, will report back. Thanks for the idea!
 
Midlake Crisis

Midlake Crisis

Site Supporter
Location
Bakersfield, CA
Good news and bad news - ski ran awesome for about 6 minutes, lost power during WOT run, cruised to shore then wouldn't restart.
c129f748.jpg

14d53dad.jpg

I still think the problem is properly diagnosed (stator) but I guess I shouldn't have used anti-sieze on the FW bolt?
 
Pablo

Pablo

sqeez bth levrs & lean bk
Site Supporter
Location
georgia
I use anti-seize on all my flywheel bolts. I just make sure to triple check my torque specs before I close up the FW cover. That picture makes me cringe though. I hate it for you man. I'd go with new FW if it was me. "Ounce of prevention..."
 
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