61x No Start- Waterbox Carnage!

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Fishman543

Location
Wapakoneta, Ohio
Hello, I came across a post written by JSS on Electrical system diag on Yamaha 701's. I am having an issue with the ski running, one day it sputtered and died, would not restart. Upon further inspection it did not have spark. It is a 1993 WB1, rebuilt SBT engine in 2017 along with a new CDI which appears to be for a 62T even though this is a 61X engine.

I checked out the coil and it had high resistance in the plug wires, I ordered a new one and installed, and boom I had spark again! The ski still would not start, it will back fire (blew waterbox apart) after 10-15 seconds of cranking, priming does not help. Never even tries to fire. I think I have something else going on. I followed the procedure for checking electrical system and here are the specs, all measured with a snap-on multi meter.

Charge coil 28 AC volts when cranking, resistance 240 ohms
Pulser coil 3 AC volts when cranking, resistance 14.8 ohms
Lighting coil 3 AC volts when cranking, no leak to ground (open), resistance is 1.10 ohms
Ignition coil is new aftermarket, resistance between wires is 11,000 ohms, primary coil measures .21 with the lead resistance subtracted. Old coil with no spark was 21,000 ohms between wires and .15 ohms on the primary.

Again, I currently have spark with spark plugs removed from head and grounded but something does not seem right. I realize most all of my readings provided are slightly off from ideal but find it hard to believe that everything is bad since the ski ran fine until it suddenly did not. All testing was done with a nearly new, fully charged battery.

Any help or suggestions will be appreciated.
 
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Fishman543

Location
Wapakoneta, Ohio
Will do! I pulled the front cover to look for anything obvious, did not see any timing marks on the flywheel or cases to match up. The flywheel is certainly tight with no play on the crank.
I'll pull the intake and check the reeds. The way it's acting is super odd. It's getting fuel in the right direction I believe since it's blowing up the water box and not out the intake. I would think the reeds are good but there is only one way to be sure and that's to pull and inspect.
 
Quinc

Quinc

Buy a Superjet
Location
California
Do you have an OEM CDI or a cheap one off amazon? Probably worth replacing the charge coil on the stator and the cdi. (oem only)
 
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Fishman543

Location
Wapakoneta, Ohio
Quinc said:
Do you have an OEM CDI or a cheap one off amazon? Probably worth replacing the charge coil on the stator and the cdi. (oem only)
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The cdi was replaced with a SBT brand along with the engine in 2017. I can't remember brand of it (Arieltek?) but it's not oem and it's not Amazon cheap either. I have a new cdi from Bay Area Powersports but it has an extra wire on it and I'm not sure what I would need to do to make it work properly yet.
 
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WFO Speedracer

WFO Speedracer

A lifetime ban is like a lifetime warranty !
Location
Alabama
Arielteks are junk CDI's I have replaced many of them , four things you want to be OEM are starters , stators , CDI boxes and starter solenoids.
 
Big Kahuna

Big Kahuna

Administrator
Location
Tuscaloosa, AL
Fishman543 said:
Will do! I pulled the front cover to look for anything obvious, did not see any timing marks on the flywheel or cases to match up. The flywheel is certainly tight with no play on the crank.
I'll pull the intake and check the reeds. The way it's acting is super odd. It's getting fuel in the right direction I believe since it's blowing up the water box and not out the intake. I would think the reeds are good but there is only one way to be sure and that's to pull and inspect.
Click to expand...
You have to pull the flywheel to see the timing marks on the stator....... You need to pull it to see if the flywheel key has sheared. If so, you will have spark, just at the wrong time and also "Boom" backfires due to igniting the fuel charge at the wrong time with the ports open........ Hense, your blown apart box.
 
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Fishman543

Location
Wapakoneta, Ohio
Slowly worked on the ski and as of today it's back up and running! Turns out that charge coil was the issue. It was just barely out of spec but enough to give it a weak spark and cause it not to run.

I pulled the flywheel as you all suggested and found Chinese stator, flywheel key was fine, timing was a bit retarded. Went ahead and ordered another Chinese knockoff before spending big money on an oem (not sure if they are even made anymore). Threw it all back together and it fired right up! Thank you all for your help and suggestions.

Still looking for a waterbox if anyone has one laying around that they don't need.
 
WFO Speedracer

WFO Speedracer

A lifetime ban is like a lifetime warranty !
Location
Alabama
Looking back at your first post the charge coil AC voltage needs to be around 35 VAC, I rarely rely on OHM checks and and more interested in the voltage output when diagnosing no start electrical issues.
 
F

Fishman543

Location
Wapakoneta, Ohio
WFO Speedracer said:
Looking back at your first post the charge coil AC voltage needs to be around 35 VAC, I rarely rely on OHM checks and and more interested in the voltage output when diagnosing no start electrical issues.
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The new was about 36, pretty crazy how much difference a few volts makes. The resistance was 380 vs 240 on the old one. This was my first experience diagnosing yamaha electronics and learned a lot. Past experience has been limited to seadoos....

I was prepared for a back fire this time, 2 sets of ear protection, safety glasses, ski in driveway vs garage. Was very surprised when it started up like it should this time.
 
WFO Speedracer

WFO Speedracer

A lifetime ban is like a lifetime warranty !
Location
Alabama
28 -36 volts is a huge difference as is 240-380 ohms, electrical stuff is precise if it's out of the acceptable range it either won't work or won't work properly.
 
WFO Speedracer

WFO Speedracer

A lifetime ban is like a lifetime warranty !
Location
Alabama
Kohldanielzimmer said:
Good thing you now have the knowledge on how to replace stators! You’ll probably replacing that one in short order but I hope your experience with the knock off electronics is different from most folks.
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Don't even get me started on Chinese electrics, when a customer comes in with a starting issue on a PWC or ATV it's one of the first questions I ask now.

I had a customer with electrical issues on his YFM 450, turns out he replaced the ignition switch and the starter solenoid with Chinese parts, unit wouldn't get power to anything, yep you guessed it I replaced both with OEM parts and haven't heard from him again.
 
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