2010 Ice Bear Trike ZH50 By grima (Read 4,203 times)

[grima]

Recently purchased an Ice Bear ZH50 which has had an erratic idle since I started it.

I put in new oil in both the motor and the rear end before I started, filled it with premium gasoline and checked all the wiring. Everything seemed fine. Started it up, ran for 5 seconds, then idle dropped and the unit stalled. By moving the idle up, I was able to keep it running, but the it still drops about 1000 rpm every 3-5 seconds. This is usually a sign of a vacuum leak, so I replaced all the lines and sprayed then entire motor with water to find a leak. No luck. I then took apart the air filter to the carb looking for a blockage. No luck. I took apart the carb, without removing the diaphragm for the needle or the acceleration pump. All passages and jets were clear. I checked the vacuum petcock, which is working fine. I checked the exhaust for leaks. No luck. I did a valve adjust, per the 139QMB manual (the engine which is in the unit). No luck. I suspected a lean condition, so I pulled the plug to see and found that the spark plug was black and dry, with a white condition only at the electrode.

I'm out of ideas at this point. I suspect an electrical problem, especially because my battery has died twice from all the idling I've done trying to diagnose this problem. I can get the engine started with the kick starter, but the idle will drop dramatically and kill the engine with the erratic idle. This is especially true when coming to a stop while driving. The trike has only 25 miles on it from diagnostic testing at less than 1/4 throttle.

Any help would be appreciated.

[Alleyoop]

Have you adjusted the Fuel Ratio Screw. When you say the idle is erratic is the idle bounceing up and down on you. Now when you first start it could the ENRICHER(CHOKE) is feeding it extra fuel and it should idle high around 2000 rpms or so. Then after 3-4 minutes the Idle should start to drop to where you have set it which should be around 1500-1800 rpms.

If the idle is bounceing IT IS Running Lean. Turn the Fuel Ratio screw Counter Clockwise and see if you can get the idle to Settle Down BUT only after 5 minutes so the Enricher Shuts off the Extra Fuel.
Alleyoop

[grima]

Indeed, I have tried using the a/f screw to enrich the mixtures. I have tried moving it out almost 3 turns, 1/8 turn at a time. Eventually, the unit just stalls, being too rich. All that happens is that the idle will go up slightly, in relation to the rises and falls, but it never evens out or even lessens the drops.

Spoke with one of the techs from the shop and he suggested replacing the electric choke. Going to send me new part under warranty.

[Alleyoop]

Yes, it could also be your choke. I took mine off and put on a manual choke on mine. In the summer time when first starting it it would always smell from gas Flooding it.
Alleyoop

[grima]

Think I've got it!

Replaced spark plug, was trying to arrange a photo for warranty replacement and decided to check the charging system. Found only battery voltage at all points with engine running. Disconnected the stator connection to the rectifier and the engine evened out instantly!

Stator is putting out 22V to the rectifier but nothing is getting to the battery. As the battery wore down, the uneven idle came back. So... stator or rectifier, I'm betting rectifier and changing my warranty request to that. Also going to see about getting a new battery since this one is FUBAR from all the testing I've done. Hope it will be under warranty.

Interesting factoid, though. The rectifier on my bike is a 5 pin type that my research indicates is for the 125-150cc bikes, while the 4 pin is standard for the 50. Got me to wondering if I reversed polarity on this thing, though. The two wires I disconnected went to a three pin connector. The white wire was connected to the rectifier. The yellow wire was connected to a green wire which was connected to ground (negative). The third unused wire was connected to the rectifier as well, but it didn't have a connection from the stator. I did notice that the rectifier is grounded not only to the frame but directly to negative as well. Not sure if this should be wired this way. From what I can tell, the 5th wire (black) from the rectifier isn't used. Not sure if wiring here is wrong or if I'm just not familiar enough to tell if it's right.

And before you ask, yes I tried connecting the yellow wire to the yellow connector on the rectifier and just got the same erratic idle.

Make sense to anyone else? I'm guessing the low voltage was causing a weak spark sometimes, which caused an erratic idle.

[sprocket]

Erratic idle has nothing to do with the rectifier regulator... it is direct AC from the stator to the CDI to the ignition coil...to the plug...

Sounds like it could be the pick-up coil or the CDI capacitors are NFG or a loose hi-tension lead, or a bad boot or a sick spark plug...

Check the voltage on the main lead going from the stator to the CDI.. should be somewhere between ~50 volts and about ~80 volts AC...

That voltage is constant.. the pick-up coil fires the spark...

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[grima]

Okay, how is this thing even RUNNING?! Thanks to Sprocket, I was able to find a wire that was out of place. Specifically, the yellow wire from the stator was connected directly to ground. After correcting that, the idle was still erratic so I checked for voltages on all four wires. CDI wire was only about 15V. White wire was only 1.2V. Yellow wire was .8V. Blue/black was pulsing, of course, but only about 1V. All measurements done in AC. Now I'm guessing that the stator is shot because someone connected the yellow wire (lighting system) directly to ground. Can't imagine how I'm going to get the stator off.

[sprocket]

I'm surprised it even ran with readings like that...but this is a 50cc so the voltages may be different than the drawing which is for a 150cc.
I would think they would be similar however...don't know.

Not that hard, but you need a flywheel puller. You also need an impact wrench to get the bolt off. There are other methods like using a breaker bar but they are a pain.

www.scrappydogscooters.com/Replacement_Parts.html

Stators come with a new pick-up coil so that should be replaced as well...

Problem is, you need to get the flywheel off to see what kind of stator you have. It could be 6 poles or 8 poles...you might be able to tell by putting a small wooden stick in the flywheel holes and count the poles that way...turn the fly wheel and every time the stick hits something it is a pole.. go all the way around 360 deg and you should get the pole number

Most likely 6 but could be 8.. then order a stator with the same coloured wires as yours has...

That way it is a straight swap...

[grima]

Waiting on a new stator and stator tool, but decided to investigate the rest of the engine for problems. Found a capped intake vacuum line and was wondering what it was for. Is it for a deceleration pump on a different carb? Or is it supposed to attach to the outlet on the EVAP canister (at least, that's what I suppose it is since when vacuum was applied, I got a lung full of gasoline vapors.) They are different sized connectors, so I assume not, but I just gotta know.

[grima]

Okay, this is getting irritating. Anyone have an alternative way to remove the stator? I used the tool from scrappy dog and turned it all the way in, turned the actuator half a turn and the tool popped right out, taking every last thread with it. Is there a thread chaser available? How about using the 4 screw holes on the outside edge of the rotor to push it off? Can I used a three jaw puller to pull it off? ANY suggestions appreciated. Going to search for a thread chaser now.

[Bashan]

Ouch, that's the nightmare scenario everybody dreads, like stripping the spark plug hole. My flywheel removal tool that I got from Buggy Parts NW has never failed me so I'm just speculating on a way around this. I'm not saying you got a bum tool, it may have been a defective flywheel. You have the center nut off right? I would think a three jaw puller is your best bet, the threads are toast. You're going to need a new flywheel anyway, don't worry about damaging the old one. Scrappy's got them for $25.00 about halfway down the link page. Ironically it's just above the puller. That puller looks OK, I doubt that it was the problem.

[sprocket]

You can use the screw holes to get it off, but the flywheel will be bent and must be replaced...

[grima]

Update for anyone who runs into this problem.

The 4 screw holes did not work for me. They merely demolished the stator (which was bad anyway, thank goodness) and then stripped the holes on the flywheel. I was finally able to remove the flywheel using a 3 jaw puller, which DEFINITELY bent the flywheel. So, if you run into this problem in the future, a 3 inch 3 jaw puller will do the job of getting it off. Just count on getting a new flywheel.

Incidentally, when it did finally come off, it came of explosively. Nearly broke my fingers. And I had to remove my exhaust to get clearance for the puller. Not what I consider a fun job. My wife is seriously put out with Ice Bear because of this. I've rather enjoyed honing my diagnostic skills, but a crossed wire on a brand new bike is more than a little irritating.

Thanks to all for the help. Keep safe!

[grima]

Okay, I've finally lost my temper. I installed the new stator and rotor (30 dollars down the drain) and the fricking thing is still doing it. Uneven idle (I've sprayed the piss out of it, no vacuum leak). I've checked the tank, running it without the cap on, even. I've checked the resistances across the cdi, pickup coil and excitor coil. All good. Changed the oil twice. Changed gasoline twice. Vacuum petcock is flowing fine. Fuel bowl is filling fine. After I replaced the stator and rotor, it looked like it was fine until the battery went dead again. Voltage out of the rectifier is only 12.4V at 6k rpm. At what it's calling idle, voltage output is only 12.2V. Is this right? It's my understanding that the stator and rotor should run this thing even without a battery, but it isn't.

I'm getting to the point where I'm ready to trash this piece of crap. Ice Bear may not be at fault, since Killer Motor Sports claims to have done a PDI on the motor themselves, but it's definitely getting out of hand.

[Cruiser]

You mentioned that the idle was smooth when you disconnected the regulator/rectifier. Then you found the miswire and a bad stator. You now have the same erratic idle now that everything is back together and you also have no charging output.

1. How are the output voltages on the new stator?

2. Did you replace the old regulator/rectifier?