New Student
Currently Offline
Posts: 5 
A+'s: 0
Joined: Aug 1, 2015 20:31:01 GMT -6
|
Post by jeffco on Aug 23, 2015 17:12:59 GMT -6
OK so the son has the thing for a week, and says it starts shaking real bad when he gives it gas and so, being an idiot, he decides it probably just needs more oil...and dumps a quart into it while on the side stand. Now I know the oil level was perfect a week ago, so he massively overfilled it. And of course it starts smoking to beat all hell when he starts the motor.
Thankfully at this point he calls me. I told him he probably just washed out the rings and ruined the motor, but first thing, since he has no tools and I'm 250 miles away, told him to lean it over with the cap off and dump out as much oil as possible, then refill correctly on center stand.
He did this after having a friend truck it home for him. He says that the smoke is subsiding now and the motor sounds pretty normal EXCEPT he noticed a couple of things.
Says there is a chirping noise now.
Says when you run it on the center stand, the back wheel does not move, even when you give it gas.
Says it does move fine when you get on it and ride, but hasn't tried to get up to speed because I told him not to ride until I get a look at it.
I'm just guessing, but I'm thinking the belt probably sheared a strand off or separated or something? That kinda fits the symptoms in my mind. Or something has gone wrong with one or the other variable pulley mechanisms.
One thing that may be a good clue: Remember I said it would "chatter" a bit (feel, not sound) on first engagement when cold? He said it had been doing that again.
Additionally...regardless of what else happens, I intend to go up there next weekend and try to figure it out. I only have one shot at bringing the correct belt with me, as I'll have to order it this week and take it with me. There won't be any available when I get there. So I have one shot at bringing the right one.
Far as I can tell, this is the same bike as the Znen Phoenix 150, it's a long case GY6(B?) with disc brake and 16" wheels. I feel that the most likely belt is the 906-22.5-30...can anyone verify?
|
|
New Student
Currently Offline
Posts: 5
A+'s: 0
Joined: Aug 1, 2015 20:31:01 GMT -6
|
Post by jeffco on Aug 9, 2015 10:04:11 GMT -6
I'm new to these as well. But in general, for a no-crank/no-start situation I'd be looking at the ignition switch, engine kill switch, and any safety interlocks it may have (like most full size motorcycles have sidestand engine kill switches, etc)...with motorcycles I'll usually find the problem in that trio of electrical parts, or the wiring between them.
With the ignition on and the engine cranking, there should be a continuous on-off-on pulse in the wiring between the CDI and the coil. Coil should have a continuous 12v supply, plus the switched path to ground that the CDI provides, if it works in a typical way.
I gather these use a magnetic coil type sensor to detect TDC and signal the CDI. If it goes bad the CDI will not produce a coil pulse. You should be able to see the signal from it with a meter set for very low DC volts.
As far as whether the CDI is involved with the starter I don't have any idea, sorry. But I kinda doubt it.
|
|
New Student
Currently Offline
Posts: 5
A+'s: 0
Joined: Aug 1, 2015 20:31:01 GMT -6
|
Post by jeffco on Aug 8, 2015 19:25:59 GMT -6
OK, bullseye on the vacuum petcock (or fuel cutoff valve or whatever you wanna call it). The manifold vacuum hose going to it was split, so it was getting enough suction to open and allow fuel flow, but at high throttle openings when vacuum drops it was trying to close off the fuel. This combined with the extra air the leak was passing made for a really lean condition at WOT, and it was clattering in response. It sounds very happy now and has much better pull. Hopefully the piston isn't cratered from this going on for a while. Who knows how long it's been this way.
I can't even figure how to access the air filter. The can sits sideways on top of the engine and under the fuel tank. It looks like the filter comes out through the right side and is a round can shaped element.
They obviously felt that nobody was ever going to have to work on these things. Or they didn't care. I can't yet fathom how to get to the headlight bulb either. I took some panels off trying today, and it was just snowballing so I packed it back up.
But while doing that I did find where the factory had misrouted and pinched the throttle cable between panels up in the dash area. Relieving that kink and pinch helped the excessively high idle.
Man these things are junky.
|
|
New Student
Currently Offline
Posts: 5
A+'s: 0
Joined: Aug 1, 2015 20:31:01 GMT -6
|
Post by jeffco on Aug 6, 2015 21:44:30 GMT -6
Thanks!
The turn signal problem was just that the center contact had gotten bent back too far to contact the base of the bulb. What a cheezy socket that is.
I bought some stick-on wheel weights and just as an opening shot I put two .25's opposite of the valve stem...just seemed like a good place to start. That helped immensely. The shake is almost gone. I'll maybe put one more on and see how it is. I had checked the stem bearings before I bought it, they checked good.
The rear brake, apparently somebody didn't understand the sequence of hardware as the turn signal is hung from the lever's pivot bolt...and they had the lever in a bind. Works fine now.
I haven't dug down to the motor yet, but the more I think about it, I'm betting I find a bad vacuum line. Do these have a vacuum petcock? That could explain a couple of things.
|
|
New Student
Currently Offline
Posts: 5
A+'s: 0
Joined: Aug 1, 2015 20:31:01 GMT -6
|
Post by jeffco on Aug 1, 2015 20:57:48 GMT -6
Long story short, I just bought this thing for my son who needed something bigger and faster than the 50s he's been slumming around on. It seems pretty nice, but has a few issues of concern to me. I have a about a week to fix them before I need to take it to him. I figured I'd toss it all out there, in case there are specific causes that you might recognize if familiar with these bikes.
The left front signal doesn't work. It's not the bulb.
The low beam headlight is out. I don't see an easy way to get to it.
The rear brake works, but the lever is very hard to squeeze.
The gauge needle illumination flickers and usually doesn't work.
It idles too high after warming up. It stalls at idle when cold.
It has a sound like detonation (spark knock) when you roll the throttle wide open while moving. It won't do it sitting still and running it against the brakes. Detonation will usually be very evident when you torque a vehicle up against the brakes, but not understanding exactly how these transmit load, it may just not be allowing that much load when not moving. Thoughts? Or it could just be a rattle from a muffler baffle or some other item banging around. I'd be more alarmed if it did it when starting up cold, like a bad rod bearing or piston slap, but it sounds fine otherwise. I guess I should mention I'm near 300 pounds, and probably quite a load for this bike.
It shakes pretty profoundly. Feels like the front tire is all hella out of balance. It has new tires. I see no weights. Will a 16" alloy wheel shake that bad on these? I cranked the rear spring preloads all the way up and it improved, but still annoying.
It has 5000 miles on it. Should I check/replace the drive belt?
If I look in there, is there something that should be done to the variator and rollers (clean, lube?). The seller told me the clutch drum engages harshly when cold. It did, until I rode it a couple hundred miles at high speed...it's been fine since. Thinking maybe something just got sticky from lack of use. What is considered minimum clutch shoe thickness?
Thanks for any input!
|
|
