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Post by cometman on Oct 20, 2010 7:36:33 GMT -6
In my first post, I talked about my 2007 150 w/2k miles on it.
It is a 157QMJ, I have a 5 min. ride to the gym in the morning and about once every 3 weeks, it will refuse to start after sitting hot for about 90 mins. This never happens cold. it will always take me there, but sometimes refuses to take me home, whenever I am done my workout, there is the anxiety about maybe having to walk home. I ruled out gas, I changed the gas valve anyway.
I have changed the CDI and the plug wire and coil also. Except for this periodic quirk, it runs great. Not sure where to go next on this. I need to mention that it always spins over,is not the battery or starter.
Also, what would cause a rubbing noise coming from the CVT in the back at the pulley, like it is rubbing on the cover?
Thanks, Cometman Tom
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Post by cometman on Oct 15, 2010 9:58:35 GMT -6
To adjust the valves, remove the valve cover and turn engine over until piston reaches TDC top dead center, you can do this by putting a socket on the flywheel and turning it until you see the markings or holes on the cam chain sprocket, they should be even with the head, at this point both valves should be completely closed, if you grab the rocker arms, you should be able to jiggle them a minute amount, if they do not move, they are too tight. I adjusted mine to .004 and they seem fine, not sure what the tech manual suggests.
Tom Cometman
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Post by cometman on Oct 15, 2010 8:42:53 GMT -6
Thanks Rich, It's great forum, I like reading the different storys, and getting advise, very informative.
I also have 2007 150 W/2k miles 157QMJ that has a not so often quirk, that I had mentioned in my first post, I changed some components and it hasn't done it for awile, still hasn't gained my trust yet, but we shall see.
Cometman Tom
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Post by cometman on Oct 14, 2010 17:29:20 GMT -6
I bought a 2006 Verucci 50cc 139QMB with 8k miles for $20 that wasn't running. It had spark and gas but would not fire, first compression check read 60, I pulled the engine expecting to do a top end, but found a tight intake valve which I then adj. to .004, rechecked compression got 150 reading, well within range. While pulling the back wheel I discovered that the drive shaft wheel nut was missing and the wheel moved over destroying the threads. I posted the question and somebody suggested to just re-thread it, I did, I made it 5/8x18 and it worked fine except for wanting to spin off. I drilled and put a cotter key through, problem solved. Put motor and wheel assembly back on and now running fine. $45. invested in bike, but needs a little more clean up. Thanks all for your advice, Cometman  |
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Post by cometman on Oct 12, 2010 9:52:09 GMT -6
My stock 150 w/2k miles logged tops out at 57 MPH, don't know what the revs are, tach went wacky.
Cometman
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Post by cometman on Oct 5, 2010 8:24:58 GMT -6
Great idea, that is what I am going to do.
Thanks, Tom Cometman
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Post by cometman on Oct 4, 2010 18:31:38 GMT -6
My 2006 50cc Verucci 139QMB that compression tested at 60. I found that the intake valve had no rocker clearance, so it must have been a minute amount open, I adjusted it to .004, retested and got a 150 reading. That problem seems solved.
I discovered while pulling the motor, that the rear hub nut was gone and the wheel moved onto the threads of the drive shaft and destroyed them.
This does not seem like a common combination, a 50cc on a large frame (150) size, giving it a long case, like a 150, any ideas on how to come buy the proper drive shaft would be helpful.
Thanks, Tom Cometman
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Post by cometman on Sept 29, 2010 10:29:40 GMT -6
I am getting ready to put a new top end on my 50, I think I will pull the motor, for ease and cleaning, everything works mechanically, but I think after 8k miles, it is tired of breathing properly, no longer will fire. I orded a compression tester, we shall see. I will continue to follow the Matrix. Tom Cometman
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Post by cometman on Sept 27, 2010 18:57:56 GMT -6
I bought a 2006 Verucci QMB139 50cc scooter, it has 8k miles on it.
It quit running on the previous owner so I got it cheap.
It spins over fine, it has good spark, but it won't even fire on a prime.
It gets gas, it is fresh, it stopped running 3 weeks ago.
Could it be lack of compression, maybe worn out?
Rocker arms and springs seem fine and open and close.
Would replacing the top end fix the problem?
What should the compression be and how do you check it?
I enjoy mechanics, any help would be appreciated.
Thanks, CM
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Post by cometman on Aug 26, 2010 18:25:55 GMT -6
I have a 2007 150 scooter w/GY6 157QMJ It always starts and runs flawlessly when started cold, if I ride it about a mile and let it sit for about an hour, it may or may not start again. When I come back hours later it will start right up like nothing ever happened. I imagine that I smell raw gas and it might start after grinding with full throttle open. This is a hard problem to diagnose because it never happens at home.
Any thoughts or ideas would greatly be appreciated.
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