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Post by pnangled on Apr 18, 2009 19:54:31 GMT -5
ok so i got a gy6 clone engine. with a velocity mp 50 scooter.
its came crated from china and i changed all the fluids and got it running. but it will not go over about 20 mphs. and wont break 15 up a hill maybe even 10. so the first thing i did was replace the carb( the factory one was almost compleaty shot) and that seemed to only give me about 5 more mphs, maybe. ive been in touch with a tec rep from the place i bought it from and he seems to think that if it wasnt the carb its the stator. my question is one what possible reason could the stator have for not letting me go faster. also i should tell you guys that when its on the center stand it revs up big and the wheels seems to be flying. i get much more revs that way. but when i put my wieght on it about (140lbs) it just wont go fast at all.
the rep was kind enough to send me a brand new stator for a 139 qmb engine. i just wish there was something i was over looking or do you guys think i should just replace the stator anyway. in my opinion the stator has nothing to do with top speed. please tell me im wrong. also ive been all over this site and have tried a couple of things people have metioned. messing with the fuel mixture. (found rough spots while opening the trottle). i apppriciat any help you guys have to offer.
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Post by Skoot on Apr 18, 2009 20:20:05 GMT -5
Check the valve clearances. I would bet they are too tight.
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Post by tortoise on Apr 18, 2009 20:26:57 GMT -5
when its on the center stand it revs up big and the wheels seems to be flying. i get much more revs that way. but when i put my wieght on it about (140lbs) it just wont go fast at all. That often indicates a drive unit issue . . perhaps some hung-up variator rollers. But first check if the fuel-air mixture is too rich or lean by removing the spark plug and comparing it to this chart. |
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Post by Enviromoto on Apr 18, 2009 20:31:22 GMT -5
Weigh your rollers they may be to heavy.
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Post by cruiser66 on Apr 18, 2009 21:09:58 GMT -5
Welcome to ScootDawg, With the new carb, it sounds like you are reaching the max advertised speed - www.advatv.com/velocity-mp5005-p-96.htmlIn that case, you have a restricted scoot for sure. What rpms does the engine reach when you are at max speed? My scoot is very similar to yours and it hits 40 mph at about 7200 rpm. You might want to do a search on derestricting your scoot. 66 |
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Post by rapidjim on Apr 19, 2009 10:00:35 GMT -5
Another possiblity is that it came with a rev limiting CDI. Might want to ask the rep at the place you bought it.
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Post by Enviromoto on Apr 19, 2009 14:07:00 GMT -5
Sounds like the scooter is getting way up in the rpm band on the center stand but when the power is put to the ground it has problem switching into high gear. I have seen them put 8.5G rollers and carburetors without accelerator pumps to restrict them lately. Also the carburetors in the cheaper 50s seem to be having some issues as well.
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Post by cruiser66 on Apr 19, 2009 18:47:42 GMT -5
Yea, there are a lot of ways to restrict these scoots. This scoot does have a tach. That's why I asked about the rpms at top speed to help troubleshoot this prob. Still no answer.
66
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Post by pnangled on Apr 20, 2009 3:03:50 GMT -5
Sorry i havent been able to get back to you guys sooner. the problem is that my mp50 first off doesnt have a tac. www.countyimports.com/inc/sdetail/1098Thats the modle i have and it cleary states 50 mph. while i would take 40. I have looked at the forum for de-restricting the scoot. but so far all i have found is one post that talks about a pink wire. i have been able to find no pink wire on my scooter. i even found a post asking about which color theres might be and it didnt help me at all. id be willing to take a picture or list all the wireing if someone think they could spot the cdi wire that restrics it. also i would be willing to adjust the carb in order to make it work smoothly. also im sure considering the rep sent me a new carb and stator for free i could convince him to throw in a new cdi cosidering the trouble. thanks again for all your help guys. |
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Post by pnangled on Apr 20, 2009 3:09:06 GMT -5
also i found this but its not helping that much totalruckus.com/phpBB2/viewtopic.php?p=325396also i guess the next step is to check oout the roller weights. and maybe see if there is a restricting washer in the variator plate. |
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Post by rapidjim on Apr 20, 2009 7:26:00 GMT -5
You are correct it does state max spped of 50mph. That is not true. It is the same machine as Roketa and Tank sell and 50mph max is way off unless it has been modified.
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Post by rapidjim on Apr 20, 2009 9:09:25 GMT -5
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Post by pnangled on Apr 20, 2009 16:57:43 GMT -5
but see i found this www.bikezdirect.com/ProductDetails.asp?ProductCode=SCOOTER%2DMP50R&Show=TechSpecs and it calls it yet again something else and has a 50mph. im just going to assume its a china scooter with a qmb139 gy6 clone engine. and from my reading post it is possible to make these things run faster than 20 mph. ill get back to you guys about the rollers and soon as i can get on it. thanks again. |
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Post by cruiser66 on Apr 20, 2009 19:30:11 GMT -5
Sorry i havent been able to get back to you guys sooner. the problem is that my mp50 first off doesnt have a tac. www.countyimports.com/inc/sdetail/1098Thats the modle i have and it cleary states 50 mph. while i would take 40. I have looked at the forum for de-restricting the scoot. but so far all i have found is one post that talks about a pink wire. i have been able to find no pink wire on my scooter. i even found a post asking about which color theres might be and it didnt help me at all. id be willing to take a picture or list all the wireing if someone think they could spot the cdi wire that restrics it. also i would be willing to adjust the carb in order to make it work smoothly. also im sure considering the rep sent me a new carb and stator for free i could convince him to throw in a new cdi cosidering the trouble. thanks again for all your help guys. I'm confused in that the link you give is for a Roketa Sicily VM50 and you describe the scoot as a Velocity MP50. The Roketa certainly does not have a tach but the Velocity does.  Why do you call it a Velocity? 66 |
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Post by pnangled on Apr 21, 2009 16:21:55 GMT -5
the reason i call it a velocity is becasue it says that on the side of my scooter and right beside that it says mp 50. and as i said before it has no tac. any sugestions? oh also it calles it a velocity mp50 in the puny owners manual.
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Post by medman1952 on Apr 21, 2009 17:47:49 GMT -5
As you noticed the claim of 50mph is just not true, these little guys are lucky to hit 40 if they have no restrictions. I'd highly recommend that you do a 72cc big bore upgrade, you'll be much happier with it. Then change the sliders weights, upjet the carb, put a uniflow filter on and things will be ice.
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Post by stavros on May 18, 2009 1:56:08 GMT -5
Holy smokes! There's someone else out there who bought a "Velocity MP 50". It's a China machine made by Kaitong Motorcycle Manufacturing Co. It's max speed is 34 M.P.H. (I had to dig online for specs since it came with just a cheesy owners pamphlet) This is my first time on this site. I too have a slow machine. It'll do upper 20s to low 30s on level pavement and low 40s downgrade. ANY kind of an incline or headwind I cant go above 15 or 20. I blamed my 195 pounds.
Big bore 50 to 80 kit?
Different "roller/sliders" "which are better"? (what weight size for the stock 50 and "kitted" 80)
Different size spring in the drive? (what size)
Adj. valves?
I'll try almost anything short of installing a J.A.T.O. unit
Thanks.. I hope I get help.
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Post by crazyivan on May 18, 2009 10:55:16 GMT -5
i think it might be advertised as 50 KMH=31mph. many dishonest sellers will tell you that it goes 40-45, but thats just not true in most cases. my roketa went 40 on a flat, bbut it would take me a long ass time to get there. with enviromoto's stage 4 kit, im up to 50mph, and my acceleration is getting faster adn faster as everything is working itself into place
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Post by pnangled on Jun 6, 2009 17:21:42 GMT -5
Ok back from out of the country and im going to tackel this problem. now the first thing im going to check is the rollers. people keep telling me to change them but to what weight? i need to know which weight in order to order new ones online. if anyone knows that would be great
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Post by cruiser66 on Jun 6, 2009 20:40:05 GMT -5
Before you can figure out what to change the weights to, you have to find out what is installed on your scoot. You will have to weigh the actual roller. There is no set standard as to what the original weight is for a 50 cc or any other scoot and that's why you have to weigh them in order to determine what to order. Lighter riders can usually go with heavier than stock rollers while heavier riders might go with lighter rollers. 6.5 grams is a middle of the road weight for the 50 cc scoots. If your rollers are much lighter, then this could cause you to have a lower top speed, but it would help out acceleration.
66
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Post by steveo8309 on Jun 6, 2009 23:46:37 GMT -5
I had the same 20m[h problem out of my shenghi gmstar xy50qt with the gy6 clone engine and had my road runner at the same time identical scooters practically until i ripped both engines down after i locked up the road runner engine and found that the clone had a piston almost half the size with the same stroke crank so that might just be the problem i suggest upgrading to a 72 or 80cc big bore kit.
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Post by medman1952 on Jun 7, 2009 2:10:28 GMT -5
Other issues are an electronically restricting CDI. and things like restricted air intake or exhaust then there is the washer in the variator that keeps the two halves from coming together so it will not go faster than 30 mph.
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Post by lostintexas08 on Sept 18, 2009 6:11:45 GMT -5
is there a way to unlock a seized motor?
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Why do you call it a Velocity?
