derestricting need help ?

[derekthedriver]

chutuma qt 50
i thought i'll derestict my bike as in the the guide posted there is no pink wire but a pink & white .the washer on the needle was already on the middle grove in the carb but where is the brass screw in the cap . there is no slip ring on the drive pully either .so has it already been deresticted . it reaches about 28 mph on the level ,but up hill between 15 to 20. have i missed anythink out to check..the bike starts first time runs great its just the speed i want sorting out .any pics to where exactley the brass screw is .or any more ideas to check .

[jason]

i got the same problem mate..what mileage you got?The only thing i did find was a pink wire but this didnt make much difference.Ive read that the shaft that goes through the roller housing should be 36mm long and if it is longer you will get slower speeds.But if youve got low mileage like me i woulnd worry if its running right.

[derekthedriver]

its only got 30 miles on the clock,it would be nice to go up hills a little faster than 15 mph.i had it a couple of months before i registed it,i started it up every day and let it run for a hour or so to losen it up .

cheers

[jason]

join the club mate seems like we are in the same boat.I got a little bit less on mine...just going to run it and see how it goes

[cb50j]

once you've got some Ks on the clock get lighter rollerweights, if top speeds don't get any better (your hill climbing speed definitly will) your scooters are restricted, it could be to do with the length of the "drive face boss" as scooter assassins call it.........

............ #sprint#

ps you can't run in an engine letting it tick over #no_no#

[jason]

can you just machine the drive face boss down to 36mm

[BillyGreen1973]

Yes you can just machine it down to 36-39mm. 39mm is the standard length.
You would be better measuring the length of your drive face boss first, just to make sure it is longer to start with.
The location of the brass screw is detailed in the derestriction guide, it should be screwed into the hole on the underside of the carb cover, there is a photo in the guide.

As for running in, if your bike isn't run in correctly, i.e. 20mph for the first 500km etc. then you will lose power. The break in procedure needs to be done 'under load', in other words, the bike needs to be working hard to make sure the piston rings make a tight and correct fit in the cylinder. Letting it run at tick over just wears away the honing on the cylinder wall and does not actually shape the rings, so when you come to put the bike under load (ride it), it cannot develop full power.

There are experts who believe a bike should be run in hard and fast, by running the bike at full throttle, under load, for the first few miles. Have a read of this article

mototuneusa.com/break_in_secrets.htm

I must admit, I didn't do the official break-in, I just went out and rode the bike as fast as I could from day one. I now get 45MPH no problem and can get around 55 down a slight hill.

[gaioshin]

I have a BenZhou YiYing (YY 50QT) which has a 139QMB engine. I have found exactly the same problem with mine - needle is set correctly (I even bought a new carb!), no ring on the variator, no apparent exhaust restriction, and only 5 wires (i.e. no electronic restriction) to the CDI unit. The carb main jet is an 80, which is not too bad.

I am only getting around 32mph with it on a flat. Not sure what's wrong with it thought. Haven't looked at this Drive Face Boss issue.

Again, as with everyone, if anyone knows how I may be able to alleviate this I will only be too happy to listen.

[jason]

my scoot gradually slowed down to 25mph..reset valve clearances and put 4.7g rollers in and now goes 40 and im 6ft and 14.5st...jay