Derestrict chinese scooter

[rag_angelo]

I recently bought a 50cc Chinsese scooter (Benzhou YY50QT with BZ139QMB). I've been reading a bit on how to derestrict scooters. I'm planning on doing the following:

- remove wacher on variator
- changing to lighter rollers (what weights?)
- changing contra springs (how hard or soft?)
- bigger carb jet (what size jet?)

(I took the exhaust off and it seems like its theres no washer in it that restricts it.)

Just wondering what you guys think of the things I'm planning to do. Is there anything else I should do or not do?

Thanks

[The Stranger]

Is there anything else I should do or not do?

Thanks

Twist the rubber band tighter.

[rag_angelo]

Twist the rubber band tighter.

What rubber band?

[bungbung]

Try googling "power band"

[blacksheep]

just leave it mate you will cause no ends of problems,if you want to go faster get a motorbike imho

[Jantar]

I must admit, that although I've been riding for more years than I care to remember, there are a few terms you use that I am completely unfamilar with. So rather than show my ignorance and ask "what is a xxxxxx?" I'll just make a few comments on getting the best out of the 2 stroke motor you have.

Some manfacturers do restrict the exhaust by fitting a washer type restricter between the exhaust and the exhaust port. You have already looked and there isn't one there. While you have the exhaust off clean off any carbon buildup in the exhaust system.

Don't change any jets unless there is a good reason to. A larger jet than optimum may give a small increase in power, measured in parts of a percent, but is more likely to give you an overrich mixture with colder running and fouled spark plugs.

Keep your spark plug clean and properly gapped.

That is about all you would want to do with a small engine that spends a lot of time at full throttle.

[rag_angelo]

I'm just using the scooter to go to uni anyways so its not really my main source of transport. Don't have a motorbike license too but planning to get a bike end of the year, just not right now. just looking to speed up the scoot abit so it doesnt feel so dangerous on the road.

[avgas]

Talk to NSRDan, he can get you the full derestriction kit. However it is all in vain as its not cheap and those scooters are POS 4-strokes.

[MisterD]

Don't lighten the variator weights - if you do manage to extract any more power, you would want to consider putting heavier ones in to raise the gearing, not lower it

[MisterD]

just leave it mate you will cause no ends of problems,if you want to go faster get a motorbike imho

But that would be boring and easy...you just need to start with a decent scooter.

[blacksheep]

But that would be boring and easy...you just need to start with a decent scooter.

alright if you have plenty of $$$$$$$$ to throw at it:rolleyes:

[rag_angelo]

Talk to NSRDan, he can get you the full derestriction kit. However it is all in vain as its not cheap and those scooters are POS 4-strokes.
POS?

Tried searching for NSRDan but I couldn't find that user name...


Don't lighten the variator weights - if you do manage to extract any more power, you would want to consider putting heavier ones in to raise the gearing, not lower it


Cool. What about the contra springs then, softer or stiffer? If I remember right, other sites suggested stiffer springs to give a lower gearing for going up hill (correct me if Im wrong please).

Also, I read that some scooters have an electronic restriction from the CDI (?) and the wire just needs to be removed, but I dont really wanna mess around with it coz I dunno which one it is :pinch:

[MisterD]

Cool. What about the contra springs then, softer or stiffer? If I remember right, other sites suggested stiffer springs to give a lower gearing for going up hill (correct me if Im wrong please).


Also probably not worth bothering with, unless you seriously change the power output of your scooter (ie up the cylinder capacity).

I put a 187cc kit and a PM pipe on my formerly 125cc ET4 and I changed the clutch and variator for Polini and Malossi items respectively then upgeared the final drive - didn't bother with the torque converter though.



Also, I read that some scooters have an electronic restriction from the CDI (?) and the wire just needs to be removed, but I dont really wanna mess around with it coz I dunno which one it is :pinch:

Yup, tis true. My (uk spec) ET is rev limited, which is a bugger - but a CDI change would mess with the imobiliser so I left it alone.

[rag_angelo]

Would anyone know which wire to remove on the CDI to take out the rev cut?

[Del Fuego]

I believe the wire cutting on the cdi you are talking about is to remove the top speed cut... does your scoot do over 50kmh now? if yes it probably doesn't have one.

I would ask the question on http://chinesescoots.forumwise.com/forum.html they seem to have a fairly good idea about the chinese stuff.

But yes, to confirm other comments there isn't really much to do with a 4stroke 50cc machine... they are pretty much just slow compared to a 2smoke :( even the good ones don't have much mambo even the Honda Today which is a nice bike is slow... and lacking a front disc