roller weights and jet sizes

[tysxnsxnclxir]

hi I recently got my scooter licence and started playing around with my scooter (2011 TGB Tapo 50)since it wasn’t running right, I ran it too lean and blew it up.
Recently I upgraded to a 70cc big bore and it ran terrible topping out at 40kph and revving out quickly. I have done some research and found out that I have to upgrade the main jet, variator weights and clutch springs. I am ready to order the parts but wondering what would be the best size jet and weights, I read that if it is revving out too early to go for heavier weights.
Also I’m finding different answers to what weight the original rollers are.

[aeroxbud]

At 25mph I would think it is probably restricted with a ring in the variator. It stops the two halves closing together to give you a higher gear.
As to the jetting it will depend on lots of variables. Exhaust, cylinder, carb fitted and elevation for starters. Not all cylinder kits are the same, so it can vary.
Rollers are another variable I'm afraid. It all needs to match what you are using. If you have a sports pipe you might need lighter rollers than stock.
You can weigh them on a kitchen scales if you have nothing else. Just weigh them all at once, then divide by 6.
Somewhere between 5-6g is commonly used. For a sports setup.
You only really need clutch springs if you are getting a bog when pulling away. Though often with a street pipe the slightly stiffer springs help.

[tysxnsxnclxir]

hi thanks for the info, I have just weighed the rollers and they say 9g each on the kitchen scale, it may be rounded up because it doesn’t do decimal points. They also have flat spots on them, if the scooter is revving up but going slow do I increase the weight of them. Also on scooter street website it says they are 8g stock so I’m confused as to why they have 9g rollers. It has a very fast takeoff and power just no top end, this could also be fixed after I change the jet size. Also wondering if a contra spring upgrade would change anything

[tysxnsxnclxir]

Also it doesn’t have a ring to restrict it as it’s already been taken off and before I blew it up with the stock 50cc cylinder it was sitting on 60kph which it is limited to with the cdi

[Zino]

what brand 70 cc did you upgrade to ?
Some of the cheap 70 cc do not have the ability to rev out at a higher rpm than stock motors .
They just get you to top speed faster .

If you only changed to a low revving 70 cc kit you may not need to change the main jet since you are not running higher rpms .
What color is your plug ?
Darker is better
brown is best ,black is on the rich side

when you put on a kit you often need to drop the weights down since the extra power flings the weights out sooner causing you to shift sooner than needed.
get some weights in the 5 6 7 gram range and test them for best top speed and on off throttle responsive ness

If you kept the stock pipe you should not have to change the clutch springs
the contra spring should be fine and only replace it if you have belt slip.

[tysxnsxnclxir]

I’ve ordered a 10 pack of different jets which I will test, it is a cheap 70cc kit from eBay and I believe it is over heating as after testing it got very hot then made knocking sounds and died as if it blew up again then after cooling down starts back up again and revs up as normal, I think it isn’t getting enough fuel as it won’t rev up properly in the top end.

[tysxnsxnclxir]

Will check spark plug tomorrow but last I remember it was very dry

[aeroxbud]

Start off with a bigger jet than you think you need. Quite often for a sports cylinder 5-10% is enough. But it's better to go larger then work down. Less chance of damage.

[tysxnsxnclxir]

thanks will let you know how it goes

[tysxnsxnclxir]

So I got the new jets and tried a couple but it still smoking heaps and dies once it warms up, it still runs terrible and smoked no matter what jet I use, it sounds like the engine is struggling and I’m wondering if I have messed something up in the top end as sometimes there is some weird noises that could be knocking, I’m going to take the cylinder off and inspect tomorrow

[tysxnsxnclxir]

So got it running alright now but it’s still pretty hot after a few mins of running, just hope I don’t blow it up again