Re jetting a jettex

[Bugracer69]

I have just put a tsr pipe on my go 200 with foam filter, however now it's now running like a sack of s**t !

I've been advised that I need to re-jet the carb - my current pilot is a 48 - main jet 135 - any advice on what the mix should be to get it to run better please ?

[rosscla]

When does it run bad?

135 sounds like a very big main.

[Chris in Margate]

135 is massive. Somewhere between 122 and 128.

[Bugracer69]

Hi
Was told to start at 48 pilot and work my way down from 130 main
It was fine to rev but when riding would cough and splutter mid rev range
So I pu t a 132 and it's the same but would sun better with choke on ?

[bristolmod]

as a start I'd go 50 pilot and 123 main then work the main up from there.

135 is way too big

Chris

[Daggs]

You don't say what carb you are using?
I think you'll need to look at the atomiser if mid-range is the problem.

[Bugracer69]

Hi
Yeah sorry it's the jetex22
After reading a post I about the atomiser I did take a drill to it and took the centre hole out to 2.0 mm
This made a massive improvement it still feels slightly better on choke
But now the bottom end seems to be flat where as before it seemed better ??

[Daggs]

Jetting a carb is basically trial and error.
I don't recommend drilling out atomisers, better to have a selection to try.
Make sure the scooter starts from cold with a bit of choke. Then start it from warm. If it's o/k? the pilot circuit will be there or thereabouts. Remember to set the airscrew when the engine is warm.
Then try riding it at half throttle. If it's bogs, the atomisers too rich. Keep trying different ones until it runs nice.
Finally move onto the main. Start with a 130 and do a plug chop off full throttle. If the plug is black and oily? too rich. Work down the main jets until the plug is brown.
It takes a while but gradually you'll get a feel for it.

[Chris in Margate]

Oh and unless you have a selection of jets at hand it starts getting expensive !

[Bugracer69]

Thanks for all your help and tips I will try to have a go at it today and see how I get on
Steve