Need help tuning walbro carby on small 2 stoke engine

[zacf86]

hey everyone, ive got one of those motorised mountain bike setups with a pretty decent engine and a chainsaw diaphram type carby as its better than the float bowl carbs you can buy for them( i think its a walbro, with low and high jet screws) and before you laugh cos of my silly bike, i have 2 busted shoulders and cant really ride big bikes anymore, and the motorised bikes are still fun and are cheap to run from A to B.
Anyway im basically looking for someone with solid engine/carby tuning knowledge that could help me tune my carb so it runs right cos at the moment its running way to rich and just 4 strokes a lot at WOT and doesnt seem 2 like going up hills much.
and it should chew up hills cos it used to before the weather changed.
and i probably went out of my league a bit with the carby setup i put on my bike as i cant tune it quite right with it being so fiddly.
i live up towards tea tree gully and golden grove in south australia, so if anyone is keen to give some advice or even come help in person as its a whole heap easier
( and that way i can also learn from what gets done ) that would be awesome.

cheers

 

[my67xr]

Welcome to Miniriders

You know Brenton don't you ?
I remember him asking me about this bike a while ago.

To lean off the top end turn the H screw in
When tuning whipper snippers etc, i hold it at WOT ( full throttle) and turn the screw in until it slows the engine a little, then back it out between 1/8 - 1/4 turn
then give them a decent run.

thius video helps explain the tuning too

[video=youtube;lsvq-11Y-Ak]https://www.youtube.com/watch?v=lsvq-11Y-Ak[/video]

 

[zacf86]

yeah he's my cousin. he told me to jump on here.

and i understand how i need to adjust the screws, the guy who made the engine has tried to help coach me through the steps but i just cant translate it to work on the bike.
and as for holding the throttle wide open to get max rpm so you can adjust the high needle, i dont feel confident enough to do that. i feel like im gonna blow up my engine lol.

the main prob im having is im pretty sure im not getting the low screw in the right position cos when i go uphill or take off from a slow start its a little non responsive and when you go over 1/4 throttle it splutters and doesnt transition to WOT smoothly unless im super gentle with the throttle, otherwise it just splutters. it still idles well when sitting and spark plug is more of a choc colour than a coffee colour so i know that its a bit rich.
but i just cant get the needles in the right spot, its either too rich or too lean so it would be way easier to fix in person while the engine is on the bike so you can feel how its working, if i can find someone with the know how thats nearby that is.
which is hard to find the help for because all motorbike shops just laugh or tell u they dont want to work on it. so my cuz said to try post someting here