sounds like lean lsn masking to big idle gap. On mine it's hsn 1 turn in from flush,lsn is 1.25/1.5 turns in from flush. after the lsn is set then I recheck my idle gap. and reset. I use byrons 30% nitro with osp-3 plug. You may also have some blockage in the hsn inlet. I would take apart and flush out. Just to be safe. also make sure head and all other bolts are not loose.

Thanks for advice, can you explain what is the best way to flush out??

scurr,you might know me,dave g,i drive for go in the uk

try the OD97T plug as well.

on 25% the p3 works well but the 97T lasts longer.

mine is set so that the lsn is pretty crisp after 30-40 secs of warming up on the box with the top end stlll boggy,if its boggy on the lsn at this time and loading up then its too rich(for me anyways)

then tune the hsn on the track..its very sensitive to adjustment tho

Do you sometime race at Deerdale, I have just started racing at MMRX in Wakefield...
Tbh i went for the Go t3 plug because the engine seemed to be running well (only on my 2nd plug since new)

When i start mine on the box from cold it takes a while as I still think think the lsn is still too rich as the it seems to get fill with fuel, when i idle the engine it will take over for a min or so and doesnt seem to fill up a lot as I can normally throttle away no problems

[QUOTE=fastboy;7835552]scurr,you might know me,dave g,i drive for go in the uk

eye yes, I now remember the name from MMRX and also MSUK

ok heres teh deal, with 20% fuel what shimming should i use?

yes was there last week,finished 2nd in the A final.

i live 1 mile from the mmrx track

warm the engine upto race temp,so 5 mins of running on the track,then pinch the fuel line about 2 inch from carb,the revs should rise up after a couple of seconds then die..if it takes 4-5 seconds its too rich on the lsn

yes was there last week,finished 2nd in the A final.

i live 1 mile from the mmrx track

warm the engine upto race temp,so 5 mins of running on the track,then pinch the fuel line about 2 inch from carb,the revs should rise up after a couple of seconds then die..if it takes 4-5 seconds its too rich on the lsn[/QUOTE]

wow well done, I will be there on the 5th Sept at Deerdale so would be great to meet up and catch.
I was at MMRX on thursday and got soaked, what a mission to clean but was fun.

Check the idle gap. Read the tuning guide on the "Tech Tips" page of our web site at

www.go-racing.co.nz

This will explain everything. Unless your motor was purchased from the USA you should have the long needle carb fitted.
Sounds like you are too rich on the bottom and too lean on the top, due to an incorrect idle gap setting.

I won't say it, I'll just use initials.

AWT

Yep, she´s out walking the streets again

Maybe we should do some audio of Queens ¨Fat Bottomed Girls¨

Hi,

Could not get a Odonnel 97t plug but used a dynamite medium plug with my 7 port gx.
Tuned as per advice and the engine seemed to be ok, ran 3 rounds of heats of 5 mins and a 20 min final, engine cut with 1 min left and a third of a tank of 25% byrons,
found plug blown.
on checking the plug the wire was pushed up inside the plug.
engine temp after geting back to the pits from the opposite side of the track was 148 deg, car had caught under a hose when it cut out as the marshall was a bit slow.
Any idea why the wire is pushed up?

usually either a bit lean or you need another headshim.

would that be top or bottom too lean? shims are as standard with out extra shim fitted,
Where do you get your 97t plugs from Dave?

25% you should be fine with stock shims.
hard to say without seeing it,but i would richen the main needle an 1/8th and see how it goes.

ebay for plugs