Plug Fouling

[Steveuk56]

Hi, Hoping for a bit of help /guidance I have a 1975 GT500 , my only 2 stoke and I just can get it to run right, the right hand plug continually fouls/oils up.
With a new set of plugs it starts 1st or 2nd kick and runs great, choke off virtually straight away. First couple of miles it runs great then a bit of a misfire on the R/H cylinder after another couple miles total failure on the right hand plug, taken out its totally wet with petrol and possibly oil.

What I've tried , stripped and cleaned the carb 3 times, replaced leads ,caps and the coil. Checked compression which was 105 PSI ( same on left )

What suggestions going forward, what should I check / replace and in what order. Love to ride the bike more than a couple of miles.

Thanks for your help - SW

[karl pa]

Does it smoke excessively ?
Does the gearbox oil level drop ?

[Steveuk56]

Its only smokey with choke, once its off not that smokey at all

[karl pa]

What size jets are in carbs ?
Float height correct ? Does float shutoff fuel flow ?
Does it have the PEI ignition or points ?

[Steveuk56]

Hi , It’s PEi ignition, carb does shut off assume that it would run out the vent if flooding, I haven’t checked the flow height, not sure to on this type of carb, would be similar to checking an Amal float height ?

[karl pa]

I remove bowl, hold carb upside down, hold float so it just touches spring plunger of needle valve, float arm should be parallel to carb body.
Another thing to check is the choke plungers are sealing when closed.
You mentioned you can close choke right away, my 76 GT500 takes a minute, that makes me think yours is running rich.

[Steveuk56]

Thanks , I’ll check those