gp150 misfire help needed please now updated

[sunrisemac]

in my experience anything around 100psi at cranking speed should be good for most engines

[sunrisemac]

Hi sunrisemac
See thread Fri Sep 19 3;23pm compression kickover 105 pushing in second 110. my good scoot 95 and pushing in second 100psi
Thanks for your ideas
Grandpa

Just done a compression test on kickstart and i get just under 100psi with one healthy kick

[grandpa]

Hi sunrisemac,
Thanks for your compression reading.I did my innertube leak test overnight with no leaks.Barrel is off rings not broken and piston correct way round.Bought secondhand gp150 barrel and piston with no score marks from ebay will try that if it looks ok when it arrives.As you can see from previous posts I have tried stator,flywheel ht coil,ht lead,spark plug cap,different spark plugs carb, exhaust off good running scoot.new fuel at half a pint a minute plug is brown . Have run out of ideas.
Thanks for your help
grandpa

[sunrisemac]

Hi Grandpa, have you tried bypassing the ignition switch? I have looked after race cars in the past that have developed misfires when switches have rattled themselves apart internally.

[grandpa]

Hi Chaps,
This is now fixed. .I fitted second hand ebay barrel and piston with new rings new inlet manifold new carb and new points and condenser.Bearing in mind I had good compression (110psi) with orig barrel and had tried 2 other stators and the ht coil from my good running scoot I am wondering if I had air leak at higher revs from manifold carb junction.The original manifold was a poor casting and someone in India had used some thin metal to squeeze carb tighter onto manifold, but it did work before overhaul and the plug was brown.I always find it annoying to follow a thread but never find out the final result.
Thank you all for the many useful suggestions
Grandpa

[mcbrid]

Them pesky Indians!!!

[lammydave]

Them pesky Indians!!!

it's the cowboys you gotta worry about.....