Cool kart!
Are you planning on competing at a track, or just riding it around for fun?
You can test-start your Methanol engine on gasoline, it'll run super rich and wont Idle very well, but It wont hurt anything to just test-start the engine. But don't ride it around that way, unless you convert the engine back over to run on gasoline.
Most guys that race methanol kart engines usually start their engines on gasoline for a couple minutes after each day of racing is over; to help flush all of the alcohol out of the pulse pump, fuel-lines & carburetor. Then they Immediately (& thoroughly) drain all of the engines oil -
while its still hot - so the moisture in the oil wont corrode the engines internal componets.
The reason for all this extra maintenance is: Methanol absorbs moisture from humidity in the air, and Methanol carbs are jetted super rich. Water in the Methanol will corrode the fuel system componets, and this super-rich mixture washes down past the piston rings and pollutes the engine oil with alcohol and water...
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Your karts chrome plated, steering column-support bars make it look like
it might just be one of the Invader brand models.
You'll find pics and info to help Identify Invader karts, (plus serveral other brands) at this site:
http://www.vdm46.com/invader-chassis-id.html
You could also email your pics to that site and ask Rod Van Deusen If he can help Identify it
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PS: I used to race a (methanol-fueled) Invader brand kart. Mine was a different model than yours, but you might dig checking out my old thread here at this link for lots more info:
http://www.diygokarts.com/vb/showthread.php?t=6364