77 polaris colt running on one cylinder

[peter p]

My 77 polaris 340 colt ss has good spark on both cylinders but only runs on one cylinder.
Could it be a blown head gasket?
I never did a compression test but what else may it be?

 

[longtrack156]

Good luck, I have an old Phazer engine that won't run on the right cyl, been playing at it for a couple of years can't find it, no luck here either.

 

[peter p]

We had the wrong plugs in it.
We had the BR9ES instead of BR8ES. Once we changed the plugs it fired up and is running ok.

 

[longtrack156]

Good deal!