89 Polaris 340 sport engine help?

[Hench]

Anyone have any ideas on the following problem?

Polaris 340 fan cooled engine will only run on one cylinder. I have checked the non-firing side and has good spark all the way through the spark plug. Also verified it is getting fuel (plug is wet).

Other notes...

Compression tested fine in both cylinders

All new fuel line and new gas.

Removed carbs and cleaned well

Fuel pump seems to be working fine.

Tried it with and without the air box on.

I could tell the one side wasn't firing by feeling the plugs after driving it about 300 yards. One plug was hot the other cold.

Any help is greatly appreciated!!!

[sledhead]

What did the compression on the machine test at? More than 100 psig i hope.

A wet plug doesn't necessarly mean its getting gas. If it is still oil injected, which I'm assuming it is, oil is injected seperate of the fuel. Under some circumstances spark can blow out under compression. I did a top end for a fella with a 488 trail where everthing you listed was fine but the sled had cold siezed and lean burnt down but still got fuel but did not run on both cyclinders. just me 2 cents.

[Biggestfish]

Dead on what Sledhead posted, he beat me to posting the same thing. Neighbor had a 488 fan that the oil line fell off of and burnt down one cylinder.