Motorcycle Repair: Cold Weather runs poorly, cylinder compression, cold weather


Question
My '96 FLHT-Police will not run at temps below about 45F.  
It will start, but backfires (both carb and exhaust), fouls
plugs, idles poorly, etc.  Above about 50 it seems to run
fine and will burn off plugs and go like a dream.  I've had 3
shops into the carb.  Replaced intake seals and slider,
adjusted, etc.  Can't find anything in carb.  I just replaced
ignition module.  Still same problem.  Compression
apparently OK.  Going out West in spring and don't want to
be caught on mountainside.

Answer
Hi Nelson,

Can you describe the appearance of the spark plugs when fouled?

Did or does engine run better with choke or without choke in -45 degrees?

What tpye of air filter is in use?

What jets are installed now?

What is the elevation and average temperature where you ride?

What are shop techs saying about the problem?

Do you know what cylinder compression readings were? Was a leak down performed?

Reply to these questions and we'll go from there. I return tech files by email. Be sure to include your email addy with your reply.

Respectfully,
Mark Shively