Plugs are fouling

[Kelly230]

I have a '98 Tourer and the plugs are fouling.  Carbs have been rebuilt (it was running rich at sea level, and really rich at 4700 feet where I live).  It does have 6 into 6 exhaust.  Runs strong, but the fouled plugs concern me.  We talked about rejetting it, but I've heard this is rarely done.

[shortleg]

  First thing check your air cleaner.
Found one at Inzane that had a nest
built by mice in it. I know it sounds strange
  The reason I say this is you talk like it is all
 of the plugs.
               Shortleg[Dave]

[Kelly230]

Actually, 4 are bad, one is a bit dirty, and the one near the vacuum line is clean.

[shortleg]

 Look at your plug wires and the cyclinder number
is on it.
  Sounds to me like you my have a carb problem.
Time to go in. You can find help here and our repair
manual.
               Shortleg[Dave]

[Patrick]

The vacuum line ?? There are actually 3 ,, but,, there are vacuum fittings on each intake.. So the clean plug near the 'vacuum line' may be caused by a defective vacuum line[cracked/split].. Where are the pilots set ?? At altitude they can set tighter[1/2 turn].. What needles are you using and where are they set?? You may try setting them tighter also if they are aftermarkets..

[Ricky-D]

I have a '98 Tourer and the plugs are fouling.  Carbs have been rebuilt (it was running rich at sea level, and really rich at 4700 feet where I live).  It does have 6 into 6 exhaust.  Runs strong, but the fouled plugs concern me.  We talked about rejetting it, but I've heard this is rarely done.

Are you the original owner?

Could be the previous owner has installed a lot of aftermarket parts in the carburetors which you are unaware.

A complete cataloging of whats there now would be important in trying to get to the bottom of the fouling problem.

How is the condition of the motor? Have you performed a compression test. This is the one test you should do especially in view of the fouling plugs.

***