I have 2007 suzuki intruder the front spark plug was replaced 3 times due to intermitant spark.Each time i check the spark plug no spark then replace the plug then spark then runs for short period the No 1 cyclinder no working check plug no spark ,Exhaust got extremely hot like glowing red also when run for long periods.

check ht lead is pressing against the spark plugs check the spark plug gap and replace ht leads and plugs if need be cheers

Check your CDI

I replaced the sparkplugs on mine two days ago. I took off the dummy tank (two parts) the central part (with speedometer) the aircleaner case. Then i took off the chrome cover on the right side of the front cilinder and the chrome cover on the left side of the second cilinder. underneath those chrome covers you will find the spark plugs. My intruder is from the year 03 but i don't think there's a difference because it is also carburated.