Spark plugs - KLE400 vs KLE500
 

Since the first time I serviced my KLE400 myself I've always replaced the spark plugs with whatever the dealer gave me (ask for plugs for a KLE500). I have not had any issues and and it's even been on the dyno after I had a Stealth aftermarket pipe installed and the carb re-jetted (made 40hp atw :thumbup1: ). Now the question, I see you guys recommended not using the KLE500 plugs in a KLE400. Why?

KLE plugs
 

Hello Staal.

The heat range for the plugs are different for the 400 and 500. The 400 uses a slightly hotter plug, to combust properly. I went through the same issues, and found that the bike does perform better with the proper plugs.

Can you perhaps give us the details of the exhaust and carb upgrades you did, as well as the fuel consumption difference afterwards.

Just make sure that you tighten the plugs properly when you change them. The bike's plug spanner sometimes sticks against the top, making you think the plug is tight.

Regards