[MotoCrazy]

So I been noticing like a popping from the left carb and I?m not exactly sure what it is... maybe a backfire going into the carb? Idk. I know it?s the left because I can see it move or almost bounce when the popping sound happens. On top of when I put my hands in both of the carbs while it does it , it is only the left one doing it...it?s kjnda of annoying and not to mention it will also do it while riding if holding the throttle steady and therefore it kinda upsets the bikes smoothness

any ideas as to what the problem might be?

 

[dtsmjr8dan]

What condition are your carb to head insulators? If you can see the carb moving when it backfires, I would think you have a vacuum leak in the insulator.

 

[MotoCrazy]

I wouldnt be surprised becuase i noticed that these carb boots were custom "fixed" with appears to be a double bubble like material beforehand...any idea if the orignals are even available anymore or is there a good subsitute? any idea what size i should be looking for?

 

[dtsmjr8dan]

I think they are still available. At least aftermarket is. It varies from time to time who has them in stock. Here's an offering from one of our sponsors. I've ordered stuff from them before. Good stuff, good service.
Scrambler Cycle - Honda 78-81 CB400T Carburetor Insulator Intake Boot Set 16211-413-000 - Reproduction

They also fit yours.

 

[MotoCrazy]

thanks! unfortunately it says its out of stock its a shame too since they seem like a decent price

 

[longdistancerider]

Google the part number and you'll find results 16211-413-000 INSULATOR, CARB $31.44