[Bill283]

I can hear a thumping noise coming from the Air Suction Valve while the engine is running. Closing off the small vacuum hose leading to the ASV, the thumping stops. Is this normal? I pulled the small vacuum hose off the carb port and hooked up my hand vacuum pump and the ASV held vacuum. Is this why some of you guys are 'coastering'?
Thanks,
Bill

 

[VN750Rider/Jerry]

I totally and completely recommend removing the entire air injection system. It serves no purpose, and can cause rideability problems, overheating exhaust, and, as you found out, noises. I doubt very many members who have been here very long still have their's. While I don't recommend doing the "earshave " thing, or removing the "goats belly" or punching out the baffles in the pipes, all of which have negative consequences, removing the air injection has no negative side effects, and will get rid of a ton of worthless junk from your bike. I removed mine within 2 months of buying the bike new, 9 years ago.

 

[Bill283]

Thanks Jerry

Jerry, thanks for the quick reply to my question. The bike is not mine, but is a friends new (used) purchace. We are learning quite a bit about VN750s. This forum is great for us newbies.
Bill283