Different pulses out of the exhaust?

[irdave]

I noticed today that one of my exhausts has a much sharper pulse than the other. As in, when I put my hand behind the can, one feels sharp and the other feels a little softer...

Any ideas?

Thanks.

[Bill in OKC]

What kind of exhaust do you have on there? A throttle body balance might be in order. If that is good then I don't have any idea.

[irdave]

It's the Arrow SB 2 into 2.

Actually, I haven't checked the TB synch in a while, but this feels like a big difference.

Maybe I'll do a little synchin' tomorrow...

[Polux RSV]

The front cylinder has a more direct header than the rear wich have to turn back under the motor.

Angelo

[Scary]

All of the above & another is varying valve shim clearances one cylinder to the other can alter at what point the valves are completely closed, which in turn changes slightly the length of the compression stroke in each cylinder. The cam lobe comes into contact & out of contact with the shims at different points of the lobes lift ramp if the gaps differ. This is why some of us have gone to the extent of matching up all our shim gaps front & rear cylinders so they are all in the same point of the range, even in my case by getting a couple of sizes gound up special from a shim maker. It's going to extreme for the street but is done on race stuff most of the time... I would put it under the heading of "blueprinting". It smooths out twins enough to notice when riding. Just more extreme thoughts of mine. If it really worries u & none of the easy ones show it up, a compression test tells the story.

Ps....that leads to dialing in the cams, & on & on it goes into extremes.

Pss... & maybe the more direct header pipe has blowen more of the muffler packing out of that muffler as apposed to the other.