could rebore cause lean condition?

The engine in my xj750rh has been bored .020 over. I'm just wondering if that could cause a lean condition with the stock jets and pipes? I'm just thinking about the compression being a bit higher, not to mention the slightly larger displacement.
I don't have stock silencers at the moment though. They are the typical dunstall style widemouth megaphones from emgo.
The carbs have been rejetted to 124 but the top end is still lean from 5000 rpm on up. If I have the throttle pinned it will have a bit of hesitation. When I let the throttle back to 3/4 it will pick up on power a bit. What do you think?

 

The re-bore isn't the problem, but all the other non stock stuff is, once you start juggling all bets are off.

 

hmmm. I'm glad the pipes are the only thing not stock. I just can't believe they could cause that much of a difference to go from 120's to more than 124's. I think I'm going to experiment with larger jets an see what happens.
Aside from the lean condition at full throttle, the carbs work great! I'm thankful for that.

 

I would think so .......If the cyls have been bored, they are now bigger and want more fuel to fill them. If the carbs aren't supplying more fuel, then the mix would be lean...........

dave

 

748.6 stock cc's versus 760.2 cc's for the overbore

11.6 cc's, or 2.9 per cylinder, isn't much.

I'd bet on the non stock stuff.

 

"If I have the throttle pinned it will have a bit of hesitation. When I let the throttle back to 3/4 it will pick up on power a bit. What do you think?"
that's a sign of a lean mixture.
the bore didn't do it, the mufflers did.
can you change back to the old mufflers just to see if that's the problem

 

The stock mufflers were long gone before I acquired the bike. I would love to have the stock units, but they are like unobtainium.