So I've been riding my Hawk for two months now and am starting to notice something more and more. When I'm boulevard cruising in town, I usually find myself around 3,000 RPM. I don't look at my tach much, but I know this because right at 3,000 power goes flat and there's a mechanical knock (just one) that I hear and can feel through the tank. I've got Vance & Hines S4's but otherwise drivetrain is stock. New OEM air filter, 27K miles. WTF?

 

Brian here. I got my 03 VTR about 3 weeks ago after being absent from motorcycling for about 15 years. Prior to that I rode a Yamaha 400 Seca. My (now) wife and I put many miles on that bike, but it had to go with marriage and kids. Jump to age 40. The kids are still young, but I got the "go-ahead," and I jumped on it. -It's important to have that 996 cc's when giving rides though the neighborhood.
So now I've got my '03 with 6000 miles, great condition, high-rise Jardine pipes, but no after-market jetting. I couldn't be happier. I can't imagine a better bike for me. Any CCT, R/R issues I read about just make me look forward to getting my hands dirty in the garage this winter.
Nevertheless, I have the same issue. It's like a mild "chunk" at right around 3500 that you can feel in the tank. Mine often occur in pairs wich makes me wonder if it's carb timing. It seems to clear up after the engine is fully warmed up (210+).
A buddy of mine, who knows his bikes, rode it and said it was nothing compared to how his new KTM 990 Adventure behaves when it first gets going and that I shouldn't worry about it. His word is usually gospel, but I would prefer to know why it's happening and what I can do about it.

Anyway, thanks for having such a wealth of info. for such an awsome ride.
Brian

 

I'd say it's very likely to be carbs... that's a rather common place to have that problem... sync, remove pair and possibly shim/jet the carbs and it should be gone...

 

Barch (That's not Bachelor of Architecture, is it?) perfect description of the deal. After searching and reading some more, I'm finding that this is called "the dreaded hiccup" or some such. I think I might deal with jetting after I pay off my Wilbers... and fork rebuild... and R/R... and battery... and CCT's...

 

I also have a similar flat spot at about 4000-4500 rpms. No knock though, that i've noticed. the bike does lagg a little coming out of corners and definately does not have the power talked about on this forum. Mine is an '04 that you could likely say was abused by the PO. Vance Hines S4's, don't know about the jetting. doesn't seem to be any other mods. Sorry I am no help but i also have been out of it for a while and am just getting back in this year.