Hi All, so here we go... Just had to do an engine swap put and did all the grunt work myself. Bike started up 1st time and sounded great, took it out for a ride and found she was having issues in the 4-5k Rev range and seemed to be heisting with a constant blurb note coming out of exhaust system, give it some more rev's and noise went away, gun her and she flies all the way up no problem, little bit of back fire when dropping off power (but do have a different exhaust on, so sure that does not hide the noise like a stock pipe). Took her in to a repair shop to get carbs cleaned, balanced & jet's checked to see if that would solve issue.. picked her up today and still same issue:crap: the repair shop is a good guy who I have used before! So looking for some advice on what may be the cause for the issue in the 4-5k band.. (1998 carb bike has K&N air filter, Jetted, After Market exhaust that all worked great on my other engine) like I said she goes like a bat out of hell under power but does not like cruising in the 3-5k rev range feels very rough.. Thanks..