So I have an 87 Tw200 and I have ridden it for 2 years now. The thing is starting to rack up the mileage(appx. 14,000). How many miles should it go before a rebuild? Are they re build able? And I have always had carb troubles with this bike. I have taken it to yamaha and they couldnt even get it right. I have re jetted, finely tuned, everything and it is still a jerk. Is it better to just get a new carb? What kind? Thanks!!