Lack of power from pullaway and topend sym shark 125cc 2000 had new clutch and rollers and carb and belt slow in picking up speed geting 40mph topend was geting 60+

SOURCE: sym shark 50 cc won't start. Battery ok, but

have you checked the vacuum tap to see if its working simply remove the smaller diameter hose from the carb and the fuel line its self **** small one to create vacuum and fuel shold come from fuel line if not the tap could be just blocked or the diaprham could be damaged in the tap

Testimonial: "Thanks I'll check it tonight"

SOURCE: 2000 Yamaha TW 200 lacks power, has a high speed

Your timing may have skipped a tooth. This causes the glowing pipe. Ther are 3 positions that look like tdc. The flywheel has "I" "T" and range marks. This can be confusing. Put the "T" on the mark and you will run perfect. If not you can set it up one tooth or down one from that position. One setting makes the bike run like ****, the other one is barely noticeable more or less power. You may have to play with it a bit to get it right. If your pipe still glows after redoing your timing then your can change up your jet to a higher flow. Usually a performance filter will lean out the mix causing a red pipe. To much fuel just fouls the plug. I deleted my filter box and put a cone K&N filter. I had to jet my carbs to compensate for all the extra air flow. The bike had more power after I did this. The main jet I used was 127 or some where around there, the stock jet is 115 I think.

To much gas would never make you glow. Timing being off or being to lean will.

SOURCE: where can i get a sym husky 125cc workshop manual

http://www.repairmanualclub.com/motomanuals/index.php