What are some signs that I may need to sync the carbs on my bike?

Question

1997 Yamaha YZF-750R. I have only been a rider since June of this year and the bike seems to run great. I am just curious as to what symptoms would indicate that the carbs would need syncing. Also, should I consider having them at least checked just to be sure?

Answer 1

All of the cylinders won't be running at low idle. Sync doesn't matter much when you have the throttle open, but if they're out, one cylinder will quit when you roll off the throttle while decelerating, and you can get some sputtering and neat backfiring.

Answer 2

well to check them, there is a basic vacume gauge that is used, you can purchase or just have the shop check for you every few years. Now if you bike was left over winter with gas in it and the carbs got corroded and had to be rebuilt, or if you put new exhaust pipes on (louder or hi performance, not if you just replace with same stock pipes) your carbs will have to be re-jeetted and sync checked, If you had other carb work done, notice that pipes are different colors (say 2 are blue and 2 never turned blue) these would indicate feul system might be out of adjustment and you need re syncing.

Now the good news....unless something like the above happens, you can go years without needing to worry about it. for the most part, once setup, they will stay that way !  enjoy  

Answer 3

Leave the carbs to the shop. If the bike is out of sync. It will run like c**p, won't start right.

Answer 4

Rough idle, stalling at idle, poor acceleration from a dead stop, popping or backfiring on deceleration are indications of carburetors needing to be synchronized.