how to synchronize your carburetors
Amsnow
To synchronize carbs using the mechanical method:
1. Place the snowmobile on a flat surface.
2. Remove the drive belt.
3. Remove the air box.
4. Set the parking brake.
5. Start the snowmobile and let idle until the rpm settle down.
6. Adjust the throttle cable free-play according to the snowmobile'sowner's manual.
7. Turn out each idle speed screw far enough so that it engagesthe slide.
8. Using one-eighth inch welding rods or coat hanger wire (cutto 6 to 8-inch lengths), squeeze the throttle, place a welding rod undereach slide and drop the slides onto the rods.
9. With the rods securely placed under the slides, crack the throttleslowly enough to raise the slides. Note which rod(s) moves first.
10. Adjust the throttle cable until the other rods move at thesame time as the first. Be aware that screwing in the adjuster will raisethe slide; screwing the adjuster out will lengthen the cable, thus loweringthe slide and reducing its response.
11. Remove the rods and tighten the jam nuts- not too tight.
12. Re-install the air box.
13. Re-install the belt.
14. Turn in the idle speed screws, equally turn-for-turn, as theengine idles, until the manufacturer specified engine idle speed is obtained.
If you are a "that's good-enough" type of a rider, the mechanicalsynchronization will do the job. But note that since each carb's airflowis not balanced, you have not achieved exact synchronization.
It may seem trivial to some to go this extreme to bring the carbs intosync, but your frustration level will decrease substantially. Never overlookthe little tunable items that make a big difference. As a side note, takethe time to read Olav Aaen's Carb Tuning Handbook and DynoTech for additionalcarb tuning information.
Many thanks to freelance tuners Eric "Wooley" Woolstenhumeand Gary Reynolds for their advice and patience.