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Sabre Tech & Modifications

Street-Rod Cool Twin-Plug Three-Valve Cylinder Heads Five-Speed Constant-Mesh Transmission Offset-Dual-Pin-Crankshaft Shaft Final Drive

Carburetor Synchronization

by Jay "Wislonghair" Duncan

Darn dealers soak you some good money for that 600 mile checkup on a new bike don't they? What do they really do to earn your money?? (around $120!)

  • Oil change with oil filter
  • Synchronize the carburetors
  • Check/Set idle
  • Check/Adjust cables
  • Check torque on nuts and bolts
  • Check tire pressures
  • Check air filter

Hmmm. Nothing you really couldn't do yourself is there? Get a 6 pack, grab your tools, and spend an hour in the garage. Run thru the bike and make sure everything is tight and still fits like it was new, then change your oil. It's easy if you've got a wrench that handles 2 1/2" filters. A Honda filter will set you back $11, and 4 quarts of Mobile 1 is just shy of $20. (Don't buy that Honda stuff!)

If you don't have tools, go buy some! Trust me, you'll still come in under budget, plus you'll have them for next time.

Ooops. Never did a carb sync? Lemme see if I can give you enough info to tackle it. It's not difficult at all and the money you save can be used to lay offerings at the Temple of Chrome.

First off you'll need a special tool. The one you'll see in the pictures is a older Motion Pro Deluxe Carb Tuner. They have a new verson, the Motion Pro SynchPRO Carb Tuner available now. If you look around the deluxe can be had for $79. Another nice looking gauge is the Morgan Cardtune II. It's worth having one because once you know how to do it, you can easily get that much in free beer by synching your friends bikes! If your friend rides a Yamaha, make sure you get the 6mm adapters, then slap your friend upside the head...
 

Yank the seat, yank the tank. There's only 3 bolts for the seat, two for the tank, and the main fuel line on the left side, and a breather hose under the tank on the right. Rig up a small gas can like you see in the pic. A male/male (icky!) adapter for an extra length of fuel line comes in handy. Check out that air filter while you're in there...
 

Find the vacuum hole in the intake manifold. (pic) Phillips head, and watch that washer! It'll try to fall off and hide. The 5mm adapters go in each side. (Don't attach the hoses to the Motion Pro gauge yet!)
 

Start up the bike with 1/2 choke if it's warm, more if it's cold. Let it get up to temp and leave the choke on a little. (The air sucking in the open adapter tubes makes the bike run lean, so you need the extra fuel.) Move the "vent tube" on the back of the gauge to "open". This allows air to replace the mercury that is drawn into the measuring tubes. You'll only need two of the lines from the gauge. (What's a guy need 4 cylinders for?!) Plug them into the adapters and walk around and see what the gauge is telling you! Do not touch the throttle. (You don't want your bike trying to run on mercury instead of petrol.) The mercury jumps around a bit so you have to average it out by eye, but the level should be close for each cylinder. If they're not you have to adjust.

OK. Adjusting the balance of the carbs is really easy on paper, but tough in reality! It's just the bolt/screw you have to turn, but it's hard to get to. I was able to use a really long flathead screwdriver, but "Lastone3" from the Sabre Group did a great job putting this tool together to reach it! (pic) I'll have a tool like that put together for the next time I do it. He says you don't have to pull the tank or seat with it, just the right front chrome fake head cover. (where's that bargain bin at Ace hardware!)
 

Turn the screw this way and that, and you'll see the gauge react. 1/4 turn will move the gauge quite a bit. It's nice to have the gauge hanging right off the grip 'cause you can watch it as you turn the balance screw. Once the thing looks pretty dialed, it's all good! Shut the bike down, take the adapters out and replace the screws. Slop the tank and seat back on, and you're dialed! Get on the phone, call your friends and say "YOU GOIN' ??" (tomorrow.... you've been drinking!)

That wasn't that hard now was it?

Item Cost
Tools Free?
Fuel line adapter  $1.00
Extra fuel line  $0.50
Motion Pro Gauge $42.00
Beer (domestic sure, but never Bud!)  $4.00
One hour not at "work" Cool!!
Total $47.50
Not throwing your money at the "stealer"? Priceless

Note to self: STP oil filter (p/n SMO-17) for the sabre at AutoZone for ~$6.00 (thanks mearnh!)

Disclaimer: Any person who decides to perform any of the above listed modifications, does so at their own risk.
The Sabre Group does not claim any responsibility for damage to your motorcycle or individual.