Twinmax Carb Sync
 

Hi my question for today is anybody ever have used twinmax sync? I have hard time try to understand the function of it help ,please.

Yes, I've used one but it was a long time ago. Here's some directions copied from a website:

It is important on engines with more than two cylinders that you always balance all the cylinders against one which remains the reference or constant. Often there is one cylinder which is intended for this use-your manual will tell you this. It is suggested you use tube "A" for the reference cylinder. For good results, the engine should be near running temperature. On an air-cooled engine or a motorcycle it is advisable to sit a fan in front of the engine/bike to keep the exhaust pipes and motor cooled. On bikes, beware of exhaust pipes getting very hot and blistering nearby plastic fairings, etc. Keep an eye on engine temperature!

1. Ensure there is slack in the cable from the twistgrip or throttle pedal. If there is not a master idle screw, ensure all cable or rod adjusters have some free play-this makes sure that all carbs are sitting at idle, i.e., with their valves shut. Position the TWINMAX conveniently on the bike, such as on the saddle or on top of the frame and switch it on.

2. Connect the tubes to the carbs-one on the reference cylinder and the other on to one of the other carbs.

3. Turn the SENSITIVITY knob fully to MAXI.

4. Adjust the ZERO know until the meter needle is precisely through the middle of zero on the scale; this adjustment is very sensitive and very important.

5. Turn the SENSITIVITY knob back to MINI.

6. Start the engine and allow it to settle to a steady tickover. Don't be afraid of blipping the throttle-this makes certain the throttles are properly seated on their stops.

7. Slowly turn the SENSITIVITY knob until a deviation shows on the scale. The less out of balance the two cylinders being tested are, the more you will have to turn the SENSITIVITY knob to show an imbalance on the scale.

8. If there is present reference cylinder, quickly check each cylinder with one tube and choose the cylinder with the minimum deviation from zero on the scale as the reference cylinder.

9. Adjust the idle/slow running screw on the carb being adjusted (not the reference carb) until the meter shows an equal deviation on each size of zero. The meter is very sensitive, so care must be taken to use small increments of adjustment. Blip the throttle each time you make an adjustment to ensure the throttles are properly seated.

10. Repeat for all cylinders.

Once all the carbs are balanced at idle, they must next be balanced on throttle opening. As before, balance each carb against the reference cylinder.

Note that the balance must be checked as the throttle is opening and the engine is accelerating, NOT as the throttle is being closed and the revs are dropping. With some practice, you will be able to do this efficiently, and you will also be able to check the balance at a constant throttle opening.

You may find that a cylinder will balance fine on the opening up stage, but not on a constant opening; the skill lies in being able to interpret this and achieve a balance between one and the other.

11. Start with the SENSITIVITY knob about the middle of its' range. Run the engine and this time open the throttle gently and run the revs up to 3000 or 4000 rpm and make a note of any deviation on the scale; again, if it is not pronounced, increase the SENSITIVITY.

12. Now adjust the carb throttle actuator-this is either a cable or screw acting onto a plate or rod and may be hidden inside the carburetor top. Be careful to make only small adjustments. Note that if there are locking nuts on the adjusters, doing these up will affect the setting so double check the results and blip the throttle to settle things out.

13. Repeat for all the cylinders.

14. Adjust the slack in the cable from the twistgrip/pedal to manufacturer's specifications.

Yeh, I've got one...
 

Greg already posted the instructions. They are a bit more accurate than a good murcury vacuum gauge but their real advantage is being able to hook it up and ride. Observing readings at different throttle openings under load and then at idle after a run. When used in conjunction with an EGS/A-FR meter, its actually better than on a dyno.

Trying to set you fuel screws (pilot) with it or any such device on the VTR is almost impossible, you need to be on a dyno with a EGS/A-FR meter. Plumb the vacuum lines and plug them so you can sync without having to completely pull the tank; just tip the front up to get to the sync screw on the left side adjacent the rear carb.

Thanks Sirs i got it and it run very smooth w/oem replace air filter, next thing i m gona run dyno tomorrow($45) at local shop.

Wait until your year tire is shagged before doing a dyno, then replace the tires. I like the new Conti Sport attack front & Road Attack rear skins.

Why is that? Just replaced them not too long ago Dunlop 208

Tire manufacturer's do not warrant their product after a dyno run though I don't know how they'd prove you did one. Now if the dyno operator is careful and does not abuse your engine and drivetrain you might be OK; i.e., if they do not overheat the engine and tires. However, expect to loose about 1,000 miles worth of tread life from a meaningful dyno run, which will accelerate "squaring off" of the tread profile.

3 pulls on a dyno will not flatten the tire that much. If the bike had so much power that it was slipping on the coarse surface of the drum then maybe, but with only about 100hp I don't see it happening.

If its only 3 runs of short duration but thats usually only enough to set baselines. Extended tuning runs are hard on soft rubber. I've participated in many runs on different bikes and tires and checked tread wear before and after. I'm not saying don't do it but be aware it can easily happen, as it is not just slipage and weight in play here. I usually wait until my rear tire is about shot. A VTR's torque pulses provide not only good exits but also accelerated tire wear, more so than 4 cylinder engines. I'll bet you a six pack that 3 or 4 sets of 3 runs will skin 1,000 miles off a sticky bun.

Have a good and safe trip to NC, wish I could join U.

Yes, i got it done today 103hb and 65 fb and need to lower the clip 1down, 1/2 turn fuel screw seem like the plan to tear it up again. The rear tire ok, i do ask about manf warranty he said no, never and i bought them there.:o