carbs

[mjpxs11sh]

are there any links on carb sync. i put that phrase in search post and threads and nothing comes up! i borrowed a set of guages and fittings to start. i can see the 2 petcocks are an issue guess i have to get extended fuel lines even tho i have a mini bike fuel tank with diff line fittings.

[dbeardslee]

Carb sync is pretty simple. You've got three screws on the linkages to the butterflies. The one on the left hand side syncs carbs 1 and 2, the one on the right snycs carbs 3 and 4, and the one in the middle syncs 1 and 2 with 3 and 4. Warm up the motor and position a fan so it's blowing on the motor to keep it from overheating. Connect the vacuum hoses to the carb taps, set your petcocks on prime. Adjust carbs three and four so they're even, then sync 1 and 2, then sync 1 and 2 with 3 and 4. Try not to apply downward pressure on the sync screws when you make adjustments, and you might want to blip the throttle a little after each adjustment just to make sure you haven't pushed down on the linkage. You may have to go back and fourth several times to get them all at the same level. And that's just about all there is to syncing carbs.

It's usually easiest to do if you turn the tank around backwards and set it where the seat usually goes. A very long screwdriver works the best for me to get at the screws.

[DiverRay]

One thing is you SHOULD adjust the mixture if the carbs have been apart.
Link to sync:http://www.xs11.com/forum/showthread.php?t=75

[dbeardslee]

And one other thing - when you sync you want the motor running about 1100 rpms.

[dbeardslee]

And one other, other thing. If you're using a manometer with fluid or mercury be VERY careful with the throttle. My first sync gauge was that type, and if the vacuum gets too high it can suck the fluid/mercury out. Mine got trashed when I got a fart back through the carbs that sent gas into the fluid and contaminated it. Dial gauges or a Carbtune Pro are much better, IMHO>

[mjpxs11sh]

+

thanx doug and ray. i wanted a stick because ive read they are more accurate when a mechanic used both and compared the results on youtube. i dont have a tach ether to adjust mix. i didnt seperate the carbs when i cleaned them and installed new slow jets. bike runs good so its really just for experience. idk how you found that link ray but it explains what i wanted confirming like doug did. thanx again both of you!

[dbeardslee]

No sweat. As far as a manometer being more accurate than gauges - I'm dubious. I had a set of gauges that I made with Harbor Freight vacuum gauges, and as long as they were properly zeroed, they worked as well as anything else. A manometer may be a little easier to read, though. These days I use a Carbtune Pro. It's got the durability of gauges but you read it like a manometer, and you don't have to worry about fluid getting contaminated or sucked out. But they all work.

[skids]

thanx doug and ray. i wanted a stick because ive read they are more accurate when a mechanic used both and compared the results on youtube. i dont have a tach ether to adjust mix. i didnt seperate the carbs when i cleaned them and installed new slow jets. bike runs good so its really just for experience. idk how you found that link ray but it explains what i wanted confirming like doug did. thanx again both of you!

I like the Hg manometer sticks. You want to ensure that there is enough in the reservoir(s) so that the mercury does not drop below the inlet of the riser tube. If there is not enough an it starts drawing air, the fluid will keep rising up-over the top, and into the engine (don't ask). Also, If you rev the engine, let off the throttle slowly, because if you slam the throttle plates after reving, it can draw the mercury up-and-over. Don't forget about the toxicity of mercury. As a liquid it is pretty mundane, but if you vaporize it by blowing it out of your exhaust, you had better not breathe it!!!

[mjpxs11sh]

+

to reiterate im using dial guages. thanx guys

[DiverRay]

Just get a "T" fitting, and check that all 4 read the same before you do the sync. Mine go out now and then, and I check them because of that.

[motoman]

And one other thing - when you sync you want the motor running about 1100 rpms.

Actually idle is to be turned down in the 7-800rpm range whike setting fuel mixture FIRST using the 'lean drop' method, then a quick little sync, then get a floor fan in front of motor, leaving it on during your WHOLE tuning process.Now..............go back thru WHOLE process again in SAME order till a throttle 'blip with motor not running and THEN re-starting looking for any un-even vsavuum exist. When motor and you are satisfied, go for a ride putting different loads on motor at different rpm ranges, looking for faulty work by a so called mechanic.

[dbeardslee]

Actually idle is to be turned down in the 7-800rpm range whike setting fuel mixture FIRST using the 'lean drop' method, then a quick little sync, then get a floor fan in front of motor, leaving it on during your WHOLE tuning process.Now..............go back thru WHOLE process again in SAME order till a throttle 'blip with motor not running and THEN re-starting looking for any un-even vsavuum exist. When motor and you are satisfied, go for a ride putting different loads on motor at different rpm ranges, looking for faulty work by a so called mechanic.

9. Start the engine and let it warm up a little (approximately 1,100 rpm).

10. The carbs are synchronized if all have the same gauge readings.

Word for word, straight out of the Yamaha XS1100 Service Manual.