First time carb sync

[maximark]

Hi all, I've purchased Motion Pro synchronizer and planning on syncing carbs on my 94 ST1100. There are instruction in service manual, Haynes book and on synchronizer package.
First of all, should syncing be done on worm ( what make sense ) engine?
Any tips or tricks would be appreciated.
thank you
Mark

 

[Mark]

I do my syncs on a cold engine... don't know why, I just always have... it might be because I was taught that way... so I'm watching for a definitive answer too!

 

[Basic]

If there are different values between cold and warm engine, then it seems logical to do it on a warm engine. I believe it is even recommended to warm up first and place a ventilator in front of the radiator to prevent overheating.
Also it might make a considerable difference whether you have the airfilter in place or not. So, tune, with the airfilter in place.
A flashlight might prove helpful to locate the adjusting screws.

Regards, Rob

 

[GitSum]

Ok - I had a link posted that I felt was good for the overall procedure, but as John O pointed out in Post #10, there was an error in the actual methodology. (All carbs should be balanced to the #4 carb which is the left rear)

To avoid any further confusion, I have deleted the link...

 

[Mark]

I have noted that you also have to have a very 'light' hand on the adjusting screws or the rpms will vary when you lift the screwdriver.

I think I'll switch to 'warm engine' the next time.

Thanks!
Mark

 

[Uncle Phil]

I usually let the 'girls' warm up before I sync them since they'll be 'warm' when I'm running them! But I use the SK Flowmeter which is a lot less work. It takes longer to remove the bodywork than it does to sync them using that lovely tool! ;-)

 

[userzero]

I have noted that you also have to have a very 'light' hand on the adjusting screws or the rpms will vary when you lift the screwdriver.

I agree : real light! And lots of patience.

 

[IpswichST]

I noticed when you do the adjustment you need to give it time to settle down. Just pushing on the screw head will make them race. And small adjustments

I used my own homemade manometer... I would like to try a store bought one to see how accurate my homemade one was.

Good luck

 

[maximark]

I noticed when you do the adjustment you need to give it time to settle down. Just pushing on the screw head will make them race. And small adjustments

I used my own homemade manometer... I would like to try a store bought one to see how accurate my homemade one was.

Good luck

Once I'm done with my carbs, I'll post my Motion Pro for loan.

 

[John OoSTerhuis]

Here is a good link on the subject:

http://www.st-1100.com/carburettor-balancing.html

N.B. there's a serious error in that link!!! This is the same error published in the Haynes manual which we have known about for years!!

Balance each of the other three carbs to the base carb (#4, left rear) individually in any order. The #3 carb screw adjusts that carb and only that carb... period! That screw has no connection nor any effect on the other carbs, individually or as a cylinder head/bank!

Sheeesh... Don't let this crap propagate any further!! It's screwed up enough ST1100 owners over the years!!

John

 

[IpswichST]

I read that link and thought I had done it incorrectly. I had read that you balance all carbs to #4 individually... which is what I did. Here is a case where this message board has proved to be more knowledgeable than the printed material on the same subject!

 

[Fred Lloyd]

Motion Pro has a tutorial YouTube video on how to set up and use their sync tool. Here's the link: http://www.youtube.com/watch?v=2nwP6R1P58A

 

[maximark]

I read that link and thought I had done it incorrectly. I had read that you balance all carbs to #4 individually... which is what I did. Here is a case where this message board has proved to be more knowledgeable than the printed material on the same subject!

+1 to that. Sometime I feel weird to ask questions about things that have answers in the book but this forum is more hands on knowledgable than the books.
thanks for your help. Hopefully I'll fine time to do it today.
thank you,
Mark

 

[Uncle Phil]

Yeppers, #4 does not change so you balance the other three to match it.

 

[John OoSTerhuis]

Motion Pro has a tutorial YouTube video on how to set up and use their sync tool. Here's the link: http://www.youtube.com/watch?v=2nwP6R1P58A

Excellent video of the carb sync procedure, vacuum method. I recently did a comparo of this new MotionPro tool with the individual fluid reservoirs and blue fluid, and my old MotionPro mercury version, plus the SK flowmeter measuring intake airflow. Started with the flowmeter, then buttoned up the air cleaner and then used the blue fluid vacuum gage followed by my trusty merc sticks. While they all seen to work well enough with engine running smoothly, I found the SK settings off a bit from what the blue fluid tool needed to get balanced, and the merc sticks a very slight difference from that. I suspect that most folks won't notice the differences, nor care. But if I have a choice, I'll use the merc sticks. Disclaimer: I'm anal retentive on moST things ST1100 related. :grin:

BTW, I have a donated SK Flowmeter for loan. Comes with a 90 degree elbow attachment I fabricated so reading the meter can be done solo from the same side of the ST as the adjustment screw for that carb.

FWIW YMMV Yada

John

 

[Brant]

Your correct John, others on the XS11 site have had issues using MP 'new' set-up since EPA gave mercury related things the 'boot'. Problem seems to be some of the fluid hangs on sides of tubes and causes innaccurate readings. I have the MP 'stixs' with mercury prior to them being 'banned'. Sure wished I had one of the 'old school' mercury set-ups we used to use on diesel engines with the large tubes and such. Mercury 'stixs' still the best setup for ANY vacuum balancing of multi- intakes. Good results, and have been compared to mercury sticks for accuracy have been had with the same UK makers of the ColorTune(memory failing). Utilizing a stainless piston set-up makes it convenient to carry from place to place(nothing to spill), and is stored in its own soft case.

 

[John OoSTerhuis]

FYI - I contacted Rob Martin, the website owner, about the carb sync procedure error and he's graciously corrected the page (hit your refresh button if necessary):

http://www.st-1100.com/carburettor-balancing.html

John

 

[John OoSTerhuis]

I have no real complaints about the new MP carb sync tool. If folks follow the correct procedure in the video, AND LISTED right on the tool it should work fine and give good results. The separate fluid reservoirs require the additional calibration step over merc sticks. When I borrowed the new type MP tool someone had obviously not read the bright orange warning label in plain sight on the front of the tool and had hooked it up without backing out all the individual calibration screws first - sucked out most of the blue fluid. I bought the refill kit and set it up again properly and it worked just fine.

I can recommend it. The fluid is safe to use and clean up if spilled, just rinse with water, including skin. One thing I like about it is that with the vacuum lines removed and the little rubber tube caps installed and the reservoir screws closed, the tool can be safely and easily transported.

BTW, this tool can be used to "sync the throttle bodies" on ST1300s. I think that's the name of the procedure.

Edit: I made short adapters out of some brass tube stock I had to connect the MP sync tool to the ST1100's intake vacuum tubes. It comes with threaded 5mm tube adapters w/locknuts for those bikes that use them.

John

 

[sennister]

I have no real complaints about the new MP carb sync tool. If folks follow the correct procedure in the video, AND LISTED right on the tool it should work fine and give good results. The separate fluid reservoirs require the additional calibration step over merc sticks. When I borrowed the new type MP tool someone had obviously not read the bright orange warning label in plain sight on the front of the tool and had hooked it up without backing out all the individual calibration screws first - sucked out most of the blue fluid. I bought the refill kit and set it up again properly and it worked just fine.

I can recommend it. The fluid is safe to use and clean up if spilled, just rinse with water, including skin. One thing I like about it is that with the vacuum lines removed and the little rubber tube caps installed and the reservoir screws closed, the tool can be safely and easily transported.

BTW, this tool can be used to "sync the throttle bodies" on ST1300s. I think that's the name of the procedure.

Edit: I made short adapters out of some brass tube stock I had to connect the MP sync tool to the ST1100's intake vacuum tubes. It comes with threaded 5mm tube adapters w/locknuts for those bikes that use them.

John

+1 I have one that I have used a few times on the 1300. Haven't used it on the 1100 yet.

Sent from my Nexus 4 using Tapatalk 2

 

[maximark]

Couldn't get to it today. Had to go to the doctor with my wife. Hopefully Saturday will have time. Can't wait.