Carb Syncing was easy!

[don07tncav]

Just like you gents said in the Tech tips,. The directioons were easy to follow and it took longer to take the seat on and off than to sync the carbs. Thanks again for such an excellent site!

[nashville_bill]

Don,

I knew you wouldn't have any problem syncing them. Now, does it run better than your XS650?

[don07tncav]

Yes Bill. Even with the faring and saddlebags the XS11 is a superior bike. The acceleration with all 4 cylenders is better and I like the overall ride. My 650 seemed to struggle at times heading up hill with this fat boy on it but the SX11 doesn't seem to be phased at all. With the carbs syncd it doesn't lag at all starting out. I took it out for a real test ride last night, between the carb cleaning plus syncing the XS11 seems like a totally different bike. Now I'll track milage, I was getting between 32-34 MPG before doing the deeds, I'm curious to see what happens now.

[Brasco18]

How did you sync your carbs? carbtune? bread tie? vacuum? I did the vacuum method last night. I think it is pretty good, although now I want to put a carbtune on it to really dial it in. I wonder if the dealer in town would have one...

[stereomind]

heh.. I THOUGHT it would be easy to sync the XJ last night.

sooo.. I hook up the gauges, to find out that the readings are all over the place... Maybe because we just replaced a bunch of valve shims.. Started tweaking the mixtures, and all of a sudden the bike would not come down to idle.. with the idle screw all the way out, not even touching the throttle arm. The closer I got to even readings, the more it raced. Go figure...

then, I pushed the linkage between 3 and 4 down with a screw driver, and it stalled out.. which means that butterflies are not closing by themselves.

Off go the carbs (thankfully they come off rather quick on the XJ).. Found a bunch of crap under the butterfiles... Looked like grains of sand, but not as hard. Cleaned them out. Carbs go back on... Ah S#!%!!! #2 is dumping gas all over the place. Tapping the bowls did not help.

Off with the carbs again... Took the float off #2, to find a piece of plastic lodged inside the valve.. Must've broke loose from somewhere during the first de-carbing.

Short story long... Ended up bench-syncing using 4 strips of cut up business card, stuck the carbs back on... Got VERY close on vacuum readings just on bench sync! (I was so proud).. Anyhow, 3 passes of colortune later and some fine tweaking on the sync screws, and we've added about 15 hp to the bike, or so it seems. It pulls like a freight train.

all is well that ends well, I guess.

[Ken Talbot]

And you used a YICS tool so you got true vacuum readings for each cylinder?

[Brasco18]

I only had it out once since syncing, but it seemed pretty rough between 1k and 4k. Is that typical? I noticed a lot of threads on rpms under 4k. I know these bikes are super quick off the line, and they tend to be pretty cold blooded, but is there a simple way to take care of the roughness at lower rpms? Is there a jet mod possibly? Would bad float levels do it? If it could be the floats, how do I check them using the clear tube method? The carbs have always been a trouble area for me on my other bike too.

[stereomind]

I did a pass with and without the tool to compare the readings. Honestly, I think that if you have 4 vacuum gauges, YICS tool is not as crucial. I can't tell the difference on the 750 or the 550 whether I use it or not. It takes a little bit longer without it, since adjusting one carb throws the others off a bit.


Brasco, I think a colortune after syncing helps with the roughness... When you play with sync and idle adjustments, idle mixture tends to change. As the butterflies close, idle mixture goes rich.