HELP.........
Well I finaly got together with a friend from the V4BBS to do the carb sync yesterday. The bike was running fine but my milage was a little low so I thought I just needed to sync the carbs.
We were using the Motion-Pro stix. Well when we started cyls 1 & 4 were close and 2 was way low and fluttering and 3 was a little low. We started adjusting and couldnt bring up 2. At one point we were so out of wack that the idle adjust was haveing no effect, we started wondering just what we had done to it at that point. Did some more turning and got it back to the correct idle but now cyl 2 & 3 are dead even but very low, 10-12 lines compaired to 1 and 4 is just 2-3 lines low.
We gave up at that point thinking that I now need to pull the rack and rebench sync, doing a rebuild while they are out. I took it out for a little ride and found that it now has a little bit of a vibration and puttering sound at idle and after you rev it up in neutral it doesn't drop back to idle as fast as it did.
I picked up a bottle of Techron this afternoon and will run it through this tank when I fill up for the week. I hope this helps. This is my main mode of tranportation back and forth to work right now and I don't want to pull the rack. My friend does have a rack off a Sabre he offered me to be able to rebuild and just swap out so the bike isn't down long. I just don't want to have to pull them at all if I can avoid it.
Anyone have any ideas?
First off lets go with the sync if you did not tear the carbs aparts to seperate units you really have no need to sync.A simple bench sync will do just fine when you have them out.Second the Num 1 carb is the base carb it is the one you base your other readings off I would get your friends rack and put it on. I would take a look at your plugs even if they are fairly new one might be fouled since you were playing around with the sync settings the one might have got way rich and maybe just maybe did it in....
I would like to reverberate what Allen said about sync'ing not really being needed unless the carbs have been apart or some major work being done to the heads and such.
When you sync carbs you are just mechanically making the butterfly's open virtually the same. You do not adjust the air/fuel mixture at all doing this.
The idle drop or pilot screw adjustment changes the fuel/air mixture and it is easily tackled. Basically get the bike nice and warm turn your idle up to maintain say 1200 RPM. You lean or riched the pilot screw and listen very carefully or if you have an extremely quality tach that shows very small incremental changes. You want to lean it too the point that it peaks out RPM's and starts to fall off, back up just too the rich side of the fall off point.
This adjustment usually makes a good change unless it was already spot on.
The previous owner had the carbs done by the steeler and were bench synced but not once they were back on the bike. I just wanted to try to get it tuned and running the best I can. I have talked to a few people and have a method to try to get it back to where it was without pulling the rack. Unfortunatly I wont be able to swap out the rack with the Sabre as the airbox is different.
I will update as progress is made if any.
Kerry I have bench sync'ed many and they are always so close it would NOT be worth the effort in putting gauges on and trying to get them better.
I would pay MUCH more attention to the idle drop (Pilot screw) adjustment as it is can make the bike run much differently if off either way by much.
Obviously we have not discussed jet/shims in anyway so I assume they are all stock as well as exhaust. As too rich or too lean on this setup will NEVER be adjusted by sync'ing or idle drop adjustment.
We are going to try to get it back where it was before on Wendsday. All I want at this point is to get back to the starting point. It was running fine before I started messing with it. I havent touched the idle drop or the pilots. It is the stock exhaust and I would suspect the stock jetting. I don't think any of that was changed.