OleDoc
FREEBIRDS MC Central NY
Am I the only one that has not had to clean there carbs a million times?Pull apart, a little carb cleaner and 125lbs of compressed air, done.
the third time i did mine i did the compressed air trick
-
Enjoy XS400.com? Consider making a donation to help support the site.
XS400.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
Runs on only one cylinder
- Thread starter jscgdunn
- Start date
-
- Tags
- running problems
the third time i did mine i did the compressed air trick
Carb balance - my DOHC ran really poorly when I had bench synched it. Much better after I did the DIY carb balancer trick with tubing and ATF fluid.
The problem I believe is the YICS - each cylinder gets different airflow. On mine, the jets are even different sizes (by 4 sizes!) to compensate.
It sounds like you're getting there, but I would recommend a fluid carb synch, and of course, recheck that your valve shims are adjusted properly (can't remember if you already did that or not.)
The problem I believe is the YICS - each cylinder gets different airflow. On mine, the jets are even different sizes (by 4 sizes!) to compensate.
It sounds like you're getting there, but I would recommend a fluid carb synch, and of course, recheck that your valve shims are adjusted properly (can't remember if you already did that or not.)
DIY Carb Synch example: http://www.powerchutes.com/manometer.asp
DIY Valve Shim zip tie instructions: http://kzrider.com/forum/21-tools/320714-the-cheapest-valve-shim-removal-tool
Some people pooh pooh the zip tie method. I loved it. No problems afterwards.
DIY Valve Shim zip tie instructions: http://kzrider.com/forum/21-tools/320714-the-cheapest-valve-shim-removal-tool
Some people pooh pooh the zip tie method. I loved it. No problems afterwards.
jscgdunn
XS400 Enthusiast
Good job drop over sometime; love to see your magic!
jscgdunn
XS400 Enthusiast
Thanks...I agree the valves need looking at as well. thanks!
thanks alot jscgdunn,
i have them apart right now, looks like one of my needle and seats isnt working right (doesnt move freely)
also i have a mixture screw that is totally destroyed.
i am making a trip to the shop after work to order parts. ill keep you updated on my success (wishful thinking) lol
i have them apart right now, looks like one of my needle and seats isnt working right (doesnt move freely)
also i have a mixture screw that is totally destroyed.
i am making a trip to the shop after work to order parts. ill keep you updated on my success (wishful thinking) lol
You're lucky you have a shop that has the parts you need. I had to order all of mine from MikesXS.com (who, by the way, were excellent.)
jscgdunn
XS400 Enthusiast
Hi,
My name is Jeff, and I am addicted to carburetors, and I am willing to go through the twelve step process (sorry that’s my other group).
Yes, I had mine apart last night and boiled the bodies in vinegar and was (that smells awful) threatened with same treatment from “she who cannot be trifled with”. The needle and seat valve needs to work and are a pretty cheap replacement. I really believe my starting problem is related to the enrichener (ie “choke” or priming) circuit. In one of Replies above there is a link that goes into pretty good detail on it. My left float bowl is suspect as I cannot blow carb cleaner through the float bowl passage. Next step is to apply heat.
Really this make perfect sense; as the enrichener circuit draws fuel from the bottom of the float bowl it stands to reason that a lot of the gunk would get drawn into here as well. Once the check ball is stuck the circuit cannot work effectively. Be interested in thoughts on my theory here.
Good luck!
OleDoc
FREEBIRDS MC Central NY
OleDoc
FREEBIRDS MC Central NY
I'm trying the 6 pack process, but I'm not working out!
jscgdunn
XS400 Enthusiast
Put carbs back together on Friday a night and today got them out to the shop. Really worked on the enrichener circuit and was all clear except for one float bowl. Today applied heat to the float bowl with propane torch. This seemed to do the trick as I was then able to spray carb cleaner through hole at bottom of bowl and up through the top. Bolted the carbs on and she fired up! Runs fine on both cylinders. Still need to sync carbs and check valves.
Thanks again to everyone!
OleDoc
FREEBIRDS MC Central NY
i find i get more done on the 6 pack process then i do on the 12 pack process
jscgdunn
XS400 Enthusiast
Back again everyone,
So the bike now starts and runs well. Took it to shop and valve clearances were checked (good), and carbs synced.
Will rev to redline in neutral.
Finally the snow disappeared, and we got ride it. Pulls pretty good til @5000 RPM then acts like it has a govenor on it. Just will not rev under load. Seems like starving for fuel.
It does have a clear in-line filter and clear gas line. The line always has a large amount of air in it. Is this normal?
My thoughts:
New OEM gas cap: does not vent well enough?
Air in Gas line?
Has brand new OEM fuel petcock so should not be issue? Tank is a bit cruddy inside; could be petcock screen is plugged?
Thanks again,
Jeff
lowpunk
XS400 Member
Maybe i missed it but what is your filter/exhaust setup. Sounds like a jetting issue but i'm not sure if i know enough to say. Whats the filter, exhaust and current jetting?
jscgdunn
XS400 Enthusiast
jmd_forest
Bldg 1980 XS400 Cafe Bike
Have you set up the ignition timing?
jscgdunn
XS400 Enthusiast
Thanks again to everyone for the help. Tried a bunch of things and then pulled the cards again. Turns out the mechnainc (was that me?) did not tighten the main jet on the left carb. It was loose and rolling around in the float bowl. Buttoned it all back up. Runs great and my son took off to Vernon BC (560K) and it ran great all the way. Oh to be 22 again.
Jeff
