Yes it is. They seem like bs34 carbs. PO was known for never following factory or a manual for that matter ......so I would not be surprised if they are mix and matched bs34. Going to try a carb sync next.
-
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.
81 xs400 with 400 maxim carbs
- Thread starter dbou910
- Start date
Yes it is. They seem like bs34 carbs. PO was known for never following factory or a manual for that matter ......so I would not be surprised if they are mix and matched bs34. Going to try a carb sync next.
The bodies/bowls are from a dohc bike. The brackets/choke rod are from a sohc bike. What more than likely happened was the stock carbs where broken so they modified a set of dohc with sohc parts. I would up your jets to work with the exhaust you have.
I noticed that the pilot jet in one pic has the SOHC rubber plug installed. DOHC carbs don't use that plug. That, in and of itself, may be causing running issues.
That would make sense regarding the carbs. Just out of curiosity is that the stock exhaust for these bikes?
Ok so I removed the plugs and guess what it now idles without choke. But dies upon rev. Question..... while cleaning the carbs I could not remove the nozzle below the main jet. I pulled the diaphragm's and couldn't get it from that direction either. On my Vulcan 750 when the holes in the nozzle get clogged it will not rev same symptom's. Is there a trick to it if they have become stuck. Or does the dohc carbs have a traditional removable nozzle? I have a manual but it only covers sohc model. And BTW built a manometer so I can sync the carbs.
Thank You all for all the help
Thank You all for all the help
My guess would be that the pilot jets and passages are full of crud and corrosion. More and better cleaning!
Yes, the main nozzle that the main jets screw into is removeable. Remove the slides, remove the main jets, remove the main jet washers, reinstall the main jets most of the way and tap gently with a soft hammer to get the main nozzles to start moving. They are probably corroded in place. Be careful as there is a locating pin just a mm or 2 down and you don't want to shear it off. I did say to be gentle! Then remove the main jets and push the main nozzles into the throat of the carb.
You can download the Carburation manual, Chapter 4, from the Manuals sticky thread.
Yes, the main nozzle that the main jets screw into is removeable. Remove the slides, remove the main jets, remove the main jet washers, reinstall the main jets most of the way and tap gently with a soft hammer to get the main nozzles to start moving. They are probably corroded in place. Be careful as there is a locating pin just a mm or 2 down and you don't want to shear it off. I did say to be gentle! Then remove the main jets and push the main nozzles into the throat of the carb.
You can download the Carburation manual, Chapter 4, from the Manuals sticky thread.
Theres one eliment I like about those carbs,thats the fuel line built into the body .No banjo bolt and the funny little fitting that these carbs normaly have and are nortorius for breaking.
I know how the needle is mounted in the diaphragm is different. I will take a pic next time they are out. The nozzles were coated and clogged with debris. Thanks for the removal tip Dave. I really believe now that all passages should be cleared in these carbs but still getting the same result. Will idle no problems just will not rev. I know there is still plenty left on the check list to do but it appears that weather may slow progress a little this weekend.
Last edited:
My guess is that what ever nozzle and needle you have in there they are wrong for your bike. I would take them out so we can see witch ones you have.
Ok so I have pulled the needles and nozzles. Here are pics. I do also have the set that came from the parts box. Which should be installed???
Needles from the installed carbs are approx. 37mm from base of diaphragm. The parts needles are longer approx. 39mm from base of diaphragm
Thanks
Needles from the installed carbs are approx. 37mm from base of diaphragm. The parts needles are longer approx. 39mm from base of diaphragmThanks
Attachments
That was it!!!!! Still got a little tweeking to do but it seems like that was the primary issue. This is a fun bike!!! Very different feel from my Vulcan. Thanks so much for yours and everybody's help!!!
Glad you got it ,nowits time to enjoy
