I didn't plan to replace the needles, but I had no idea they were different. Thanks for the heads up. I will probably also replace the float needles and the seat; they look like they could use it too. Will the carb boots on mikes fit or should I just get them from an xs400 specific site like partsnmore? I am considering replacing them as well. I repaired mine, but for the sake of reliability...
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Chris, I have a theory with regard to how I can be both too rich and too lean at the same time. If the float needle and seat are not sealing properly I might be leaking extra fuel. The extra fuel could be enough to make idling rich, but would not be significant enough to keep up with the demands of higher rpms. Oh, this is interesting to think about 
It now makes sense that I'd need to lean up idle so much despite my free-flowing mufflers. As soon as I am on the throttle I hit a wall at like 3,000 rpms.
It now makes sense that I'd need to lean up idle so much despite my free-flowing mufflers. As soon as I am on the throttle I hit a wall at like 3,000 rpms.On order:
Universal Fuel Petcock Adaptor Plate (46mm eye to eye and I measured 17 times, so this better be right!)
Intake Carb Holder Set
Float Needle & Seat
Universal Fuel Petcock
Main jets
Pilot jets
Vacume tubing
Fuel tubing
Fuel filter
Fork boots
In the garage:
Tires
Rim strips
Tire tubes
Valve stem seals
Fork seals
Mirrors
Turn signals and tail light
Painted front/rear fenders
Fiberglassing materials for a seat cowl/pan
Seat foam
Tapered steering bearings
This morning I am boiling my carb bodies in vinegar and lemon juice!
Universal Fuel Petcock Adaptor Plate (46mm eye to eye and I measured 17 times, so this better be right!)
Intake Carb Holder Set
Float Needle & Seat
Universal Fuel Petcock
Main jets
Pilot jets
Vacume tubing
Fuel tubing
Fuel filter
Fork boots
In the garage:
Tires
Rim strips
Tire tubes
Valve stem seals
Fork seals
Mirrors
Turn signals and tail light
Painted front/rear fenders
Fiberglassing materials for a seat cowl/pan
Seat foam
Tapered steering bearings
This morning I am boiling my carb bodies in vinegar and lemon juice!
TheMainMuel
Cycle Junkie
Lookin good bro!
When I boiled my carbs I didn't have enough vinegar, so I also added some lemon juice which I would not recommend using; cleaning went well, but something in my mixture recrystallized on my carbs. I am boiling them again in straight water to clear the junk off.
ahale2772
XS400 Addict
bc, its weird that you have a 170 air jet, my main jet was a 170 i wonder if it was just swapped...
ahale2772
XS400 Addict
interesting...so should the mains and air jest be interchangable?
I officially hate the haynes manual; all the figures are wrong... Are you serious Chris? 170 is correct?? I ravaged the internet for information on this and every quote I found (dozens) were wrong. All of them say the pilot air jet is a 30.
Ahale; I don't think you can interchange them because the main jet is a large round type and the pilot air jet is a small round type.
Ahale; I don't think you can interchange them because the main jet is a large round type and the pilot air jet is a small round type.
The #30 jet is the starter jet not the pilot air jet that is on the other side of the carb. I don't know why the pilot air jet size is not listed? But after 12 years of working on 400's carbs it is stock. I don't think they even make a #30 jet.
The Haynes manual shows a photo of the pilot air jet being removed from the face of the carb and the caption under the pictures says "removing the starter jet." I wonder if its just a blatant error. There is a #30 jet; bikebandit has them and I ordered them on accident...
Thank you for confirming. My inexperience got the best of me, but fortunately the parts are cheap. The haynes covers too many years for sizing to be accurate, never mind the fact that there are obviously a few mistakes in the book.
new kid on the brat
new kid on the brat
wow bcware..... you are persistant!! i hate stuff that has been raped and abused ran hard and put away wet! although it does tend to teach you more in the long run.... i tend to lose my patience and walk away..repeatedly!! i comend your patience!! keep up the good work!!
The parts have started coming in already; the first thing I noticed was that the replacement float seat from partsnmore for my 78 does not fit; it is way too small. I just double-checked and I definitely bought the right one as well and it is labeled as 77-79 specific.
