One last time to save her

[Douglas Money]

I have pulled the carbs again and cleaned them again for the umpteenth time. The bike ran well when I pulled them the first time. The only problem being a slight stumble in mid range. (God I wish I had left them alone now!). I replaced the needles, seats and gaskets. I reset the float height and cleaned the carbs. The old needles were the steel ones and the new ones are vitons. I noticed that it required what I thought was a lot of adjustment to get the float height correct. I have them at 25 mm. I can get it to start on choke but can barely keep it running. I can get it to accellerate to high rpms but the low and mid range are very poor. It seems to like the choke on just to try and keep it running. It never liked choke in the past. Are the needles that different in length? I am getting desperate and the wife thinks I need to part it out now. Thanks for your help.

[TopCatGr58]

Hey Doug,

The viton ones are a different size IIRC in the thickness as well, and are not to be switched with the metal ones, they are only for the later 80-81 carbs with the different styled seats. You are probably not getting enough fuel into the bowls and that's why it's not running right. You should get the all metal ones, and put them in, reset the heights and such, and it should be right again.

T.C.

[Douglas Money]

I was told on here by pictures that the carbs I have are parts of different years. These are not the screw in seats, they push in and have the plate and screw that holds them in. I bought them in a kit.

[trbig]

It still sounds like the pilot circuit to me. It could be wrong parts, but the rpm range tells you where to look for the problem usually. At cold idle, problems are in the enrichener circuit and pilots. From idle to @ 3500-4000 rpm it's pilot circuit. Above that it's all mains... Good luck. Have you tried asking for some XS-Brotherly help from someone local? Some things can be learned in 5 minutes that would take a week or longer on your own. Just a suggestion.


Tod

[Douglas Money]

I am in the chicagoland area and would love to have someone show me whats wrong. I would cook them steak dinner. I can't get it to run for more than 1-2 seconds and that is pretty rough too. It feels like its got too low of a fuel level and can't draw fuel on its own.

Thanks.

[Douglas Money]

If I have to switch back to the metal needles, I assume I have to change the seats too. I purchased the kits from partsnmore and they are the 48-1408.

Thanks for any help.

[81xsproject]

TC and doug money, I have though about the steel vs. vitron needle issue a lot and have come to a conclusion that they should be interchangeable.

As long as the vitrons move freely up and down and the same floats are used it shouldn't make a difference. The float height may need to be adjusted, but the float heights are set by the position of the floats when the needles are seated so it should (should being the operative word) work. However, I can't test my theory on XS carbs because I don't have an older set. I hove done it on carbs from other bikes though.

[Douglas Money]

Just for giggles, I set the float 2.5 mm lower (more fuel in the bowl) and it improved. It sounds like it trying to run. I am going to try another 2. I think I might be on to something here.

[Douglas Money]

She runs. What a sweet sound. She has to be fine tuned, but she is starting and running on her own.

I believe it was the later carbs on an early bike needed the 23 mm setting. Seemed to be it. That and another cleaning.

Thanks everyone.

[trbig]

Seems to me I've even heard down to 21.5?? You'll know if it's too much when the floats won't raise up enough to stop the fuel. But yes... float levels are very critical.


Tod

[Douglas Money]

So, as long as the fuel isn't running over, the height isn't too high? Mine is able to be driven although it tops out at 5000 rpm. It starts loading up and won't keep revving. It misses during acceleration like maybe I have a coil going? Funny thing is, it starts right up now cold better than it used too. No choke, just hit the button and its running like you just shut it off. I still have to synch the carbs, no tool yet. It runs much smoother in the 4000 range than it ever did before.

[mitch]

Pick up wires

Doug you might want to check your pick up wires it could be your miss on accel.
Doug

[Douglas Money]

Yes, that was what I thought too, I was going to check them tomorrow.