Low idle at start:

[richardthemotorcycle1]

Hey guys, trying to finish my 1981 XS650, carb was doing good but now when you start bike low idle and no throttle, took off air boxes and notice when giving it throttle my carb slides are just shaking when using throstle but not going up, what's going on?

 

[TwoManyXS1Bs]

Hey, Richard! Have you done the diaphram/slide test? The one where you cover the diaphram vent and see how the slides drop?

 

[richardthemotorcycle1]

Hi Steve, no I didn't do that yet, carbs are on bike, Thanks will test them and see, might have to replace those diaphragms.

 

[richardthemotorcycle1]

Hey guys did the diaphragm slide test, both came down slow, left side moved slow, took longer for it to drop.

 

[retiredgentleman]

When a bike won't respond to throttle, the first thing to check is the pilot circuit.

Pilot jet/mixture screw/passage ways, etc.

Does your fuel tank have rust in it? Do you use fuel filters?

 

[richardthemotorcycle1]

Tank has some rust but not bad and no filter, should I use a filter? did clean these about 4 months ago, its been sitting waiting for mufflers.

 

[retiredgentleman]

Tank has some rust but not bad and no filter, should I use a filter?

Yes, you should use fuel filters. The rust has likely made its way into the pilot jets. Remove the carbs to the bench, turn the carbs upside down, and remove the float bowls. Remove both pilot jets and clean the dirt/rust from the jets.

 

[richardthemotorcycle1]

Thanks retiredgentleman will do, and I will get a gas filter too

 

[richardthemotorcycle1]

Yeah it's dirty

 

[retiredgentleman]

Yeah it's dirty

I don't recognize that picture? What part of the carb is that?

 

[weekendrider]

I believe you are looking down through the top, with the diaphragm/slide/needle removed, at the needle jet?

 

[retiredgentleman]

Yes, maybe that is the needle jet..................thanks for that WER.

Dirt is dirt, but I recommended he take out the pilot jet, not the needle jet.

 

[richardthemotorcycle1]

Yes your right weekendrider, I took it all apart to make sure everything is clean, in the process of painting my gas tank I must of got some premier dust in there.

 

[richardthemotorcycle1]

Got it all out.

 

[weekendrider]

WAY to organized there Richard. If you want to be challenged dump those carb parts in with the brake parts container and shake it up.
Get a six pack of energy drinks and you got all night to finger it out.

 

[richardthemotorcycle1]

Lol, yeah I like to be organized, retiredgentleman, yes I took out pilot jets too, When you speak I listen thanks.

 

[richardthemotorcycle1]

Here are my mix screws, my question is, after clean up can youvput them in this way. I know probably a dumb question, I think the last time I had to fish out the o rings.

 

[richardthemotorcycle1]

I was watching a video on the forum about bs34 carbs, this guy was using silicone spray on the diaphragm, is that ok to use? I've had my carbs a parts for about three or four day, will my diaphragm be ok to put back together or do I need to give them a spray? I have those parts covered.

 

[retiredgentleman]

I was watching a video on the forum about bs34 carbs, this guy was using silicone spray on the diaphragm, is that ok to use? I've had my carbs a parts for about three or four day, will my diaphragm be ok to put back together or do I need to give them a spray? I have those parts covered.

I have never used silicone spray, but silicone is a good thing to put on rubber. Keeps the rubber from drying out and cracking. I use a little dielectric grease on my diaphrams, which is silicone.

 

[richardthemotorcycle1]

I will use a little dielectric grease on mine too, thanks so much.