Bike idles great but dies as soon as I let out the clutch.

Bike idles great but dies as soon as I let out the clutch. I have to get the RPMs high in order to get the bike to move with out dieing. If the RPMs are above 4K the bike runs great. If the bike is idling, the bike runs great. At lower RPMs it just dies but if the RPMs are alittle higher like 3K then it acts as if it is losing its spark and the catching it again. So it is like you are riding down the rode turning on and off the run switch.

Any ideas?

Thanks

 

could it be a dirty jet in the carb for that rpm (pilot,main)? does it smooth out when you at higher speeds? maybe dirty contacts on the coil?

 

Sounds like the Pilot Jet Passages and the Pilot Jets themselves are clogged and not passing any fuel into the engine at lower than Main Jet assisted rpm's.

Just what EXACTLY does it do with the throttles closed?
Die?
Chug?
Try to fire but stumbles and can't catch-on.

All these symptoms are related to Pilot Jet Na Mixtures being clogged or closed-off not feeding fuel to the engine for Idle at all.

 

Re: Bike idles great but dies as soon as I let out the clutc

when I close the throttle it starts to die. I open the throttle to catch it but it just continues to die. I have to turn on the choke to get it to catch. I have taken these carbs apart so manyt times. I thought I have cleaned out everything. I am not sure it there is anything that I missed. I have slip on mufflers and I took them off the other day. When I look through them the is no baffel at all. I can see right throught them. Is it possible that I may need to re jet?

Thanks
for all your help.

 

Re: Bike idles great but dies as soon as I let out the clutc

im not running any pipes and i didnt have to rejet, I have my carb very clean right now. Did you clean out the emulsion tubes really good. and did you clean the little holes in them? are your floats set at the right height? Is this a new bike to you or have you had it for awhile?

 

Re: Bike idles great but dies as soon as I let out the clutc

It is a new bike to me. I did celan the emulsion tube really good. I also checked the floot levels. They were okay. By accident I put a main jet into the pilot jet area and the bike ran better. It was fluiding alittle but ran pretty good.

I have posted a message in the buy and sell area for some used pilot jet to play with.

 

Re: Bike idles great but dies as soon as I let out the clutc

did you put your air jets back in right?

 

Re: Bike idles great but dies as soon as I let out the clutc

Yeah. I put them all back in right. When I switched the mains and the pilots the bike ran great until half throttle and the just bogged down like it was staring for gas.

Hey... Of topic a little. Do you have pics of the "In process Bobber" I have a xs 650 that I want to chop.

 

The key is you have to give it Enrichment to keep it going.
That means your Pilot Mixture Screws aren't in the game yet.

Give those Pilot Mixture Screws some Richness.
Come OUT to 3 Turns out and see if she'll run like that.
If it don't ... test for Fuel Starvation.

Use starting fluid or Propane Gas from an un-lighted Propane Torch right in the Airbox Inlet.
If it pops and goes with the external source of Fuel ... you got no Pilot Fuel happening.

Once you get it running on Pilot Jets ... Tweak the Screws for Plug coloration.
Try to set the Pilot Screws sothat you are getting a Tan to Brown Plug Read.

What do those Plugs look like right now?
Pull the Plugs and take a picture of the business ends and lets see them.
We'll do more after we see what's going on with the Mixtures.

 

Re: Bike idles great but dies as soon as I let out the clutc

http://www.xjbikes.com/Forums/viewtopic/t=9137.html
i still have to put up some pics

 

Re: Bike idles great but dies as soon as I let out the clutc

The bobber looks great.

Thanks Rick for the direction. I have to work late tomorrow night but I will get right on it on Thursday. When I cleaned the carbs and put them back in I turn the screws out 2.5 turns. Do you think being off 1/2 turn would case problems. Also, I just put in new plugs. How long do I need to run the bike to be able to see the color or a color change your talking about.

Thanks again.

 

Re: Bike idles great but dies as soon as I let out the clutc

Ok. I set the pilot screws to 3 turns out and still the same. i ended up backing them out to 5 turns and ruins better but still not perfect. The bike is ridable now though. I am thing the it is sucking air somewhere. maybe the carb boots ( I guessd thats what they are called ). What is the best way to check for vacuum leaks. Can I use starter fluid to check for leaks. Using propane scares me a little because you can't see it and don't really know how much of iot is around. Don't want to go boom.

thanks

 

I think you need to open up the pilot jets one size.
Mine did exactly the same thing. I opened up the pilot jets and it's like a new bike. Also sync the carbs as it can make all the difference in the world.

 

Somebody gave me a set of jets 112 mains and 43 pilots. What I have in there now are 110 mains and 40 pilots. Do you think that these are a little too big?

 

Re: Bike idles great but dies as soon as I let out the clutc

You can use starter fluid to check for air leaks just a little messier.

110 and 40 are stock on my Seca 650.
Chacal had a post were you could get an idea of how big to go with jets for modifications.
112 was the size for just after market 4into1 header exhaust.