Jump to content
Sign in to follow this  

xr400 dies when I turn choke down to half?

Recommended Posts

Just pulled my carb, cleaned it, put in new jets, 155/58...

Starts right up in full choke, idles very fast... turn it down to half choke and it dies immediately. Any ideas?

Share this post


Link to post
Share on other sites

pilot jet is plugged - just cause its new doesnt mean its not plugged!!

missing air/fuel screw and or Oring for it.

Share this post


Link to post
Share on other sites

Is the float moving freely?

Is there an air leak between the inlet manifold & the cylinder head?

Share this post


Link to post
Share on other sites

Intake, motor, exhaust are they stock? What's your elevation? Your jetting could be lean. What jets were in there before? Why did you put in new jets? Was your bike running better before you replaced them?

Share this post


Link to post
Share on other sites

Bike wasn't running good at all.

Stock Engine, Exhaust...

Uni Air filter

Three 1/4" holes drilled in the baffle, looking into grinding header welds.

Yes I pulled the jets but the only markings I found on them was 138 on the main? and 52s on the pilot. Neither of which can be right...

Share this post


Link to post
Share on other sites

52/142 is stock from what I see on the fische. Why did you change them so radically?

Share this post


Link to post
Share on other sites
52/142 is stock from what I see on the fische. Why did you change them so radically?

What is the fische? Is that really stock?

Share this post


Link to post
Share on other sites
What is the fische? Is that really stock?

It is a parts schematic. Yes, that is the factory jetting. The factory jets them lean like that to help pass emissions. It's up to us to jet them right after we get them.

Share this post


Link to post
Share on other sites
It is a parts schematic. Yes, that is the factory jetting. The factory jets them lean like that to help pass emissions. It's up to us to jet them right after we get them.

Well if that's the stock for 2001, then I must be too rich, I jetted like that because so many other people seem to have it that rich

Share this post


Link to post
Share on other sites

How soon after getting it started with full choke are you moving it to half choke? It's supposed to have a high idle on full choke. Let it run on full choke, won't hurt it. When the engine starts to slow or run rough on full choke, that's lets you know it's time to move it to half choke or completely off.

Share this post


Link to post
Share on other sites
How soon after getting it started with full choke are you moving it to half choke? It's supposed to have a high idle on full choke. Let it run on full choke, won't hurt it. When the engine starts to slow or run rough on full choke, that's lets you know it's time to move it to half choke or completely off.

One time for like, 2 minutes.

It immediately dies, if everything was working right it would at least try to run.

Seems to be running perfect with full choke though, no bogging whatsoever.

Share this post


Link to post
Share on other sites
One time for like, 2 minutes.

It immediately dies, if everything was working right it would at least try to run.

Seems to be running perfect with full choke though, no bogging whatsoever.

Which leads me to believe it isn't getting enough fuel? because choke richens the mixture.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×