Carb help please.

[Doc]

I have a problem with my 03 Xr100r. I got to use it at the race weekend and it was a dog.
It ran fine at idle but if you gave it more than half throttle it just bogs. So, I pulled the carb and cleaned a ton of gunk out, put it back together and now it runs for a bit and then dies. It won't idle. If I keep giving it throttle it keeps running but if I don't it dies.

Ideas?

Oh, and I have a 2 Bros pipe and uni pod. Needle is on the middle clip.

[smf]

other than the lack of idle does it run well through the rpm range? ...idle could be a simple mixture screw thing.

[SVRACER01]

sounds like an idle circuit. fill the float bowl with carb cleaner. or do a better job at cleaning it

[Doc]

Scott, I think it still has the bogging just a little higher up now (although I haven't tried to ride it, just reved it.

I'm Gonna try to clean it again

[TLRMan]

Get some really thin wire, and push thru those pilot jets, and air jets...
Pull a strand off of some 14 - 16 gage wire, to use as a poker outer....

[SVRACER01]

to use as a poker outer....

is that a technical term?

[TLRMan]

is that a technical term?

Christ, between you and Pete........

[dhuze]

......to use as a poker outer....

***WARNING*** don't put it near your eye.

[SSearchVT]

Is it backfiring at all? That's usually the idle circuit. Bogging can be bad gas, air leaks, or a plug on it's way out. Does it run better cold - or when it's warmed up? Check to see if the choke is opening and closing freely.

[beet]

Get some really thin wire, and push thru those pilot jets, and air jets...
Pull a strand off of some 14 - 16 gage wire, to use as a poker outer....

14-16 LOL big. A strand is all you need.

+1

[rebelpacket]

Guitar strings (the small metal ones) work really good for cleaning out jets. I've got some in my toolbox. Always good for a few strange looks.

With that exhaust, and air filter, did you change your jetting at all?

[Doc]

I searched down all the air leaks, I will check the plug, I did not change the jetting but do you think the stock needle would be adjustable? Maybe someone already did...?

[beet]

Guitar strings (the small metal ones) work really good for cleaning out jets. I've got some in my toolbox. Always good for a few strange looks.

With that exhaust, and air filter, did you change your jetting at all?

[Paul_E_D]

Are you sure it's jetting? I *think* this motor still has a points ignition. If the points are worn or burnt, you can jet til the cows come home and it will never run right...

[TheIglu]

No, his is CDI. Same engine as m '96 XR80. I converted my '88 to a '96 engine and went from points to CDI.

I have the same/similar problem. Thing runs wicked lean. I raised the needle a bit and it helped somewhat, but it never lasts for long before it sucks ma balls again. Open the throttle wide open and she dies. It does alright if you are slow to open her up, but she is obviously running lean. I'm running stock exhaust and stock intake but no airbox cover. I think getting that cover will be my first try.

I've opened and cleaned the carb numerous times. Also played with the idle mixture many times.

[Doc]

Running lean sounds right. I'll try raising the needle and reoiling the filter... Maybe even put the stock box back on.

[TheIglu]

I tried raising the needle already, not sure if that will do it for you.

I wonder if there is an XR100 forum somewhere.....go to it Doc! Let me know!

[oreo_n2]

does it run right if half choked? My 50's are like that til the summer heat gets here... if it works... just keep the choke on.

[number9]

Can I hijack this thread, please? Awesome.

I put the requisite amount of Sta-bil in my 900SS before the winter, and ran it for at least 15 minutes to get the gas circulated through the lines. But it looks like something fucking froze anyway.

It's been mentioned to me that I should pull the float bowl and clean it out, as that's where the gas/water mix usually gooifies. Can I pull the bowl without pulling the whole carb off? I know my way around EFI, but not carbs...

[Doc]

Nope.

[number9]

Thanks Doc. Once I pull them off to get to the bowls, do I have to worry about fucking up the jetting? Do I need to touch that stuff to get to the bowls?

[Paul_E_D]

your jets need to come out for a "flossing". That is where the buildup causes problems.

[number9]

Paul: Okay... but are the difficult to insert/remove? When I hear of jetting bikes (as in tuning them), is it just the selection of jets/needles that is important, or is where they're placed in the carb (think TPS synchronization in EFI world) important too?

Am I in over my head on this one, or is it really not that hard to do?

[rebelpacket]

Its really not hard to do. Your carb has the same jets in each carb (at least it should be, and if it isn't you've got bigger problems, Your running the Mikuni CV's that came with your SS, right?) To get the carbs off the 900SS, you've gotta pull off the airbox (that includes, battery coils, etc). From there, just pull them off the bike, and drop the covers on the bowls after draining fuel out, and unscrew + clean each jet one at a time. Check the choke plungers too, they seem to have a funny way of getting nasty quick.

[number9]

AFAIK the jets in each are the same; I had the bike tuned last year at Moto Milano up here in Windham. I thought standard carbs were Dell'ortos? But I could be wrong. What you've described doesn't sound so bad, I might give it a shot over the weekend...