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KLR 250 Carbi problems

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Hi I have recently bought a 1988 klr 250, I have pulled the carbi apart twice and cleaned the main jet which was clogged, however i must have done something because the bike runs well till give it full throttle then it chugs and splutters. The bike ran ok before so I dont think it could be a gasket or valve problem, doesn't blow smoke, idles high and doesn't drop in revs quick enough. Any clues?? Also to the back of where the choke cable enters carbi there is a black plastic inlet/outlet that looks like it should have a hose attached(its the same as fuel inlet) but its missing and there doesn't seem to be any where for a hose to go had there been one... I tried blocking it but bike didn't run at all. HELP!!!

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Why'd you take it apart to begin with?

I'd buy a new main jet to make sure. The one you have could have been bent by the cleaning. It is 21 years old. Typically a stutter indicates too rich of condition which could happen if you've enlarged the diameter of the jet.

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Hi thanks for replying, I first pulled it apart as it was running ok but seemed to be starving, it was gutless and it wouldnt idel at all(do you know what that means? since i pulled the carbi apart again it does idel however when I give it a little rev it takes ages to get back to around 1,000rpm-sometime sits on 3 & 1/2 for a while then eventually goes back to 1,000)

I put a washer around the needle, now it runs great till 5,000 rpm chugs til 8,000 and runs great again, I had it up 130kph today and couldn't believe it!! Is there any other ways to fix my mid range?

Thanks for the tip about the jet I'll see if I can get one soon, you see I live a long way from a town so I don't get a chance to get in much.

Thanks for your time :)

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Thanx mate it runs heaps better!! It does have a little chug in the middle when it gets warm, any clues as why that is? It backfires now really loudly too, I don't really mind it too much but it might give some one a heart attack if it goes of next to them. Which model do you have?

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Oh one more Q.. how do I know when I've turned the screw out too much, other than when it comes right out?

Thanks once again for your help

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Thanx mate it runs heaps better!! It does have a little chug in the middle when it gets warm, any clues as why that is? It backfires now really loudly too, I don't really mind it too much but it might give some one a heart attack if it goes of next to them. Which model do you have?

When you say chug, do you mean hesitation (too rich) or bog aka no power (too lean)? Mine's a 2005 KLR250, the last year of its production.

Oh one more Q.. how do I know when I've turned the screw out too much, other than when it comes right out?

Thanks once again for your help

To master thy fuel screw read this:

http://www.thumpertalk.com/forum/showthread.php?t=327405

You may need to adjust your pilot jet as a result.

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Thanks I'm learning heaps!! I think it is a chug so I'll try backing the screw off, by the looks of it I need a bigger pilot jet but I could be lucky. I'll give it a try . There is a TK power pipe on the bike from a 94 model do you know anything about these.. IE would it improve the performance much and is a definite that once a new pipe is added there has to be a jet change?

Thanks its running better all the time!!

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Typically an aftermarket can will almost always make it run even leaner. I know nothing about that pipe though. Can you put the stocker back on and do comparisons? It should be easier to jet with the stocker. Once you've got it dialed then put the TK one back on and jet again. :)

More background for any carburetor:

http://www.thumpertalk.com/forum/showthread.php?t=404426

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Unfortunately the previous owner changed it so I cant compare them, I have found that it has real trouble going along at moderate speed it likes going slow or really hard but when on a flat at about 6,000rpm it kinda surges and as soon as you want to power up for a hill it just wont go over 85k's.. It's really strange it goes great sometimes until you hit 6th and then just chugalugs til you have to drop it back to 5th. I was thinking of drilling the pilot jet to make it a bit bigger whataya recon?

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Well, I just realized that you are the evil sheriff of Hazard County :banghead:

However, sixth gear is totally an overdrive. The motor just doesn't have the oomph to give you actual acceleration in that gear due to the gear ratio. If it surges at 6K rpm, you're lean on the needle and a portion of the main jet. I'd richen those two circuits. Lower the clip position by one and get the next size up main jet to see if it improves. :)

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He he yeah I gotta get the bike runnin well so I can catch them duke boys!! :banghead:

Thanks mate I'll give her try in the morning, oh and thanks for the link to that carbi page it was brilliant!

Soon this little KLR is going to be running like a dream!:)

I'll let you know how she goes :banghead:

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Hi there, I think I've finally worked out the difference between a chug and a bog, I tried to richen the main jet and it kept on hesitating thru the mid range, so I found a tiny nut (about 3mil) in my bits drawers that had a really small hole in it, drilled the end of the mainjet where the fuel enters and tapped it in nice and snug.. Started it up and it runs like dream!! thanks heaps for all the help I think I understand carbi's heaps more.. still more to learn of course but for this KLR the problems are sorted. :thumbsup:

Have fun on your beast!! :excuseme:

Got any tips on how to install a police horn on a motor bike? :confused: .. Just kidding

Thanks once again :banana:

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Hi there, I think I've finally worked out the difference between a chug and a bog, I tried to richen the main jet and it kept on hesitating thru the mid range, so I found a tiny nut (about 3mil) in my bits drawers that had a really small hole in it, drilled the end of the mainjet where the fuel enters and tapped it in nice and snug.. Started it up and it runs like dream!! thanks heaps for all the help I think I understand carbi's heaps more.. still more to learn of course but for this KLR the problems are sorted. :thumbsup:

Have fun on your beast!! :excuseme:

Got any tips on how to install a police horn on a motor bike? :confused: .. Just kidding

Thanks once again :banana:

http://www.klr650.net/forums/showthread.php?t=61886&highlight=horn

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 I fought couple days here with this problem anyway we solved it and it was not the pilot jet or the main jet it was that for whatever reason when I re and re'd the carb the vacuum slide was binding(do not know why) and freeing that up I got my bike back..maybe the slide has been binding some all along. Maybe I crunched the spring. Thought I would mention it case somebody else runs into the same problem

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