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Xr600 top end power

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Does anyone have a problem with their carbie where it gets bogged down in?

4th and 5th. Even when i accelerate smoothly it still seems to bog down

i need some help please before i could get to 130km/h no trouble but now after 100km/h it kind of goes blu blu room blu blu

Need help

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I changed the carby because it would not idle with the old one the bike is a 1996 model and i put on a 1999 model carby

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the new carby has 130 65 jets

well there you go!

You have a restricted stock Im assuming australian market carb..

your pilot is a ok bt your main is way lean unless you have the needle pulled up all the way, but even then you need a 152-155 main jet if your close to stock or stock, needle in 3rd clip

the reason why you cant pull more on the topend is because you cant pull anymore gas through that teeny hole

de restrict the bike(snorkel, air filter at the least) then upjet on the main

good luck!

christian

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Take that 130 main jet and throw it as far as you can...or keep it and drill the orifice out to a proper size. I don't know what has been done to your bike so I can only guess that it will need something around 160-165. Change it right now before the engine suffers a meltdown. I'm serious.

Also, your old carb did not likely need to be replaced, but simply cleaned if the ACV wasn't ruptured. I have not experienced a ruptured ACV yet, but others have indicated that it causes idle mixture problems.

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its amazing to me how the bike even runs...goes to show it takes a lot to go to extremes on these bikes...

I mean imagine a 45 pilot jet or something? jajajaja

"fart through a whistle? try on tight slim jeans youll know then!

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Also, your old carb did not likely need to be replaced, but simply cleaned if the ACV wasn't ruptured. I have not experienced a ruptured ACV yet, but others have indicated that it causes idle mixture problems.

hey HT...

I tried drilling jets once...wasnt a perfect art but I used acetylene torch cleaners(welding) and used them to ream pilot jets...worked ok I guess...

and I also experienced the acv valve issue...mine was ruptured and the bike didnt just have idle problems, it blubbered, and WOULD NOT hold an idle...in other words you always had to be on the gas.

about the jetting too...

after experiencing what seemed to be always rich conditions(my 88 xr600 had a stock 165main) with twin exhasuts...I finally decided to keep down jetting till I got it right.

went down from a 65pilot to a 62 and from an inital 160 main to a 152 now it works! powercore 4 and uni...

cheers

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went down from a 65pilot to a 62 and from an inital 160 main to a 152 now it works! powercore 4 and uni...

I still can't figure out why your bike only wants a 152 main, but if it works, it works. Compare that to my 68/170. :busted:

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yup its weird...but if you think about it I haven't done any mods to warrant a huge upjet.

powercore 4 and a uni ...yeah It might breathe a bit better but my head and stuff is all stock except for kibblewhites...

anywhoo

I fought and fought and fought with black smoke...blip, blubbery...

when I went up to 5000feet it became worse so I really now knew that i was too rich, so steve sent me a 152 main...stock, its even an xrl jet and it works just fine go figure!

anywhoo

thats my story...

its much crisper, and throttle is instant...even that off idle bog seems to have become much less pronounced...

cheers HT!

christian

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Must be a number of XR/XR-L running lean in the States..The used XR600 carb I got off Ebay and imported down here had jetting of 138 and 65...I kept trying to imagine it read 158..but no, magnifying glass inspection confirmed 138..I've since changed it to 162/62 but it's too rich,, does the blubbering and needs no choke to start so I'm waiting on a 58 pilot to see how it goes with that..Only real mod that bike has on it's the CRF250-X Muffler though the cylinders bored out to over a 100mm...(0.25 oversize XL600 piston) Not sure which bore it is XL or XR-L , I didn't need to do any boring of collets to get things to fit together as one imagines you do with swapping bores/heads around so I'm still perplexed on what bore I'm actually using..Cylinder liners kinda slim on leftover metal with the 100 in it,,seems to run ok however..

Edited by Horri

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Also, your old carb did not likely need to be replaced, but simply cleaned if the ACV wasn't ruptured. I have not experienced a ruptured ACV yet, but others have indicated that it causes idle mixture problems.

What is the ACV

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Also, your old carb did not likely need to be replaced, but simply cleaned if the ACV wasn't ruptured. I have not experienced a ruptured ACV yet, but others have indicated that it causes idle mixture problems.

What is the ACV

It does, I changed mine a couple of days ago and the bike idles better but not perfect yet. At least it does idle though. The ACV is the air cuttoff valve on the carb. Its a diaphragm behind a circular cap on the side of the carb.

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Thanks to everyone who helped me i put in a 155 and the needle on the 4th clip goes heaps better

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What is the ACV

Air Cut Valve. It richens the mixture on deceleration by cutting air to the pilot jet's emulsion holes. The effect is less engine braking and better transient throttle response

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I still can't figure out why your bike only wants a 152 main, but if it works, it works. Compare that to my 68/170. :banana:

Hey Head Trauma, what are your filter/exhaust set ups? I love my 68, but i made an intake with a UNI twin filter pod, and i either need to upjet from 165 or restrict air. I ordered a 160-170 jet packet to play with and I have a 175 to try (tomorrow) but that sounds big. My top end chokes and i mostly do freeway miles in so-cal. My low and mid range is better in any needle position.

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