Corked or Uncorked??


9 replies to this topic
  • gslk1214

Posted February 27, 2006 - 05:35 PM

#1

Corked or uncorked, what does this mean?? I am new to this forum, and have not heard this term before, can someone fill me in please??

Thanks, Gord

  • TimBrp

Posted February 27, 2006 - 05:56 PM

#2

Now a days when you buy a new bike they are made to pass certain EPA govt. standards. The exhaust, fuel, airbox are plugged up, or "corked up" if you will. Removing these and restoring the proper air/fuel ratio results in a more efficient running machine, or "uncorked". Un-Corked is the only way to run them right. Welcome to the forum, did you buy a pig?

  • HawkGT

Posted February 27, 2006 - 06:00 PM

#3

Concerning the XR650R, "corked" refers to the state of tune the bike comes showroom-stock. The stock carburator intake manifold has a restrictor in it and the airbox has a couple of intake inserts in place. Honda makes an unrestricted manifold and the airbox inserts can be removed. There is a Honda free flowing exhaust tip also (commonly called the HRC tip). Stock jetting is lean to compliment these restrictions.

This is done for emmisions reasons. Honda specifically mentions "...lean carburetor settings as well as other systems..." in reference to emissions in the factory service manual.

Uncorking means fixing the restrictive stock settup so the bike can perform as it was designed.

  • chicagobikefan

Posted February 27, 2006 - 06:04 PM

#4

No such thing as a stupid question. The XR650L comes from the factory with a very, very lean condition. "Lean" means that there is less fuel per unit of air. "Rich", the opposite of "lean", means that there is more fuel per unit of air. The ideal mixture is between "lean" and "rich". The main reason why the L is lean is because the intake and exhaust are very restricted by a low-flowing air filter, a restriction in the intake box called the snorkel, and carburetor jets that are sized pretty small. The advantage of the lean condition is lower noise, low emissions, and good fuel economy. The disadvantage is a lack of power, plain and simple.

We all call this stock lean condition "corked", as if there were a cork in the exhaust or the intake, restricting power. When we say the bike is "uncorked", it means we have modified it so that it is able to breathe better and introduce more fuel into the mixture, making it start easier and run with much more power, albeit at the expense of fuel economy.

Common modifications are to replace the air filter with a better one, remove the snorkel in the intake box (under the seat), change the jets in the carburetor with 55/158, 55/162, or 58/165, and replace the exhaust with an aftermarket version. **Warning** if you make changes to the intake and exhaust, you will need to increase the carburetor jet size because if you don't the bike will run so lean that you run the danger of overheating the engine. Here's a video I made of how to change the jets in your bike.

http://www.violetinf...m/davesmods.wmv

Use the search feature on this and other forums to find out more. These questions, and probably many others you have, have already been asked and answered many times. Good luck!

  • goblin127

Posted February 27, 2006 - 08:34 PM

#5

No such thing as a stupid question. The XR650L comes from the factory with a very, very lean condition. "Lean" means that there is less fuel per unit of air. "Rich", the opposite of "lean", means that there is more fuel per unit of air. The ideal mixture is between "lean" and "rich". The main reason why the L is lean is because the intake and exhaust are very restricted by a low-flowing air filter, a restriction in the intake box called the snorkel, and carburetor jets that are sized pretty small. The advantage of the lean condition is lower noise, low emissions, and good fuel economy. The disadvantage is a lack of power, plain and simple.

We all call this stock lean condition "corked", as if there were a cork in the exhaust or the intake, restricting power. When we say the bike is "uncorked", it means we have modified it so that it is able to breathe better and introduce more fuel into the mixture, making it start easier and run with much more power, albeit at the expense of fuel economy.

Common modifications are to replace the air filter with a better one, remove the snorkel in the intake box (under the seat), change the jets in the carburetor with 55/158, 55/162, or 58/165, and replace the exhaust with an aftermarket version. **Warning** if you make changes to the intake and exhaust, you will need to increase the carburetor jet size because if you don't the bike will run so lean that you run the danger of overheating the engine. Here's a video I made of how to change the jets in your bike.

http://www.violetinf...m/davesmods.wmv

Use the search feature on this and other forums to find out more. These questions, and probably many others you have, have already been asked and answered many times. Good luck!

Thats perfect!

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  • wr450fyamaha

Posted February 27, 2006 - 08:43 PM

#6

Thats perfect!



I second that!

  • gslk1214

Posted February 28, 2006 - 06:11 AM

#7

Thanks for all the info guys. The cork thing makes sense now. Should maybe wait until the warranty is up before doing that?? Anyways, thanks again. I really enjoy this site, it is awesome!!

Gord

1982 Yamaha DT175
1982 XL185S
2006 XR650L

  • TimBrp

Posted February 28, 2006 - 06:39 AM

#8

Thanks for all the info guys. The cork thing makes sense now. Should maybe wait until the warranty is up before doing that?? Anyways, thanks again. I really enjoy this site, it is awesome!!

Gord

1982 Yamaha DT175
1982 XL185S
2006 XR650L


I wouldn't wait. Your bike is running unneccessarily lean as it is which may be detremental to your bikes health.

  • Motosprtman

Posted February 28, 2006 - 06:45 AM

#9

I bought my 05 XR650L almost a year ago - come March. I went back and forth on leaving it alone or uncorking it, I started with the rpelacement of the paper stock filetr witha UNI foam filter and then removed the smog stuff and installed the IMS kit (from Baja Designs) it was sorta different - but not much. Next I installed the dynojet kit - took the plunge, the kit comes with a new needle and e-clip a washer for over the top of the needle and 2 jets a 160 for running with stock pipe and a 165 for an after market. Now my bike began to change, strated easier mayb e just a wee more power. The finale.. I ordered a White Brothers E2 series pipe and installed it, that cinched it. WOW! the bike cam alive!!!!!! and the sound level is just a bit more than stock and sounds really good, roll on power is immediate and effortless, the engine seems bored just going thru the gears to 55-60 and loafs when it arrives at speed. Roll on the gas after a shift into 2nd gear and the front end comes up and will stay up as long as you hang onto the gas. I have uncorked 2 different bikes in my stable the XR250R and the XR650L and both are nothing like they were stock.

  • Motosprtman

Posted February 28, 2006 - 06:48 AM

#10

forgot to mention that I am going to drill my slide on the 650 next and try a 55 pilot jet for better cold start performance, while I am there I will install the 165 main jet, but running the 160 main with the white brothers pipe is giving me a good plug read, nice and tan witha white tip so maybe just a little bit lean and the 165 main may correct that I am thinkin, also have some Kehein jets on the way to try. But I will try the DJ 165 main and a 55 pilot nd see what I get. Maybe even more grunt!?





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