Quick help please...Carburetor questions

11 replies to this topic
  • barch88

Posted June 16, 2006 - 09:13 AM


At first when I rode my new 06 it poped, the lean condition, yeah yeah...well now I moved up north, and it's a lot cooler up here, but I havent got to ride my bike yet because the plug is fouled and I now have time to work on it today. I called up my local shop/dealer and asked if they sell jets for the carb (Burned suggested a 48 pilot jet, leave all the others the same), he said I need to take my old jet out and then bring it for size comparisions. Can't I just tell him its a 06 YZ450F w/ Keihin carb, and I need a 48 pilot for it?

First time Im going to tear into the engine on my 450 (well, carb/engine area). I hear it's a lot harder to get to the jets on this one. What is the best, easiest way you guys found to get to the carb without ripping everything out?

And should I go with a 48, or since it's cooler now, should I go to a 47 or something? Isn't the stocker a 45? or 42? If I go too rich, is there another way I can lean it up without changing the jet, vise versa with too lean?

Also, one other question while Im out in town, should I be worried about the chain guide thing hitting the swingarm? I can put some silicon I have (caulk silicon, same stuff) on if I need to, but Im just unsure exactly where it needs to go, and how much, is there anything else that needs to be put on with the silicon?

Thanks A LOT for the help guys.

  • WFOracer

Posted June 16, 2006 - 09:44 AM


I went with Burned's reccomendations too. I will give mine the true test this weekend at the track. (got it saturday, and haven't had it our yet!)

Did you lube the ba-jesus out of it? My headset had almost no grease in it. So I went through them all, but the headset was the worst.

What is your eleveation? I went with the 170 main and 48 pilot. I am at about 900 ft.

I don't think that your swingarm will wear out after a weekend of riding, but it looks like it would be a good idea to do before long.

Grayracer mentioned that it was pretty easy to get to the carb it you take the gas tank, and upper engine mounts off and just tilt the carb. Probably want to disconnect the TPS and hot start. I did it the hard way and took the shock off. Not a big deal since I was greasing the linkage.

Good luck

  • barch88

Posted June 16, 2006 - 10:15 AM


Oh, yeah. I lubed the heck out of everything on it when I first got it about a month ago. I just haven't had any time to ride, but now I got all summer to ride/race.

Elevation: 613 feet

Thanks for the help on getting to the carb, well I thank both you and grayracer. How much are the jets for these bikes? If I get the 170 and 48 how much will it run me?

  • WFOracer

Posted June 16, 2006 - 10:46 AM


my bike came with the a 160, 165, and 170 main. (along with the manual, spoke wrench, etc)

The pilot was only $4-5.

I also hear that the stock chains are junkola.....probably a good idea to get one ordered asap if you plan on riding a lot now!

Good luck!

  • yami racer

Posted June 16, 2006 - 11:20 AM


The jets are about $5 each. You should have gotten the 170 and 160 main jet when you bought the bike with the manual. I would hold off on the the main and keep it stock as most of us are going back with the warm weather to the 165. But do replace the 42 pilot with 48.

  • WFOracer

Posted June 16, 2006 - 11:42 AM


The jets are about $5 each. You should have gotten the 170 and 160 main jet when you bought the bike with the manual. I would hold off on the the main and keep it stock as most of us are going back with the warm weather to the 165. But do replace the 42 pilot with 48.

What is your temp and elevation?

Where are you at on your fuel screw? thanks

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  • barch88

Posted June 16, 2006 - 11:52 AM


Alright, so I just went and bought the jet. I do have a 170 and 160 main that came with my bike also. So all I do is just got to take the stock 42 out, and then put the 48 jet in. Change my plug (it's fouled), and that's it? Is the "Pilot Screw" the fuel screw? Burned suggested I turn it 1.5 out.

  • yami racer

Posted June 16, 2006 - 12:07 PM


When I was racing with the 48/170 it was 45-65 degrees and 2 on the fuel screw. Now it is 80 to 90 degrees so I went 165 on the main and 1 - 1.5 on the screw and the bike rips. This weekend will be 95 so I am going to make the decision on the pilot and maybe go to a 45 but I will let you know. Oh, I race mostly sea level.

  • barch88

Posted June 16, 2006 - 01:35 PM


I removed gas tank, engine mounts, and Im stuck. I can't just tilt the carb because it is connected to the airbox vents...help?

  • Fastest1

Posted June 17, 2006 - 01:51 PM


Loosen both clamps, front and back. If that doesnt work the airbox is flexible enough to pull off of the back without removing the carb.

  • barch88

Posted June 17, 2006 - 06:52 PM


WOW, I feel like a moron. very easy guys. Thanks A LOT for the help. This is my first time working on a bike.

  • Fastest1

Posted June 18, 2006 - 09:37 PM


Congrats, now the fear is over.

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