08 YZ450F Broken Housing around Pilot Jet...Help


11 replies to this topic
  • ZMoney520

Posted December 01, 2007 - 02:28 PM

#1

So, today I put on a DR. D exhaust and it was popping so I decided to change the pilot jet. While doing so, I noticed the white plastic spacer was turning and covering up the pilot jet slightly. I then took off the bowl and removed the plastic spacer. When I did, part of the wall that the pilot jet goes through was broken (not from the factory, I believe I did this while trying to remove the jet) and now the white plastic spacer turns and covers the jet.

Has anyone every had this problem, heard about this problem, etc? It am hoping that this portion of the carb can be bought separately. It looks like the carb is in 3 pieces, the bowl, this section and the main body of the carb. But, I looked up drawings of the carb and it doesn't show this part serarated and I don't see any screws that hold it together. Has anyone disassembled a carb completely and know if this is a separate section?

PLEASE HELP.

  • grunkthump

Posted December 01, 2007 - 07:05 PM

#2

that SAME thing happened to me when changing the PJ on my new 07'....NO worries...the bike seems unaffected by it. I also spoke with someone at zip-ty racing about the problem...( I was worried I had cracked the ENTIRE carb body)...he also said NO worries...I think if a guy really wanted he could install the Merge floatbowl and probably remove the white plastic piece entirely?? Not sure.

  • dewercs

Posted December 01, 2007 - 08:27 PM

#3

I haven't had that problem...YET, but what ever you do DO NOT drop your carb on concreate, i dropped a yz250f carb and cracked the main body, you can't buy just the main body, you have to buy the whole carb I checked everywhere, I found one on e-bay for $130 bucks, a whole lot better than $900

  • ZMoney520

Posted December 06, 2007 - 06:31 PM

#4

Just wanted to tell everyone to be very careful when changing the pilot. Either get the right tool or take the carb off enough to see what you are doing.

I contacted ZipTy and Steve quickly responded to my email. He asked around and didn't know anyway to fix it and wasn't sure how it would affect the safety or performance of the bike. He pointed me in the direction of a carb place in Los Angelos. I talked to them and they told me the part couldn't be purchased, had no used ones, and the entire carb would have to be purchased fromYamaha to get the same carb. He did tell me if I could find a used carb and tried to change this part of the carb out that it has a special gasket that breaks 99% of the time and can't be bought.

So, Steve then pointed me in the direction of R&D Racing to ask them how it would make the bike perform. I called them and they said, "yeah buddy it will affect it". Not a good thing.

To sum it up, I HAVE TO BUY A BRAND NEW CARB FOR MY 2008 BIKE. :thumbsup: Can't wait to get it though. Had to buy a new exhaust thanks to a goon rider and I haven't gotten to try the DRD out yet. I was riding with White Brothers, so i am excited to see what the difference is.

Thank goodness my dad owns a Yamaha shop. :busted:

  • Ga426owner

Posted December 07, 2007 - 08:06 AM

#5

I assume you are G and V Roberts son eh? G.R. Jr I luv SYD
What did you use to remove the pilot? a too large flathead screw driver? :thumbsup:

  • grayracer513

Posted December 07, 2007 - 09:45 AM

#6

I'm assuming that what's broken is the cast-in tube extension that the jet screws into, and that it's broken below the jet. Understand that the function of this extension is to create a small, stabilized pre-chamber in the bowl for the pilot jet to meter from. Its presence may or may not be critical, but its size is not.

If this were my carb, and I'm very glad it's not, this is what I would do (I have a major aversion to spending tht kind of money):

Determine as nearly as you can what the original length of the extension was. You will want to duplicate that as nearly as possible.

Form a piece of 26-28 gauge stainless steel sheet (from surplus racks at metal supply stores, or any other source) into a tubular shape and cut it so that it can be glued in place against what remains of that area of the carb body.

Thoroughly clean the carb body and the metal sheet with brake cleaner, and rough up the body where the part will be glued with a knife blade.

I would use the two part epoxy from Loc-Tite for this job. It's similar to JB Weld, but I frankly have much more faith in the Loc-Tite product. Glue the part to the carb body, applying glue to the entire contact area, and then over the edges.

That the side of the tube may be open slightly is not as important as it may seem, but you could also seal it up with some of the epoxy. Allow 48 hours cure time in open air at room temperature or higher before trying it out.

It may not work, but if it does, you could save big.

Good Luck.

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  • SXP

Posted December 07, 2007 - 02:33 PM

#7

Why don't you post a picture so we can gauge the extent of the damage.

  • todds924

Posted December 07, 2007 - 04:22 PM

#8

Just wanted to tell everyone to be very careful when changing the pilot. Either get the right tool or take the carb off enough to see what you are doing.

I contacted ZipTy and Steve quickly responded to my email. He asked around and didn't know anyway to fix it and wasn't sure how it would affect the safety or performance of the bike. He pointed me in the direction of a carb place in Los Angelos. I talked to them and they told me the part couldn't be purchased, had no used ones, and the entire carb would have to be purchased fromYamaha to get the same carb. He did tell me if I could find a used carb and tried to change this part of the carb out that it has a special gasket that breaks 99% of the time and can't be bought.

So, Steve then pointed me in the direction of R&D Racing to ask them how it would make the bike perform. I called them and they said, "yeah buddy it will affect it". Not a good thing.

To sum it up, I HAVE TO BUY A BRAND NEW CARB FOR MY 2008 BIKE. :banghead: Can't wait to get it though. Had to buy a new exhaust thanks to a goon rider and I haven't gotten to try the DRD out yet. I was riding with White Brothers, so i am excited to see what the difference is.

Thank goodness my dad owns a Yamaha shop. :busted:


Hold off on buying that carb just yet! I may have one thats the same. At least the bottom part that you need. I will check it out at work tomorrow. It came off a CRF 250- 2006. The top housing where the cables go in broke on this one.

  • ZMoney520

Posted December 08, 2007 - 08:06 PM

#9

GA426Owner, close but no cigar. My dad's shop is in Rome, Ga.

Thanks for the help everyone, but I got the new carb today and it is already on. I feel a lot better having a new one on there rather than one I have McGyver-ized. When hitting the bike jumps, I don't want to be worried about anything. Know what I mean?

Not really sure how I broke it though. The screw driver fits in fine. I did it a little differnet that time though. Using pull the sub frame and rear shock, unhook the carb and work on it that way. But this time I followed something else I read and removed the motor mounts and rotated the carb. I guess I had the screw driver at a wierd angle and it grabbed and snapped it off.

Anyway. The knew carb is on now and I am excited to get out and see how the new DRD exhaust compare to the White Brothers that got trashed when I landed on a goon rider. By the way, if you know anyone that needs the exhaust part of a White Brother Al Pro 2 and not the header, I have one.

  • reed1

Posted December 09, 2007 - 09:10 PM

#10

I haven't had that problem...YET, but what ever you do DO NOT drop your carb on concreate


When im planning on dropping my carb ill drop it on grass:thumbsup: .............................although grass might be hard to find in az??

  • Ga426owner

Posted December 10, 2007 - 07:00 AM

#11

GA426Owner, close but no cigar. My dad's shop is in Rome, Ga.

Thanks for the help everyone, but I got the new carb today and it is already on. I feel a lot better having a new one on there rather than one I have McGyver-ized. When hitting the bike jumps, I don't want to be worried about anything. Know what I mean?

Not really sure how I broke it though. The screw driver fits in fine. I did it a little differnet that time though. Using pull the sub frame and rear shock, unhook the carb and work on it that way. But this time I followed something else I read and removed the motor mounts and rotated the carb. I guess I had the screw driver at a wierd angle and it grabbed and snapped it off.

Anyway. The knew carb is on now and I am excited to get out and see how the new DRD exhaust compare to the White Brothers that got trashed when I landed on a goon rider. By the way, if you know anyone that needs the exhaust part of a White Brother Al Pro 2 and not the header, I have one.


Ah Rome...I have purchased bikes through you all. Great dealership! How many hrs are on your WB exhaust? I may have a buyer for you. Keep your original carb - there are many that need parts for a OEM FCR = it will be easy to sell.

  • grunkthump

Posted December 10, 2007 - 02:02 PM

#12

not sure why you didn't heed my advice...that shroud around the pilot makes NO perceiveable difference!! I broke mine off when new also, and the bike runs perfectly. I guess if you felt it was a safety issue....





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