'05 WR450-Cam Pin Grind?


8 replies to this topic
  • MarshalGiles

Posted March 07, 2008 - 02:11 PM

#1

I was hanging out in the wr250f forum and caught the end of a thread talking about grinding the exhaust cam decompression pin 1mm to enable the cam to be rotated to YZ timing. I understand the idea, but haven't heard of anyone doing this to their 450 as of yet. It appers a few people have done this to their 250's with no problems so far. Anyone tried it? Did it cause any ill effects? Can this mod even be done to an '05 WR450 (basically, are the yz/wr cams the same except for the decomp pin length)? Also, is it possible to just order the decomp pin from a YZ cam and just replace that?

I still haven't decided whether or not its a good idea to be doing this, but I'm just trying to find out as much as I can. Hey, if it's easy and saves $100+, then I'm all for it. I did a pretty extensive search (I think) and didn't find much at all. Thanks for your input

  • MarshalGiles

Posted March 08, 2008 - 05:28 PM

#2

Nobody has heard of this before?

  • maxtherat

Posted March 08, 2008 - 05:35 PM

#3

I don't know about the 250, but the 450 you need to use the cam from a yz to get yz cam timing. If you use a wr cam and retard the timing to try to get yz timing your electric start will not work properly.

  • MarshalGiles

Posted March 08, 2008 - 06:40 PM

#4

I don't know about the 250, but the 450 you need to use the cam from a yz to get yz cam timing. If you use a wr cam and retard the timing to try to get yz timing your electric start will not work properly.



Yes, I realize that. Actually, the issue with timing a WR cam to YZ specs is that the decomp pin is either the wrong length or in the wrong place for the electric start to work. I was asking if there was a way to modify the stock WR cam (grinding the decomp pin) to allow for it to be timed like a YZ. I just thought that someone here would have done it before and have a definitive answer.

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  • freerider_australia

Posted March 09, 2008 - 09:02 PM

#5

i did the nipple grind on my wr250 cam then set it to yz timing it works and is a worth while mod
i have not checked the 450 yet you could check the wr timing spec and compare it with the yz450
i havet checked yet as i think the wr450 has plenty of power

  • dirtysouth

Posted March 10, 2008 - 12:36 AM

#6

I was hanging out in the wr250f forum and caught the end of a thread talking about grinding the exhaust cam decompression pin 1mm to enable the cam to be rotated to YZ timing. I understand the idea, but haven't heard of anyone doing this to their 450 as of yet. It appers a few people have done this to their 250's with no problems so far. Anyone tried it? Did it cause any ill effects? Can this mod even be done to an '05 WR450 (basically, are the yz/wr cams the same except for the decomp pin length)? Also, is it possible to just order the decomp pin from a YZ cam and just replace that?

I still haven't decided whether or not its a good idea to be doing this, but I'm just trying to find out as much as I can. Hey, if it's easy and saves $100+, then I'm all for it. I did a pretty extensive search (I think) and didn't find much at all. Thanks for your input



Buy a YZ cam then do the Mod to your cam. If it works then you are golden and you can take the YZ cam back. If it doesn't...you have a backup:excuseme: I have seen the cams pretty cheap. The most that I have ever seen them to be is like 155...they are usually around a benjy though. Mod sounds legit though when you think about the effects.

  • MarshalGiles

Posted March 10, 2008 - 03:54 AM

#7

That's a good idea. I heard from someone over on the 250 side that the cam blanks were different between the 450 cams. I haven't been able to confirm that, though. I guess I can compare them when I get a YZ cam.

  • dugabrams

Posted March 10, 2008 - 12:23 PM

#8

I don't see how grinding the pin would advance it's location the single tooth neccessary to allow for yz timing. I think the better fix would be to add length (maybe weld) to the YZ pin.

  • MarshalGiles

Posted March 10, 2008 - 05:35 PM

#9

I don't see how grinding the pin would advance it's location the single tooth neccessary to allow for yz timing. I think the better fix would be to add length (maybe weld) to the YZ pin.


You should read this thread to understand how it works




 
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