'06 Cam in a 400?

Not to hi-jack a thread but my buddy just obtained a 99 YZ400 that has 10hrs on a new top end, including cylinder, and new tranny. I could not go with him to check out the bike so he bought it. Well the bike has milky white oil, water leak obviously, and is in rough shape none the less. The bike does run good and was thinking of doing the auto decomp mod for him as well. I was looking at the hot cams web site and the sticky about this mod and noticed the hot cam for the mod is a 03-09 yz450f exhaust cam. I have the stock exhaust cam out of my 06YZ450 and was wondering why they would not work if the hot cam uses a 03-09 cam? Thanks!

I also noticed that the 06 YFZ450 cam would work in the wr400. Does it have to be the 06 Cam specifically? Would any one of the YFZ450 exhaust cams works? I got the bike apart and am in the process of replacing the top end since it was not just rebuilt as my buddy was told. ARGHH!!!! I am still wondering if the 06YZ450 cam would works as well? Thanks again!

The most popularly used cam for this swap, other than a Hot Cams, or other aftermarket part made for the task, is the '03-'05 YZ450F cam. That gives you a performance boost while adding auto decompression. The same year WR cam can be used to get AD without the aggressive timing. Quad cams are like the WR cams, mild timing, etc. The YZ450 cam for each year from '06 upward is progressively more biased toward top end at the expense of low speed pull and smoothness of operation. The '06 YZ450 cam is not so aggressive that it would be unacceptable, I don't think, but it will be more focused on the upper mid range than the '03-'05 cam is.

Remember that none of the OEM 450 cams made for use in 450cc engines can be timed strictly buy the marks as a stock cam is. See the instructions and clarification in Common Threads.

I appreciate the insight on the cams. My buddy that bought the 400 is coming off a 96 RT180 so even if the bike does not get the power gains from the 03-05 cam, I will install my old 06 yz450 cam and go from there. I dont think he will miss any low end power since he is coming off the old RT. Thanks again!

Well after I realized my buddy was lied to about the rebuild I tore farther into the motor and found a few more items needing attention "alot of aluminum shavings in the oil filter". I noticed there was a rub mark on the clutch cover from the pressure plate. It looks like the previous owner took a spill and hit smack dead center of clutch cover causing it to rub on the clutch. Then I tore the right side crankcase cover off and found this:



And the cylinder







The motor was full of this yellow milky oil.



Well I just came in from the garage and was going to remove the rear sub frame and noticed that someone welded it to the frame! ARGHHHH!

This is going to be a long ride.

This is going to be a long ride.

Your right in saying that. Good luck with it and any more surprises you will find

Well I finally got the bike back together and the damn thing wont start! Arghhh! I installed the exhaust cam from my 06YZ450 and it kicks over real nice now but she wont fire. I checked the spark and it's good, the timing is the way it's suppose to be and I checked the valves. After I installed the 06 cam is the exhaust cam still suppose to be shimmed to the YZ400 specs or the 450 specs?


Well after about a couple hours I found that the orange wire coming out of the bottom of the coil was grounding out against the frame and the rubber gromet around the plug was cracked. After a few short lengths of good old electrical tape she fired up 1st kick. Now it's time to attack the forks and shock. I had to order a swingarm because the original one is cracked, an air box because the one on the bike is held together with JB weld, a subframe because the one on the bike is welded to the frame right above the shock and a kill swith since it does not have one. I am hoping to have this bike done by friday and out of my garage. I am still debating wether or not to buy a coil since the plug boot is taped together. After all is said and done my buddy will have $1600($1000 for the bike and $600 worth of parts)into it. This will be a nice upgrade from the RT180.

Scout ebay for used parts, you will be surprised what you can find sometimes. Although if you are in a rush to get it running than it probably wont help much

Ebay is how I got every thing for $600 or else it would have been way more than that. I'm not in a hurry on this one because his RT180 has been in my garage for 2 years now off and on with various repairs. I got the forks apart last night and both tubes had no fluid in them. The rubber bumpers below the fork cap fell out when I pulled the spring down to remove the cap. It was not pretty!

I had some time and a few old signs from work and decided to fab up some rad guards for the YZ400. What do you think?

This is what I started with:


Then after I used the vice to make my bends:


She fit like a glove:


I then had to drill the holes and even drilled a YZ on the top:


Final fitting:



Your a good friend. You in Norcal or Socal?

I live in Nor-Cal and Sacramento area to be more specific.

that is a pretty sweet idea! never thought about that even. the 'yz' logo is cool too. u should try to find a way to distinguish it just a lil more. paint perhaps?

Hey, That's where that sign went! I couldn't figure out where the restroom was last time I went to Mammoth...

I thought about using my plasma cutter and actually cutting this into the guard instead of smaller holes. Oh well, I also have a piece of 3/16 304 stainless sheet that I'm gonna attempt to fab up a skid plate for him also. Yeah, I have extra time on my hands right now so why not.

hey with free time its always fun to get creative. plus your saving money and makin the bike more unique!

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