450 hotcam in yz400f HELP!


32 replies to this topic
  • grayracer513

Posted April 04, 2007 - 12:11 PM

#21

You wouldn't be able to see the difference. A lot of it is in the timing relative to the intake.

  • maverick_26

Posted April 05, 2007 - 09:47 AM

#22

642MX, do you think the 450 hotcam paired with a 400f intake hotcam will work? Or should I just return the 450 hotcam and buy the oem 450 cam and use it with the 400f intake hotcam?

  • 642MX

Posted April 05, 2007 - 05:21 PM

#23

642MX, do you think the 450 hotcam paired with a 400f intake hotcam will work? Or should I just return the 450 hotcam and buy the oem 450 cam and use it with the 400f intake hotcam?


Either way, it will work. I'd keep the cam you have and install it. Get the intake cam later.

  • maverick_26

Posted April 05, 2007 - 05:31 PM

#24

I had to get a hotcam intake cam because somehow my stock intake cam gear spun on the cam so its waaay messed up.

  • Hot Rods

Posted April 06, 2007 - 06:08 AM

#25

the timing on any Hot Cam is YZ timing not WR. Go by the marks on the sprocket, dont retard it a tooth. We recommend using the 4002-1In and 4035-1E in the 4oo/426 (not the 450 cams) the sprockets are different between the 450and the earlier models. I dont mean just the timing, I mean the teeth. The chain looks like it fits ok on just 1/4 of the sprocket, but try wrapping it all the way around the sprocket, as compared to the 400 O.E. cam. Doesnt fit correctly. We have an auto decomp cam MADE FOR the 400/426. You should use that one.

  • 642MX

Posted April 06, 2007 - 10:23 AM

#26

the timing on any Hot Cam is YZ timing not WR. Go by the marks on the sprocket, dont retard it a tooth. We recommend using the 4002-1In and 4035-1E in the 4oo/426 (not the 450 cams) the sprockets are different between the 450and the earlier models. I dont mean just the timing, I mean the teeth. The chain looks like it fits ok on just 1/4 of the sprocket, but try wrapping it all the way around the sprocket, as compared to the 400 O.E. cam. Doesnt fit correctly. We have an auto decomp cam MADE FOR the 400/426. You should use that one.


When using any 450 exhaust cam (Hot Cams, OEM, ect...) the exhaust timing mark has to be rotated counter clockwise one tooth from the marks to work in a 426.

The Hot Cams 450 exhaust cam will work in a 400/426. I called Hot Cams customer service before I did it and you guys couldn't answer a straight question about it. Didn't know anything about it, and didn't offer to help. So I installed it and guess what? It worked perfectly.

Yes, the cam chain rides up on the cam gear with the 450 cam, but it doesn't cause any accelerated wear or problems. 1,000's of us have done it with no problems or issues. :bonk:

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  • grayracer513

Posted April 06, 2007 - 02:19 PM

#27

It is true that the specified tooth shape for the 426 and 450 cams/chains is different. This issued was debated and analyzed and re-hashed in depth and at length for months when the YZ450 came out. Since then, literally hundreds of people have installed YZ450 cams in their 426's and 400's, many of which now have 100's of hours on the engines, and not one to date has reported having any wear issues, or other valve train problems of any sort that could even remotely be attributed to the swap. None.

So, even though the technical facts are undeniable, the record speaks for itself. It's a non-issue from a practical standpoint.

  • Hot Rods

Posted April 09, 2007 - 01:28 PM

#28

When using any 450 exhaust cam (Hot Cams, OEM, ect...) the exhaust timing mark has to be rotated counter clockwise one tooth from the marks to work in a 426.

The Hot Cams 450 exhaust cam will work in a 400/426. I called Hot Cams customer service before I did it and you guys couldn't answer a straight question about it. Didn't know anything about it, and didn't offer to help. So I installed it and guess what? It worked perfectly.

Yes, the cam chain rides up on the cam gear with the 450 cam, but it doesn't cause any accelerated wear or problems. 1,000's of us have done it with no problems or issues. :thumbsup:


Hot Cams 400/426 cams are timed for a YZ 426.Hot Cams 450 cams are timed for a YZ 450. When using either set in the engine they were designed for, the timing marks ARE correct. If you want to put 450 cams in your 400/426, its your bike, we just recommend using the set that was designed for that engine.

  • 642MX

Posted April 09, 2007 - 05:42 PM

#29

Hot Cams 400/426 cams are timed for a YZ 426.Hot Cams 450 cams are timed for a YZ 450. When using either set in the engine they were designed for, the timing marks ARE correct. If you want to put 450 cams in your 400/426, its your bike, we just recommend using the set that was designed for that engine.


I'm pretty sure we all know that already, but thanks anyway.... :thumbsup:

  • grayracer513

Posted April 09, 2007 - 09:22 PM

#30

642MX, do you think the 450 hotcam paired with a 400f intake hotcam will work? Or should I just return the 450 hotcam and buy the oem 450 cam and use it with the 400f intake hotcam?

I would have replaced the intake with an OEM part for a 400 or 426, and used the OEM YZ450 part. However, inasmuch as you've gone to the additional expense of buying an aftermarket part for both of these, it really doesn't make much sense to do so and not to use the part custom made for the engine. All it will cost you, it seems to me, is the time it takes to make the exchange, unless I'm missing something. Then, you'll have the same cam grind with the correct marks and tooth profile.

The 450 cam will work, and work well, but the 426 version would just be simpler, now that you've already spent the money for it.

  • maverick_26

Posted April 22, 2007 - 09:21 PM

#31

I got it all sorted out. Bought the yz400/yz426 intake and exhaust cam. Started right up and runs great. I just need to work on the jetting now to get the evil bog out. Thanks for the help everyone!

  • pushingvws

Posted April 27, 2007 - 08:17 PM

#32

Being that so many comments we're made on this subject maybe you guys can answer a question for me.

I installed an intake and exhaust cam on my yfz450 and it seems to run good. There is definitally an increase in power.

Well we did my friends quad, same quad same cams. Then he took his quad to a shop to get it tuned up and dialed in.

The guy at the shop said we were in danger of floating a valve because we did not change the shims on the bike. We just dropped the new cams in and fired the bike back up. So he had to spend a couple hundred bucks to pay this guy to re shim/re tune his quad.

My question to you guys is.... on my quad that's running fine (back fires occationally) do I need to look into replacing the shims with the Hot Cams?

Thanks for your help.

  • grayracer513

Posted April 27, 2007 - 09:46 PM

#33

The shims would need to be changed only if the valve clearances were incorrect on installation of the new cams.

The only other consideration is whether the stock valve springs are adequate. If they were not, the information included with the cams would have stated that replacement springs were required.





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