450 hotcam in yz400f HELP!

[maverick_26]

I have a 1998 yz400f and I purchased an exhaust hotcam for it from (yamaha of troy). I purchased one for the 400/426 and they for some reason sent me a hotcam for a 03+ yz450. I found that I can make it work but the timing marks are totally different and just wanted to find out how to time it right. Please help. I gotta get it running again

[SDBSKI]

Does it have the auto decompression mechanism on it?

[642MX]

I have a 1998 yz400f and I purchased an exhaust hotcam for it from (yamaha of troy). I purchased one for the 400/426 and they for some reason sent me a hotcam for a 03+ yz450. I found that I can make it work but the timing marks are totally different and just wanted to find out how to time it right. Please help. I gotta get it running again

Rotate the exhaust cam counter-clockwise one tooth from the stamped timing marks.

[642MX]

I found a picture that may help. Scroll down in this thread. https://www.thumpertalk.com/forum/showthread.php?t=245248&highlight=450+timing+picture

[maverick_26]

It has the auto decompression on it, are the 450 hotcams just like putting in a factory 450 cam? Are the timing marks the same?

[grayracer513]

You need to be certain that the cam is in fact for a 450, and does not look different simply because of the auto decompression mechanism, which will eliminate one of the three timing marks. The instructions 642MX posted are correct for timing a 450 cam in a 400/426, but if the cam you have was actually made for a 426, they're wrong. Check with Hot Cams before proceeding if there's any question.

[maverick_26]

Well, i'm sure its a 450 hotcam but what i'm not sure about is if the hotcam has the same timing marks as the actual oem 450 cam. If they have the same marks it doesnt look like it will be that hard. Just line up the 9:00 mark to the head and turn 1 tooth counterclockwise right?

[grayracer513]

No. The right way is to first be certain that the intake cam is correctly timed. Then count 14 pins between the 12 o'clock marks on the two cams.

[maverick_26]

Should I just give yamaha of troy a call and get the yz400f hotcam? Will the timing be any different from the yz400f hotcam if I do use it? If I dont want to use it does anyone want to buy a yz450f hotcam? lol

[grayracer513]

I know for a fact that the OEM 450 cam works very well in the 400/426. I also know that the Hot Cams unit for the 400/426 works well. The Yamaha cam works better than the Hot Cams cam if the HC is used by itself (it works better when paired with the Hot Cams intake).

But what I'm not certain of is how the Hot Cams 450 cam will work in the earlier engine. I should be alright, but I just don't know.

If it were me, I would return the cam and have them send you the one you asked and paid for.

[642MX]

But what I'm not certain of is how the Hot Cams 450 cam will work in the earlier engine. I should be alright, but I just don't know.

I've had one in my 426. They work fine.

I have both of the 426 Hot Cams in there now and its a better combo, but the HC 450 exhaust cam will work.

[maverick_26]

642MX, for timing did you need to count the links between the 12:00 marks when you used the 450 hotcam why did you get rid of the 450f hotcam?

[642MX]

642MX, for timing did you need to count the links between the 12:00 marks when you used the 450 hotcam why did you get rid of the 450f hotcam?

Don't count the links, count the pins.

Yes, count the pins between the 12 o'clock marks. Make sure the intake cam is timed correctly before you drop in the exhaust cam. There should be 14 pins between the 12 o'clock marks.

Its actually very easy to do. Just take your time and ask questions if your uncertain about the job. If you want to put it in time and post a picture we can tell you if its right or not.

And don't forget to reshim the exhaust valves, they will mostlikely be too loose with the 450 cam and you'll have to add some larger shims.

I removed the 450 cam because I found a deal on a couple of the 426 Hot Cams.

[maverick_26]

Will the 450 hotcam give as much performance as an 03 oem 450 cam? Your sure 14 pins is right? I've heard 12, 13, and 14.

[642MX]

Will the 450 hotcam give as much performance as an 03 oem 450 cam? Your sure 14 pins is right? I've heard 12, 13, and 14.

14 is correct for timing a 400/426 with a 450 exhaust cam. Look at the picture in the link I posted earlier.

The 450 Hot Cam will perform nicely, you'll like it. The power is best described as "broad". It seems to pull longer and smoother with the cam.

[maverick_26]

Which would be better?

--Hotcams yz450 dc exh cam with yz400f hotcams intake cam

--Hotcams yz400f dc exhaust cam with yz400f hotcams intake cam

--Oem yz450 dc exhaust cam with yz400f hotcams intake cam

Will the hotcams 450 cam hit as well as the oem 450 cam? Whatabout paired with a yz400 intake cam?

[642MX]

Which would be better?

--Hotcams yz450 dc exh cam with yz400f hotcams intake cam

--Hotcams yz400f dc exhaust cam with yz400f hotcams intake cam

--Oem yz450 dc exhaust cam with yz400f hotcams intake cam

Will the hotcams 450 cam hit as well as the oem 450 cam? Whatabout paired with a yz400 intake cam?

The HC 450 cam performs almost exactly like the oem 450 cam. Not sure about the above choices....

[maverick_26]

When you had the 450 hotcam how much of a difference could you feel? Could you still easily pull the wheel up?

[642MX]

When you had the 450 hotcam how much of a difference could you feel? Could you still easily pull the wheel up?

You won't loose any power with it. It just makes the power more broad and usable. Wheelies are not a problem.

[maverick_26]

Something I notice about the cam is wierd. I was comparing the lobes of the old exhaust cam and this cam and the lobes almost look the same, like the same shape pretty much. But the box says the 03-05 450 part number and says 03-05 yz/wr 450. Are the 450 lobes compared to the 400/426 supposed to look any different?