450 Cam mod wear issues?

[bfly]

After reading numerous posts about how to do the 450 Cam mod I am wondering how reliable it is. Reading ThumperFAQ I saw a comment about the mod for the 426 saying the tooth pitch is different enough to quickly wear out the cam and chain. ThumperFAQ is the only place I have read about this problem.

[GPS Dual Sport]

I got well over 1000 miles on the bike since the new caw went in.

Can't say anything about the cam wear issue. I installed the cam modified by CW with the correct pitch sprocket.

[yamaha.dude]

I have not heard a single mechanical issue arising from the 450 DCM Cam Swap...

David

[blue_beast_wins]

8500 ks with this mod, still looks great , dont know how it converts to miles, sorry. I think its more than fair to say that the tooth issue IS NOT an issue dispite what has been said by the "text book" engineers at Yamaha, maybee they should think more about making a gearbox that stays together as the mod has outlasted two 3rd pinion gears. If i had my time over, this would be the first mod i'd do !!

The Blue Beast awards this mod 4 thumbs up ?? and a beer or six ??

[Hamish]

ahhhh..here we go again ?

Yes the mod appears to be reliable and there are many people who have done it with no reported failures. I personally havent done it as I have no desire for auto decomp. At 6'3" and 210lbs the ol' 426 goes first kick every time. I also have my doubts about the chain/sprocket mismatch and expect to get shot down in flames for my comments After all, this is a forum for expressing one's personal opinions.

[bfly]

DCM?

[blue_beast_wins]

Hamish, not only does it start good you should feel the power curve, sensational !! and dont you hate it when you stall ? if i stall i only loose a meter or so, let the clutch go and it starts right up again unlike before with that funny lever you have to use next to the clutch lever, whats it called again.........thats right, manual decomp

Not shooting ya down mate ? just informing.

[Hamish]

and dont you hate it when you stall ?

no..not at all. I simply flick the decomp lever and away she goes again. As for the power curve, I'm led to believe that the auto decomp cam has a slightly better bottom end and a smoother transistion into the midrange. The hit that the YZ timed 426 has in the midrange is what I love about the bike. Would never want to loose that. Has anyone actually done back to back dyno runs on a YZ timed 426 to a YZ450 cammed 426?

[blue_beast_wins]

Has anyone actually done back to back dyno runs on a YZ timed 426 to a YZ450 cammed 426?

The dyno sheets on the pdf are taken from yamaben's Yz426

[John_H]

and dont you hate it when you stall ?

no..not at all. I simply flick the decomp lever and away she goes again.

I did this mod not because I had trouble with the manual deco or starting, but just because of the rave reviews from others.

I've probably got 1000 miles and some really great riding (lots of single tracks and tight mountain stuff) and really appreciate the auto deco specifically because of the ease of bump starting if I stall.

I've got a 12 oz flywheel weight, but occassionally if I charge into a corner or am heading off the side of a ridge or into a tree and crashing is immenent, I stall. Sure is nice to just let off the brake and have it start again. Don't even need to use the clutch.

Is it a must have mod like hand guards??? Not really.

Was it worth the time??? ?

[Hamish]

The dyno sheets on the pdf are taken from yamaben's Yz426

old stock engine vs fresh ported engine doesnt sound like a very fair comparison, providing we are talking about the same pdf?

[blue_beast_wins]

Actually the ports were deburred, not ported and it had a valve job but i doubt very much it needed it.

You probably havn't been here long enough to know that my brother had a Wr426 also, we had raced these bikes straight line back to back, his remained Yz timed and mine with the 450 cam mod, these bikes were always neck and neck, swap riders same result, the dyno sheet looks right to me, the 250 bucks was well worth it to get rid of that antitractable power of the Yz timing, ok if you like riding 2 strokes i suppose.

[John_H]

Hamish just doesn't know!

One day will reveal the benefit. ?

[blue_beast_wins]

Hamish just doesn't know!

One day will reveal the benefit. ?

Ditto John, thinking back that Yz timing was like flogging a dead horse

[Hamish]

Ditto John, thinking back that YZ timing was like flogging a dead horse

Without the YZ midrange hit, your bikes would feel more like a 'dead horse' than mine anyway.

A dead horse isnt all you guys are flogging ?

Try to come to grips with the fact that just because other people may not share the same view as you, it doesnt mean they are wrong.

[blue_beast_wins]

Ditto John, thinking back that YZ timing was like flogging a dead horse

Without the YZ midrange hit, your bikes would feel more like a 'dead horse' than mine anyway.

A dead horse isnt all you guys are flogging ?

Try to come to grips with the fact that just because other people may not share the same view as you, it doesnt mean they are wrong.

Wooooooow touchy, touchy,

Didn't think it would get nasty though it seems to be going that way, nothing beats "been there done that" exprience ?

Hamish: Never even seen a 450 cam ?

Blue Beast: thousands of miles with and without one ?

If you're not willing to try it, who am i to convince you, i dont give a flying ____ what your bike goes like or feels like, riderbililty is the key to the pace, smooth bike and rider = front runner, not that i am ?

No offence intended wouldn't want any "name calling" over our opinions though i am expecting it going by some responses.

Now back to the original Question thanks

[Hamish]

ok..seems like this thread is heading in the wrong direction. The point I was trying to make is that there are plenty of 426 owners that are happy with the way their bike performs (either wr or yz timed). If you are happy there is no need to change. If I raced enduro or even MX I would probably be quicker with the 450 cam, but I dont race I just ride for fun so it doesnt really matter.

[bfly]

I just finished installing the cam and love the new powerband. If you haven't ever ridden a bike with the mod then I think you should at least try it. It is much nicer than before.

Not stiring the pot, just an observation.

[Guest Georgiou]

Hi Steve,

i haven't been on this for while so you may have forgotten who i am. i was the guy having all sorts of trouble with the cam mod, and ended up getting someone to do it for me. then i got my hands dirty and re adjusted the timing myself, after reading that the tooth gap should be 14 pins...

i've ridden my bike quite a few times now, track riding, and i am really not oo sure about it. i THINK it goes o.k. but after every ride it seems to fowl plugs up, well on the day its fine, just when i take it out again i need to put a new one in. and im not too sure about the mid-top end, i think its missing some grunt.

what i would like to know is where you take your bike out to ride, becasue i would like to line them up, and get you to have a ride and look at it. i'm from melbourne myself, and generally go riding at bacchus marsh speedway.. if you get out for a ride sometime i would appreciate if i could meet you somewhere to have a look..

thanks mate,

Luke

wr426f '02 james now, squirt timing, yz450 cam

[Rip Wheeler]

I sold a 2001 WR426F with the "YZ timed camshaft, it made gobs of power, was a little tougher trail riding at the slower speeds. I didnt realize the difference. I have purchased a new 04 WR450F and I use it for trails also, and its perfect for trail riding. If I would of known how much tougher the YZ timed 426 was to ride in trails compared to WR timed, I'd put it back. It also makes more grunt off of idle. The 450 with the stock camshaft makes plenty of power as is. If your going to trail ride, the stock setup is great, if your going to race it, the YZ setup may be for you. My 426 was also revalved and resprung, it made it harsher riding in trails and would beat my shoulder joints up, the WR is smooth, but I'm a grandpa and dont ride too fast anyway! ?