options for auto-decompressor cam 426

[ifurlong]

I want to install an auto decompression cam in my 02 426. how many aftermarket companies offer one and who are they? thanks.

I looked at the hotcams part and they claim more mid and upper power, I dont want that, if anything I want more bottom and smother power.

I am asking about an aftermarket offering because after reading many pages of this fourm I cant figure out if the 03 450 cam works right (different tooth pitch) or not.

[Dano426]

The 03 450 cam mod works. I have been running it for four years without any unusual wear on the cam or cam chain. The 03 cam mod does not smooth out the power, just the opposite.

You need to look at a flywheel weight to get smoother power.

steahlyoffroad

[grayracer513]

The OEM 450 cam works fine, and delivers a wider, smoother power curve without the spike the 426 has stock.

While it is true technically that the chain is a different pitch, that difference is very small, and of the probably hundreds of people using the OEM Yamaha cam, no one I know of has reported having any problem develop that remotely relates to that, unless you count just using the old chain for tool long a time regardless of the cam swap. Besides, you can get the OEM for about $100 through TT OEM Parts.

[ifurlong]

thanks, how do I order the cam from TT. since you mention it, I wanted to install a 12oz flywheel, is this a bolt on part? where do I get one?

[Zique]

ZipTy makes one -- Flywheel Weight

This is just the first one that came up on a google search. There are a bunch of companies that make them. Search google and find the one that best suits you and your pocketbook.

[grayracer513]

thanks, how do I order the cam from TT.

Go to:

http://oem.thumpertalk.com/

Follow the instructions to join (there's a membership fee, like other wholesale clubs have). It will cost you $10 for a year, but you'll still save $30 or more over retail AFTER the membership AND the shipping. The service is great, too.

[Dano426]

thanks, how do I order the cam from TT. since you mention it, I wanted to install a 12oz flywheel, is this a bolt on part? where do I get one?

I had a SteahlyOffroad 12oz on my 426 and liked it a lot. You can by a complete flywheel that will just replace your stock one. You will need a Flywheel puller to get the job done. I also found a flywheel holder very handy to have. I picked mine up at the dealer.

[Zique]

Does anyone happen to have the p/n handy for the OEM 450 cam?

[spinblue]

What is the OEM weight of the flywheel for an 01 426?

TIA

[Vibeguy]

I also recommend the 03 450 exhaust cam for the 02-426 and can vouch for the reliability. If you are going to remove your manual decomp system I recommend the TT decomp plug to blank off the hole. The stock rubber plug is a PoS that will blow out.

[random hero]

would i need parts #2 and 15??

http://oem.thumpertalk.com/2003YZ450Fcamshaft.aspx

[yz426em]

Hey Zique 5TA-12180-00-00 is the part # for the 03 exhaust cam if that helps you out at all.

[grayracer513]

would i need parts #2 and 15??

http://oem.thumpertalk.com/2003YZ450Fcamshaft.aspx

#2, yes, of course.

But # 15 is the infamous OEM flying bore plug. They're really cool, 'cause you just never know when they'll come sailing out of place like a micro-frisbee and dump oil all over the right radiator. If you paint it orange, you can watch it as it takes off across the countryside.

Your alternatives are:

> Leave the decomp shaft where it is, being certain that the hairpin spring stays on the lever to keep it disengaged. You can take that a step farther by cutting the half-round stub off the inside end so you don't have to move the shaft to adjust the right exhaust valve.

> Use an 18mm steel or brass cup plug instead. These need to be installed properly (everything does), but work well, can be safety wired in, and cost less that $2.

> Use the Thumper Talk Bore Plug. Pricier, but very cool solution.

You will probably also need to adjust the exhaust valve clearance, but you won't know that until you get the cam in place.

[Zique]

Hey Zique 5TA-12180-00-00 is the part # for the 03 exhaust cam if that helps you out at all.

That's the one, thanks!