2004 yz450 mods

I am sorry if this was mentioned in a previous post, and if it was I must have missed it.

I am running a straight from the factory bike, what are the mods that are recomended as a starter. I would be lieing if I was to say that I am getting all out of my bike that it has to offer now, but I am hoping to speed this learning curve up a bit :ride: Any help would be greatly appreciated, and if there are links that show examples of the mods, that would greatly help as well.

Thanks for your time,

Squishy

Come on fellas, hook a brotha up with the info :ride:

Suspension.Aftermarket gripper seat cover,bars and grips,tires,UNI air filter,non oring chain and sprockets,fuel screw.If you want more top end,remove the throttle stop on the RH side of the carb(you'll gain another 1/4 throttle top end).

Hey bruntz, Are you sure there is a throttle stop on the Yzf's?? I thought only the WR's had them??

Don

Hey bruntz, Are you sure there is a throttle stop on the Yzf's?? I thought only the WR's had them??

Don

They both have them, but only the WR throttle stop stops the throttle short of wide open. There is nothing to be gained from removing the stop screw on a YZ except linkage problems.

If you really don't want to reduce your chain maintenance to nearly nothing and have a chain that lasts multiple years, then by all means, get a non O-ring chain. Otherwise, get a Regina ORN.

The '04 is an only slightly civilized version of the '03. A lot of people find the bike much easier to manage with some extra flywheel weight. I recommend at least the GYT-R racing flywheel (pn GYT-5TA97-50-00), which is about 5 ounces heavier than stock, or the Dr.D 6 oz. Better would be either the Dr.D 8 ounce or the GYT-R Offroad (GYT-5TA97-50-50, 7.5 ounce). The advantage to the Dr.D is that you can freely interchange for a different weight at no charge other than shipping. The Yamaha stuff you buy outright. The flywheel weight DOES NOT slow the bike down in the least, from my experience, but it does a lot for the manageability.

The YZ450 likes FMF Power Bomb headers a lot, too. I've tried mine with 3 different mufflers, and while it works best with the FMF can and midpipe, the header is a big improvement by itself. It broadens and smooths out the power curve, beefing up the low-mid with no loss on top. This, again, makes the bike easier to use at no expense to its performance.

Suspension is always one of the best things you can do. The '04 fork was a big improvement over the '03, and a good shop can do a lot with them.

i am with buddy on the suspension, but bear in mind that a stock o4 Yz450f came equiped with spring rates for a 180 to 200 lb. rider.........but a revalve is always nice.

i like the stock gripper seat, i also have is a washable/reuseable metal oil filter and a twin air air filter.

I like micheline MS3 rubber on the front and have the MAxxis IT on the back, it is bulletproof

that is about it......oh yeah! pro tapers.

.. bear in mind that a stock o4 Yz450f came equiped with spring rates for a 180 to 200 lb. rider.........
170-190. Depends who you talk to.
They both have them, but only the WR throttle stop stops the throttle short of wide open. There is nothing to be gained from removing the stop screw on a YZ except linkage problems.

If you really don't want to reduce your chain maintenance to nearly nothing and have a chain that lasts multiple years, then by all means, get a non O-ring chain. Otherwise, get a Regina ORN.

I thought I needed an oring on my 250f,until I bought an ERT chain.An oring chain has a lot of unsprung weight and causes a lot of drag.For me,I ride only MX,I couldn't see the point of an oring.BTW on my 250f,I put on my ERT chain,and actually only had to adjust it once last season,and it didn't show hardly any wear.Actually,the ERT chain has more tensile strength than about 50% of the oring chains,all you gain is wear life index.The key,especially on a Yamaha I found out the hard way,is that when you replace the chain,also replace the rollers,the wear block and the swingarm rub plate,these all eat your chain when they are wore and they give you inaccurate chain tension readings.Have you taken the stop out of your 250F?I did,and I swear I gained close to a quarter throttle on the top.Haven't done it on my 450f,don't really need it,don't have tracks big enough to reach wide open in fourth.

Pro-Action dude that did my revalve said 180-200.....I believe Pro-Action dude. Plus, fits right into my fluctuating riding weight of 190-200 lbs. Please don't mess with my perceived perfection and balanced suspension, fella, or I will wish a nasty punt on you in your next vet moto.

:applause:

I thought I needed an oring on my 250f,until I bought an ERT chain.An oring chain has a lot of unsprung weight and causes a lot of drag.For me,I ride only MX,I couldn't see the point of an oring.BTW on my 250f,I put on my ERT chain,and actually only had to adjust it once last season,and it didn't show hardly any wear.Actually,the ERT chain has more tensile strength than about 50% of the oring chains,all you gain is wear life index.The key,especially on a Yamaha I found out the hard way,is that when you replace the chain,also replace the rollers,the wear block and the swingarm rub plate,these all eat your chain when they are wore and they give you inaccurate chain tension readings.Have you taken the stop out of your 250F?I did,and I swear I gained close to a quarter throttle on the top.Haven't done it on my 450f,don't really need it,don't have tracks big enough to reach wide open in fourth.
The throttle stop screw in either YZF does not stop the linkage until the slide has fully cleared the bore (it's as wide open as it can get). Yes, removing it will let the grip turn farther, but there's no point in it. If you got any performance gain whatsoever from doing this, it means your main jet was lean, and the extra lift on the needle at past full throttle is where the boost came from.

The Regina ORN or ZRH sealed chains are almost 4 ounces heavier than their premium RX3 non-sealed MX chain. Only half that weight can be counted as unsprung, and if you don't select your rear tire based on weight, I don't want to hear any more about it.

Tensile strength is far less an issue than people seem to think. 5000 psi should be plenty. The majority of chains that have tensile failures snapped because they were too tight to maintain slack throughout the suspension travel.

The drag thing is another red herring. At any given moment, only the 8 chain pins at the points where the chain is rolling onto or off of the sprockets are pivoting, and only the four at the front are being moved as much as 15 degrees. This simply does not produce any significant drag, and there is no solid data that I've ever seen to show that it does.

Run whatever you choose, but make your arguments on facts, rather that folklore. The truth is that the Regina ORH I have on mine has been there for two years, is less than 1% longer than a new chain, and has no tight links in it. And it runs as free as your ERT does. All I do is wash it in place and re-lube the exterior.

What eats chains is being set too tight to have clearance through the entire range of suspension travel, wear at the pins due to lack of lube and/or the presence of abrasives (or soft pins), or being run on a hooked over sprocket damaged by a previous chain. It can drag on external things all day long and do far more damage to the stuff it rubs against than anything that will happen to it. Only the cheapest chains in which the steel used to make the plates was not pre-stretched will actually stretch in in use. Most of what makes chains longer than spec is wear at the pins.

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