First ride on YZ450 today

I got out for the first time on my 05 YZ450 today. It was great after I learned how to ride 4 strokes again. It took about an hour and dumping the engine about 6 times before I realized that you must pull in the clutch coming into a curve in tight single track BEFORE you press the rear brake. If not, you will kill the motor instantly (throttle off decelerating and rear brake on = dead engine super quick). I eventually broke my old 2 stroke habits and the bike was a lot of fun. Awesome motor. My issues after ride one (for trail conversion) are:

1) If anyone has a Scotts damper mount, I'm interested

2) I need to get lighter springs (What is stock for the fork and shock???)

3) I may look into Fluidynes radiators since it's very hot in the south and our single tracks trails can get tight and make you ride a little slow. I've seen KTM 450s and 525s over heat. Do the Fluidynes really help?

4) I had a light fork seal leak so I picked up seals and wipers and took the forks off. These forks don't have the traditional nut the you remove to get the springs off. It looks like it takes some kind of special took to get the cap off so you can remove the springs. Any suggestions would be greatly appreciated. I will order a repair manual immediately.

Thanks everyone and buy the way, I rolled it off of the trailer this morning and it fired up FIRST kick. After I learned to pull the hot start lever in the woods and to be Positive that I was at TDC, it cranked 1st time 90% of the time.

Fun, Fun, it looks like I will enjoy this bike.


2) Remember, it's a MX bike, and thus is sprung for MX riding, not off-road. Usually set for about a 175 pound rider.

3) Save your money....get a product called Engine Ice. It's a coolant replacement, that you use instead of traditional Antifreeze/water mixture. You just drain out the old Antifreeze/water mix that's stock, flush out any remaining coolant with a gallon of Distilled water (you don't have to use the distilled water, but I did it) and pour the Engine Ice in straight (don't dilute).

The Engine Ice will allow the bike to get hotter without boiling over.....before my bike on a hot Summer day, on tight trails would begin to boil over a little bit. When I switched to Engine Ice, it's never sputtered again, in the same conditions. Engine Ice claims up to 50 degrees cooler, but I think that's optimistic...however much it drops in temperature, I don't know, but the stuff works. Cost's about $ 16.95 a gallon or so (lot cheaper than new Rad's!!)

4) Before doing all should have taken some old 35mm camera film, wrapped it around the fork tube lower leg, and ran it up and down inside the fork seal. You probably got some grit, or dirt up there that's letting it leak. The old film ran up and down will usually dislodge the dirt, and you'll have no more leaks....doesn't work all the time, but quite a bit.

1) Can't help ya with the Scott's....But I hear they work great.

Thanks for the info. I may try the film trick and put the forks back on anyway. I had an extra set of 03 YZ forks with weaker springs and I was hoping to change the springs, but the 05 forks look totally different than the 03s so I doubt that will work.

On the Engine Ice issue, there's a big debate on it. What I'm told from

local guys is that Engine Ice runs cooler because it will not absorb the heat from the engine as well. Some experiments showed that the coolant temp was about 25 degrees cooler, but the actual internal engine temp was 25 degrees hotter. On the other hand, if you've used it and it has proven to work, that's good information. I may try it. Regardless, I may check on the fluidynes radiators and I would appreciate any comments from people who have made the change.

Thanks for taking the time to respond.


The 05' is definately a better fork. I think the 03' is 46mm and the 05' is either 48mm or 50mm (my 04' is definately 48mm).

The '04 and later are 48mm. The '05 was the first twin chamber KYB (AOSS). The '06/7 is the new speed sensitive twin chamber (SSS)

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