yz426f maintenance ?'s

[f618911]

I just purchased a 2002 yz426f. I have never owned a 4 stroke. Was just wandering if I could get some of your expert opinions on what kind of oil to use and how often it needs to be changed. Any other maintenance suggestions would be appreciated. Starting pointers would help too! THANKS

[642MX]

Here is how I do it.

Oil change and clean the oil filter every ride. I use Shell Rotella 15W40.

Clean and oil the air filter every ride. I use gas, Maxima FFT, and a UNI filter.

Check valve clearances every 4th ride.

Replace rings once a year.

Replace valve springs once a year.

Replace cam chain once a year.

BTW, welcome to TT.

[grayracer513]

There are almost as many different recommendations as to what oil to use as there are TT members. My choice is Amsoil MCF, but Rotella is good, too, as is Mobil 1 MX4T, and a good long list of others. A label showing compliance with JASO MA is an assurance that the oil will work with your wet clutch, At least, it should NOT show API EC II. Otherwise, changing oil frequently is more important than choosing it wisely.

If you follow the maintenance schedule laid out by 642, your bike may live longer than you do. It's very unlikely that you'll be anywhere near needing rings on an annual basis. Otherwise, he gives good advice. Valve springs are dirt cheap, especially compared to the trouble they could cause if they were to break, and since the crank sprocket is cut directly on the axle, it's wise not to let the cam chain go too long, either.

[642MX]

There are almost as many different recommendations as to what oil to use as there are TT members. My choice is Amsoil MCF, but Rotella is good, too, as is Mobil 1 MX4T, and a good long list of others. A label showing compliance with JASO MA is an assurance that the oil will work with your wet clutch, At least, it should NOT show API EC II. Otherwise, changing oil frequently is more important than choosing it wisely.

If you follow the maintenance schedule laid out by 642, your bike may live longer than you do. It's very unlikely that you'll be anywhere near needing rings on an annual basis. Otherwise, he gives good advice. Valve springs are dirt cheap, especially compared to the trouble they could cause if they were to break, and since the crank sprocket is cut directly on the axle, it's wise not to let the cam chain go too long, either.

I check my rings before I replace them and the edges are always worn a little bit. The ring end gap is fine, but the rounding of the edge leads me to believe that they aren't sealing perfectly. I don't have an hour meter, but I do ride almost every weekend. I would guess maybe 75 hours a year.

Gray, what would you guess the average life span of a piston ring set is? And do you think a 13.5:1 piston makes any difference?

[grayracer513]

So you only ride an average of 1.5 hours a day? Could be, I guess.

The average life of a ring set is something I couldn't even guess at. Too many variables.. One of them is the level of performance you need from the engine.. If you're in a competeitve situation where power is at a premium, Super Moto, for instance, than your schedule may not even be frequent enough. OTOH, my '03 has never had the top off it, and still runs hard.

Something to look out for is the fit of the rings in the piston. A lot of people fail to consider this, but rings that are too loose in their grooves will twist more than they should and the rings and cylinder will wear faster because of it.

[yz450vet]

I recently just bought a 2003 YZ450. It has not been heavily used and starts and runs well. After reading a bit on maintenance I am following a basic plan of changing the oil and cleaning the air filter every 10 to 15 hrs or about every two to three weeks. The bike has never had the valve clearances checked. Should I do this and what signs do I need to look for to indicate valve problems?

[jbrooks26]

I recently just bought a 2003 YZ450. It has not been heavily used and starts and runs well. After reading a bit on maintenance I am following a basic plan of changing the oil and cleaning the air filter every 10 to 15 hrs or about every two to three weeks. The bike has never had the valve clearances checked. Should I do this and what signs do I need to look for to indicate valve problems?

Yes, check your valve clearances. As for signs of valve wear, all you are looking for right now is the clearance to be within tollerance. If you have a recurring problem with the valves tightening up then that is the sign of valve wear. You will want to start a periodical maintenence schedule and include the valves in it, I would recommend every six months at a minimum depending on how much you ride. Hope this helps,

Josh

[grayracer513]

Check your valves once now, to see where they are, and again after 3-4 rides to make sure they are not closing up quickly from the hard coating being worn through. After that, once each 2-3 months should be often enough.

How often you clean the air filter will depend on where you ride. We have to do ours at least every second ride because of the dust. Not only does a dirty filter slow you down, but a dirty filter doesn't filter. I don't think the 10-15 hour plan is going to work if you ride in the company of other bikes.

I change my oil every ten hours or less (I go by 3 ride days, each including as much as 3.5 hours of ride time to as little as 1 hour) with a clean filter each time.

As for oil, there may actually be a best oil, but nobody here can agree on what it is. In general, synthetics have several advantages over dino oils. Motorcycle specific oils generally (not always) have higher levels of important anti-wear compounds and other advantages. There are several good automotive and commercial grade oils that many TT members have used for a long time with good results though, too.

One issue is compatibility with wet clutches. Oils that carry the JASO MA grade have been specifically certified as wet clutch motorcycle engine oils. This does not mean that oils not having this rating won't work; oils intended for the automobile market normally are simply not tested for compliance with the JASO standard. Oils with the API Energy Conserving II have the potential to cause clutch problems, and should be avoided unless you know someone who uses a particular ECII oil successfully.

Many Commercial ("C") grade oils are better choices than most automotive oils because the oil and its additive package are generally more suited to motorcycles, even though they may not match up exactly to JASO MA.

Another issue is shear stability. The most commonly additives that allow multigrade engine oils to hold their viscosity at high temperatures are physically fragile, and the gears in your transmission tend to tear them up so that a 10w-40 turns into a 9w-20, and sometimes surprisingly fast. This is why frequent oil changes are important. Some general guidelines are that synthetic are usually better in this regard than mineral oils, and oils with a narrower viscosity range have fewer such additives, and so are less susceptible to viscosity sheardown due to their destruction. That means that a 15w-40 would generally be tougher than a 5w-40, for example. You should also be aware that there are Viscosity Index Improvers which are capable of holding up much better, and these are used in blending multi-grade gear oils. Some of the better JASO MA motorcycle oils are using these in place of the VII's used in common engine oils to further resist shear down.

Some known good ones are:

Amsoil Synthetic Motorcycle Oil (Product ID MCF or MCV) (THE best, IMO)

Mobil 1 MX4T & V-Twin (MX4T is now called Racing 4T)

Golden Spectro 4 synthetic blend

Mobil 1 Extended Performance 15w-50 Gold Cap (?)

[yz450vet]

I appreciate the words of wisdom and plan to increase my oil change frequency and air filter cleaning. I will also check the valve clearance this weekend. I read through the valve clearance material referenced through this site and it seems fairly straightforward. I like working on my bikes but consider myself very much an amateur mechanic (I use this last word lightly). Any tips from you guys on how to check the valve clearances? Do I really need to take the carb off as per some sites?

[King_Air]

I appreciate the words of wisdom and plan to increase my oil change frequency and air filter cleaning. I will also check the valve clearance this weekend. I read through the valve clearance material referenced through this site and it seems fairly straightforward. I like working on my bikes but consider myself very much an amateur mechanic (I use this last word lightly). Any tips from you guys on how to check the valve clearances? Do I really need to take the carb off as per some sites?

It is not necessary to remove the carb. I have never removed mine to check the valves.

[grayracer513]

It is not necessary to remove the carb. I have never removed mine to check the valves.

In fact, the only thing you have to remove is the tank and the cam cover.

[642MX]

In fact, the only thing you have to remove is the tank and the cam cover.

And the top engine mount....

[FLjoyride]

And the top engine mount....

I didn't have to remove the engine mount..

[jbrooks26]

I didn't have to remove the engine mount..

You won't have to remove the upper engine mount if you have an aluminum frame. The steel frame engine mount must be removed to get the cam cover off. Just to clear this up a little.

Josh

[FLjoyride]

I've got a steel frame, 04 450 and no need to remove the engine mount. It may be different on the 426.

[jbrooks26]

OK, very well could be. Mine is an 02 426. I stand corrected.