YZ426F/YZF450 questions

Because the 426 head won't fit the 450 cylinder.

As to why they put a 450 cylinder on it, I have no idea. I could not possibly guess the motivation for some of the bizarre concoctions some quad riders cob together.

So whats the difference between the 426 and 450 cylinder?

and the 426 head and 450 head?

I think there should be a cross compability chart of some sort for these motors. I think that would help alot of people out.

I thought the 450 head had bolts on the left side and the 426 has studs. Right? Your head has studs meaning it would be a 426 head, so maybe the whole thing is a 426?

*EDIT* Oh nevermind:bonk: I just looked at an 03 450 and it has studs too like the 426. So at least 1 year of the 450 has them.

I just checked, and there are studs on the left side when your sitting on the bike.

I looked at some different pics of 426's and 450's, and they ALL have studs on the left side. I remember my YFZ quad being the same.

No not "ALL" of them do. I know for a fact that the new ones probably 08-09 at least have bolts and not studs. Maybe the 03-05 had studs but I am pretty sure that 06+ had bolts. But anyway I am not really helping you with your questions, so I'll stop blabbing

The difference is that the 426 has a pair of studs, one each on the front and rear center of the gasket flange, that clamp to the cylinder. The 400, 426, and 1st generation 450 have the studs at the cam chain tower. The Gen 2 450 has bolts at that location.

The difference is that the 426 has a pair of studs, one each on the front and rear center of the gasket flange, that clamp to the cylinder. The 400, 426, and 1st generation 450 have the studs at the cam chain tower. The Gen 2 450 has bolts at that location.

So no doubt I have a..

426 bottom end

450 head

450 cylinder

I'm assuming the only difference between the YZF bike and YFZ quad is the exhaust cam?

Thanks for everything so far its helped ALOT

Also, What gaskets should I buy? I'm assuming the head gasket would be 450 since thats what those items are, but what about the base gasket? Would that be 426 or 450? I'm assuming 450 would work since it has a 450 cylinder but I figured id ask.

I'm assuming the only difference between the YZF bike and YFZ quad is the exhaust cam?

Both cams and the carb
Also, What gaskets should I buy?
I think you're on your own with this one. Mix and match time.

Hey post up a picture of your quad. I like 250Rs and would like to see your hybrid.

The questions about the engine were OK here. Pictures or discussions of quads need to move over to http://www.atvtalk.com/forum/

Gray last question, for now. Do you know if its a 450 dirtbike or quad head? I'd assume dirtbike.

Do you know if its a 450 dirtbike or quad head?
Nope. They were the same, anyway.

ok cool. Head is at a local guy right now, expecting a call soon for a price quote if he can save it.

Thanks so much for all your help.

Local guy said head is junk. Said he cant save it, port job was shitty, and the intake cam is garbage. looks like a need a new one.

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