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JYD

I Need Monster 426 HP, Like Rediculous...

40 posts in this topic

im looking for a good 60 whp from my 02 426, suggestions? stories? please dont tell me to buy a 450, because the 4 speed is not an option.

thanks!

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A yz444 with 13.5:1CR piston will make close to 52HP. Check out Dirtrider.net and do a search on yz444.

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Thats a lot of power from a 426, as far as I know that wouldn't even be possible without going to something like nitrous or a turbo, neither of which I believe has been made into a kit for a 426.

Didn't they only make something like 38 hp stock? You might be able to get 55 with a big bore kit and lighter, high comp pistons. But I don't think 60 horsepower is even possible on these bikes.

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Tryce Welch got 60hp out of his YZ450... :thumbsup:

He might have even gotten 61hp out of it, I can't remember.

It is possible "with these motors"

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easily done!

port the head, 5 angle valve job, upgrade the cams, go bigger on the carb, bigger bore. Should not be hard.

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See my add in the "Bikes For Sale" section: YZF 426 with 459cc Engine. I'm sure it's exactly what you need! :thumbsup:

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See my add in the "Bikes For Sale" section: YZF 426 with 459cc Engine. I'm sure it's exactly what you need! :thumbsup:

well i dont need a whole bike really, want to trade motors...plus cash?

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I will if your engine is good, I would recommend exchanging engines with the carbs. Is yours totaly stock Yamaha?

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what HP does it make YZDad?

JYD...after you hot rod it, change the clutch, upgrade the chassis, fix 4th gear etc etc wouldn't your rather get a whole new bike??? Just a thought.

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what HP does it make YZDad?

JYD...after you hot rod it, change the clutch, upgrade the chassis, fix 4th gear etc etc wouldn't your rather get a whole new bike??? Just a thought.

whats wrong with my chassis and my clutch? i dont think there is anything wrong with my marchesini wheels, penske shock, and ohlins forks.

is the 5th gear ratio in a 426 the same as 4th gear in a 450?

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Typically engine builders will go through then entire engine when hopping them up. The bike "may" loose reliability as you push the limits. You should expect failure and plan ahead to avoid it.

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From another JYD Post:

"Quote:

Arm chair diagnosis:

Worst case,

Shift drum, 1 shift fork, 2 gears, 250$ +300 labor

well it does stay in gear at least, just jumps around. "

This is the stuff I am referring to.

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how much would raising compression affect the reliabilty of a stock engine? :thumbsup:

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From another JYD Post:

"Quote:

Arm chair diagnosis:

Worst case,

Shift drum, 1 shift fork, 2 gears, 250$ +300 labor

well it does stay in gear at least, just jumps around. "

This is the stuff I am referring to.

i didnt post that, someone else threw that out there. like i said, whats wrong with my chassis? i just need more power, not a new bike.

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Have not had it on the dyno (yet) I can do it though and really am going to, just need to make some time.I do know that my Son is usually first to turn one. It does not lack for power. And, is someone insinuating that there could be transmission issues with your exchange engine? The only way I'm taking in a trade will be that I recieve and install the exchange engine and check it out first. Then I'll immediately send out my engine (I guarantee mine to be excellent and I will dyno it too )

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If you are not too far from Flint, I would be happy to put it on my pump. PM me for contact info.

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