65 HP out of a yzf400?


38 replies to this topic
  • slyfox83c

Posted June 21, 2011 - 02:33 AM

#1

I've got a 99 YZ400FL1 and wanting to get more poneys. Is there a way and what nods could I do to get another 15 hp out of this bike?
I'm a big guy and I want to be able to out run my buddys 450!!

  • sid_125_04

Posted June 21, 2011 - 03:01 AM

#2

I figure anything is possible depends on how deep your pockets are? And a lot of wrench time....

  • eskymanrod

Posted June 21, 2011 - 03:10 AM

#3

by a huski and be done with it

  • DMauro

Posted June 21, 2011 - 04:05 AM

#4

thats a tall order and will cost you if even possable! first would be a big bore big as posable. then cams, porting, high comp piston,pipe and race gas. i wouls say at least $3000 , then on a bike that old the bottom end might not hold up long. just buy a new bike and practice more!!!!!

  • R.D.

Posted June 21, 2011 - 04:08 AM

#5

For a one time dragrace you could spray it.

  • RiderX

Posted June 21, 2011 - 05:37 AM

#6

What kind of riding do you do with this bike?

  • grayracer513

Posted June 21, 2011 - 06:40 AM

#7

I've got a 99 YZ400FL1 and wanting to get more poneys. Is there a way and what nods could I do to get another 15 hp out of this bike?
I'm a big guy and I want to be able to out run my buddys 450!!


Your buddy's 450 doesn't have anywhere near 65 hp, either, and no, realistically, it can't be done with any sort of normal mods. So far, the best highly modified dirt track 450's will produce close to that level of power, but a stock YZ450, even with an aftermarket pipe, ranges between 48-52 HP. Then there's the weight thing.

  • SuperSix-Two

Posted June 21, 2011 - 07:27 PM

#8

Your buddy's 450 doesn't have anywhere near 65 hp, either, and no, realistically, it can't be done with any sort of normal mods. So far, the best highly modified dirt track 450's will produce close to that level of power, but a stock YZ450, even with an aftermarket pipe, ranges between 48-52 HP. Then there's the weight thing.


Whats a stock Yz400 rated for, anyway?

  • RiderX

Posted June 21, 2011 - 07:46 PM

#9

Around 42, which happens to be the answer to the meaning of life.

  • slyfox83c

Posted June 22, 2011 - 12:08 AM

#10

The issue is im 6' 7" and 290 pounds. He's 6' and about 200 pounds.
im planning on going through the motor this winter and while its apart I would like to hop it up a little bit. I've been a racer for 20+ years and there is no such thing as to much power. If I went with stage 2 cams and bored it, ported and polished the head I wonder about how many HP that would give me? I trail ride this bike and would like to have more bottom end to it.
or would I start running into head gasket issues like I had with my fzr1000!
Has anyone else hopped one up like this? Or would you recomed it and did you have any other issues other that a taller roost and a very light front end?

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  • RiderX

Posted June 22, 2011 - 05:58 AM

#11

Even for a 290lb guy there's definitely a such thing as too much power. That doesn't mean you won't benefit from a bit more out of your 400, depending on the terrain, but 65hp in the woods? :lol::ride: I would start with a big bore, cams, and a pipe. Make sure the cams you buy are focused on low end power, like the stage 1 Hotcams. With the big bore get a piston that will bump the compression up as much as possible without having to use race gas (unless you're ok with the cost and hassle). If you still don't feel like you have enough power then you can send out your head. You can easily spend <$500 on head work. IMO all this $$ might be better spent on a newer bike though.

  • grayracer513

Posted June 22, 2011 - 07:01 AM

#12

Whats a stock Yz400 rated for, anyway?

About 44

If I went with stage 2 cams and bored it, ported and polished the head I wonder about how many HP that would give me? I trail ride this bike and would like to have more bottom end to it.

You would first kill most of the low end power you now have, and in the process spend enough money to have bought a good used 450 in the first place.

The cure for your problem may be an XR650R.

  • slyfox83c

Posted June 22, 2011 - 11:34 PM

#13

I priced a new bike the other day and I can do a ton of mods for$8500!!!
this 400 is like new so I wouldn't be blowing money on a bike that's wore out.
I bought this bike off a older guy that didn't hardly ride it.

For now im thinking about dropping the front sprocket down to a 13 and go up 2 or 4 on the rear. That should help a bunch for the time being. I never top end this bike anyway. 3 or 4th gear is about the fastest I ever get it!

  • slyfox83c

Posted June 22, 2011 - 11:53 PM

#14

If im about 42 hp now. 50 shouldn't be too hard to get? I know race cars better than bike motors! If it was a chevy it would be a no brained!

  • DMauro

Posted June 23, 2011 - 03:31 AM

#15

you really arent making much sence . $8500 is full reatial. you can find brand new 2011 for $6600 around here. droping the front one is like adding 2 1/2 to the back so why would you do both to un up the same! then you never top out the bike? or 3 or 4 gear is as fast as you go, there lies the answer. top it out and shift and you might stay up with your friends.

  • R.D.

Posted June 23, 2011 - 03:45 AM

#16

I've always thought the same way as Dmauro. If you arent running WFO a lot and using what you got, why do you need more?

  • slyfox83c

Posted June 23, 2011 - 04:02 AM

#17

The issue isnt that im not WOT!!! There isnt enough room on the trails we ride to get it that fast!!! I hit 5th gear one time and i just about couldnt get it slowed down for the corner!!!

This bike is fast but im just looking for more acceleration out of the hole and for hill climbs and in rocky terrain!!! Its hard to ride some of the hills and climbing over rocks and dodge trees in 4th or 5th gear.. Some have tried and they have gotten air cared out of the woods.. And a few didnt make it at all...

First gear is pretty tall on this bike.. Like over 20mph. 2nd gear idoling is like 28! Im a speed freak but i know better than to try some things!! I would like to be able to pull the front end at will even when im running 40 down trails!!! There are always trees down and other obsticals that we are running into!!!!
Thats why im back to the more power!!!

I would love to have a new XR650 but that isnt in the budget in the next year or so!!!! a few hundred is possible!
Thanks for the feed back.
:thumbsup: :ride:

  • DMauro

Posted June 23, 2011 - 04:51 AM

#18

ok heres what you do. go one bigger on the back sproket and put in hot cams stage 1 cams and a youh pipe. all bolt ons and would not sacrafice relability at all. you will only get a few HP but it would pull the way you want.:thumbsup:

  • grayracer513

Posted June 23, 2011 - 07:27 AM

#19

I priced a new bike the other day and I can do a ton of mods for$8500!!!

Who said new? Used '06/'07 models are all over the place for $2500

If im about 42 hp now. 50 shouldn't be too hard to get? I know race cars better than bike motors! If it was a chevy it would be a no brained!

If it was a Chevy you'd have 10 times the displacement to work with, and probably an engine producing a third as much power per liter to start with. At 42, your bike is already making the same kind of power as a 350 Chevy that pumps out 600 HP. Getting to 50 would be a 20% increase. Please don't try to say it would be a no-brainer to take a 600 horse mouse motor to 720. You're missing the scale of the situation, it seems to me.

  • RiderX

Posted June 23, 2011 - 11:56 AM

#20

Not to mention you're trying to solve your problem the wrong way. If you're riding this bike in tight woods with some hill climbs, and rarely get out of the first 3 gears you would be better served with a little more torque at lower rpm, and gearing changes, not a 65hp death trap. Pick some simple mods that will achieve this, like suggested above-cams that are focused on low end power, a pipe, and a bigger rear OR smaller front sprocket. If you're only working with a few hundred $$ I would suggest a sprocket and a pipe to start with. Also make sure the bike is tuned properly. A lot of power can be lost with improper jetting.





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