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250 horse power?

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How much horse power does a 2006/07 yz250 have? how much more can you get out of it with pipe/exhaust, port/ polish? is it very close to a 450? thanks

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The 450s are not as responsive and as light as the 250's. The 250 does good (either the same or sometimes better than a 450) on short runs like 1st through 4th gears. But as soon as you reach 5th gear the 450 does seem to pull just a tad bit harder. Not enough to make a difference in lap times on most tracks but enough to show if you are drag racing or if the start straight is really really long (havent seen one that long yet, but you know).

Stock the 250 has 47HP and weighs 211 dry...

Stock the 450 has 50HP and weighs 232 dry.

The 250 can be modified to make about 50 to 52 HP. Most of that extra HP will come from porting, head work, high compression, race fuel and good tuning.

It wont come from pipes, reeds, and other bolt on parts.

Dont invest in bolt on parts unless you are into the bling factor.

Look around, the slower the rider, the more the bling.

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Look around, the slower the rider, the more the bling.

I think its the other way around

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if your gonna go for top speed a stock yz250 will blow away a 450 but for bottom end it will take alot to get up to ther.

your joking right ? your not going too beat top-speed of a 450 ...

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Stock the 250 has 47HP and weighs 211 dry...

Stock the 450 has 50HP and weighs 232 dry...

Try,

Stock the 250 has 47HP and weighs 211.6 dry...

Stock the 450 has 50HP and weighs 220 dry... and feels lighter than that :thumbsup:

That smoke must be getting to your head :ride:

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The 250 could get as much HP as the 450, but it can NEVER get as much torque as the 450, thats the difference from a 2 and 4 stroke. :thumbsup:

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Stock the 250 has 47HP and weighs 211 dry...

Stock the 450 has 50HP and weighs 232 dry...

Try,

Stock the 250 has 47HP and weighs 211.6 dry...

Stock the 450 has 50HP and weighs 220 dry... and feels lighter than that :thumbsup:

That smoke must be getting to your head :ride:

Yes you are correct... I got the wet mixxed with dry.

With that said though, the 4 stroke does put on more weight when fluids are added because it holds more fluids.

Onward to the smoke thing...

I am not some little 15 year old in a forum net, you wouldnt talk to your dad that way would you? Would you want me to talk to your dad that way?

Learn some respect

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Yes you are correct... I got the wet mixxed with dry.

With that said though, the 4 stroke does put on more weight when fluids are added because it holds more fluids.

Onward to the smoke thing...

I am not some little 15 year old in a forum net, you wouldnt talk to your dad that way would you? Would you want me to talk to your dad that way?

Learn some respect

I'm not troutman, but i took his smoke comment to be a reference to the extra emmisions of a two smoke, not a dig at you or drug usage. I don't know, maybe i'm the one looking to far into it. :thumbsup:

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The comment about the "little 15 year old" is a bit of a generalization there buddy, some of them are pretty big nowadays.

I disagree with the theory that some bolt on items won't increase HP. With the YZ 250 your going to get bugger all HP with porting work unless you want to spend massive amounts on testing as the ports are pretty good in standard trim. As an example High comp pistons are a form of bolt on performance gear, only they are not bolted on so to speak. Pipes and reeds do make some difference to the power and its delivery which might not look too big on a dyno but to me better response/torque characteristics can help your machine hit that 47 HP or whatever you have a bit quicker.

I'm not taking this too seriously as to offend anybody just giving an opinion.

I wish I was 15 again.

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The port heights and general shapes on the YZ250 are perfect for the power delivery the engine produces. But not perfect as far as casting flaws and sometimes even slightly uneven port heights. Cases can be better matched to the cylinder. The exhaust port & intake track is where most the gain will be on the actual cylinder IMO.

When I took my YZ250 engine apart I wasnt impressed with the equalness of the port heights, seams, and casting errors. Its amazing it runs as good as it does like that, imagine if it was cleaned up to be perfect!

On most bikes I have modified, the head (with addition of good fuel) is where most of your power gains came from.

I'm not a pro on cylinder porting, I have just had enough done and even done a couple myself (which turned out ok but wasnt pretty).

There is a lot of people in this forum constantly trying out bolt on parts, reeds, and pipes. Its a common trend they go back to the stock stuff because it just doesnt get any better, anymore.

Now back in the 90s... HELL yeah we needed all the reeds, pipes, ignitions and crap we could pile on because the stock stuff was not as perfect and sometimes sucked.

And I too wish I was 15 again, I sure would do a lot of things differently.

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And I too wish I was 15 again, I sure would do a lot of things differently.

Count me in on that too. :ride: Maybe we should start a "who wishes they were 15 again" forum. :thumbsup:

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On most bikes I have modified, the head (with addition of good fuel) is where most of your power gains came from.

I'm not a pro on cylinder porting, I have just had enough done and even done a couple myself (which turned out ok but wasnt pretty). QUOTE.

Have to agree with you on the head work, I bet your shaving the head as well to up the compression, thats why you need the race gas mix. This is ok if your running laps on a track with your fuel available all the time, but not practical for the people such as myself who need to get fuel out in the sticks.

I'm no expert on the porting either but when I enquired with an expert he basically recomended that for the money spent the gains would be very minimal. Trust me he knows what he is on about.

Just for reference.

I have put a pipe, reeds and power blade in my 01 and 'am very happy with the gains. I have even gone to a 33:1 mix after reading the posts on the fuel mix ratios.

Keep up the good work

This is a very informative Forum

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I havent done anything to this engine yet. I dont know if I will either. If I did I have a friend that does this for a living that could re-chamber the head and do the porting for very little money. But to be honist, I'm happy with the bike the way it is. Although sometimes I do wonder how it would feel to have the bike breathing fire!

I t does take some mixture of race fuel to be 100% happy, but its ok.

Back when I was on 125's I had to modify every bike I owned just to have enough power.

I'm still wondering what all was done to Chad Johnsons 06 yz250 Race bike? Anyone know?

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Yeh I'm with you on the 125s, you are never going to have enough power till you step up to the 250,

Don't know what happened with that blokes 250 but my mate built the 125 engines for Brett Metcalfe last year and he still has them from yamaha sitting in his workshop. 42 HP if you can keep it within the 2000rpm band.

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I'm still wondering what all was done to Chad Johnsons 06 yz250 Race bike? Anyone know?

Chad told me he loves the V Force reed set-up. Outside of that he told me to contact junior Jackson. http://www.juniorjacksonracing.com/

Chad said Junior would build us his exact motor if we wanted it.

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Yes you are correct... I got the wet mixxed with dry.

With that said though, the 4 stroke does put on more weight when fluids are added because it holds more fluids.

Onward to the smoke thing...

I am not some little 15 year old in a forum net, you wouldnt talk to your dad that way would you? Would you want me to talk to your dad that way?

Learn some respect

Wow, a little defensive :ride: I am not 15 anymore either but I am sitting here with sore legs from the track and wishing I was 15 again, that was a very good year for me and my 1987 RM 125. I am not sure what you meant by the whole "dad" and "respect" thing, but if you are asking if I would tell my dad he was wrong and giving people with legitimate questions incorrect information, then yes I guess I would talk to my dad that way. I am sorry if the smoke comment offended you but it was just a light hearted comment and had nothing to do with having or not having respect for anyone. I love 2 strokes, especially YZ's, and get passed by them regularly, but there is a choice now and if I was trying to decide which one to get I would like to know the true weights of the bikes and I only intended to state the facts. 1000 apologies. Lighten up :thumbsup:

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