All 2st Power #'s from a dyno run?

I have check mine yesturday and i have 165 psi.

Here is the new dyno chart with the head + timing mod + new jetting.

Wow the head mods really improved it. nearly 42 hp at 6000 rpm is most impressive - about 5 hp increase on before and a TE450 . What timing was it running - standard ?
I hope you can hang on to it now!!

My timing is advanced (i will check this week-end and take some pics)
The head mod is time consuming and its better to have a good backgroup to have a good result. The old guru that have work on my head have also made some "spiral" on the dome. I think the GasGas piston make it a lot easyer.

The result on the trail is awesome, the bike cant be better and i think i will let it like that for very long. The motor come on A LOT sooner and have no flat spot from idle to the moon !

Even 165psi is low for a hi po 2 stroke motor IMO. I'm going to ask for a substantial compression increase when I have my head done. If it doesn't respond right or is too aggressive then its easily fixed on the lathe.

What did the squish measure at stock? And what was is set at now?

After seeing the numbers and hearing your input........
I need my WR head massaged stat! I had a feeling there's a lot of power to be had from the head.

For whomever was asking about measuring the squish, check this out:
http://www.rb-designs.com/squish-band-test.htm

More compression dont mare necessary more horsepower and can reduce the power on high rpm if all thing are not ajusted.

If you want more than 50 whp, port the cylinder. You can make over 60 whp on pump gas on a 300cc 2 stroke engine with 160 psi. My Honda 250R (now 330cc) make 63 whp (old engine design, no PV). On a 2 strokes, all is on the porting and timing. This bike have 160 psi.



Also, i have this baby... 610cc,over 85 whp... but no reliability blow head gasket every 2-3 ride... 240psi comp.

Absolutely agree about too much compression can kill power, but too little compression isn't optimal either. It's a fine balance of many factors and that's why everyone is not a tuner.

Me and a friend both have big bore YZ's built by the same person with the same porting specs. Only the heads differ. His blows 185# fresh and mine blows 215# fresh. They're both fast, but mine is quite a bit stronger throughout the power spread. Even running -2 timing vs. his stock timing. Not exactly scientific data, but when all other factors are equal and the motor is setup properly a higher compression motor is going to be stronger IMO. Until you hit the ceiling, but too much of anything (case volume, squish band/angle, etc...) can be bad.

I have ridden a smoker with too much compression before and it was flat. It just fell on its face right off idle and couldn't recover.

And people think 2 strokes are simple


Nice 250R!
I had an 1987 model from 1990 until 1999 when I mistakenly sold it. That was my learning grounds.... I blew that thing up so many times I could disassemble it in my sleep.

Quadzilla's weren't reliable stock, so no surprise a 70hp version blows gaskets Fun though. I just got rid of my banshee a few months ago. I loved it and had a lot of fun with it, but my elbows and wrists cant take the beating anymore. Those bikes made me a believer about 2 stroke horespower...65-70hp motors built for $1000 are dime a dozen in the dunes.



PS- thanks for doing this and posting up. Very cool!
I'm now itching bad to get my head done up.

PC
FYI , Ron did my head and when he was done he feels like it is maxed out with the stock flat top piston ( 155psi ) . If I had it to do over I would change out the piston to the domed Gas Gas one , then have the head done to match. From what he said it is still real sloppy on the squish and the head design really needs a domed piston. There isnt enough matreial in the head to machine it to a optium flat top profile. Sounds like a good winter project.

The GG piston is like $250 though. On top of the head work.
Did Ron's head work with the stock piston make a large difference?

hrc630,
the dyno chart didn't show. Can you please add the link?
I'd like to see it, especially on a non-PV motor.

Thx.

I prefer a 160 psi motor that work on pump gas and rev to the moon to a 200+ psi motor that need race fuel and sign off at high rpm...

Here is a dyno chart of my Honda 250R (330cc)

It made a difference, not Holy Shi-----, but a nice difference. So what I am saying is if I had it to do it over again I would wait until I needed to to a top end job and just do it then, I wouldn't think the pistons would be that much different money wise.

F'ng sweet thread ... I'm not sure ~7G @ 40 horses is UR average run of the mill short shift ...


I have never believed most 450s would have anything on these 300s after owning a 02 CR250 ... That thing in stock form was scary fast n 2-3-4 gears ... You gonna pin a 300? Please have UR eye balls screwed in tight!

Thanks for the charts! What pipe are you running on the 300? I put a C2 racing pipe on the 02 CR and it pushed it into another realm ... It felt like the new power band just super-ceded the previous one ....

I really like threads like this too! My bike runs really sweet now with the PWK and EEL needle in 2nd clip The best so far. I´ll try the EEM soon to see if i can get even cleaner running on very light throttle. I also ordered a Wössner GasGas piston yesterday. One thing that is good with the very long gearing i run now is that every change i do with the jetting gets very noticeable as i have "time" to really feel how it behaves in every gear. I can also humiliate my friends KTM to see the difference Maybe i can get close to 50whp. What do you guys think? I payed about 230 dollars for the forged Wössner piston with Teflon coating here in Sweden. I guess they are cheaper for you guys in US and Canada as everything else that has with bikes to do!

Johnny:sweden::sweden:

That's good to know. I bought a 450 partially for the top speed, as I ride in the desert and on dry lakes a lot. I had wanted to race it in Best of the Desert series, but have never got my act together to do that.

If the 300 smoker is the equal or better of the 450 in terms of power why does the 450 still work better at high speed? Isn't it mostly gearing? Or is it the reluctance to run a 2T at high revs for long periods of time.

Back in the 1980s the Honda 500, KTM 550 (!) and Kawasaki 500 were the tools of choice for desert racing. No one even thought a four stroke was worth bothering with. Then Honda built the elephantine 650 H2O cooler XR and won seven in a row, but, stranely Kawasaki quit factory supporting the KX-500 teams as the bike was no longer current.

I'm not sure the 4T is really better in the desert. It may be a case of self-fulfilling prophecy.

Husky should make 500cc 2t for desert and dune use.

The way I heard it wasn't quite like that. It was more like Kawasaki kicked everyone's ass in the Baja 1000 for years, then Danny Hamel died in a crash and Kawasaki pulled out leaving Honda to take over.

Yes, that sounds about right. What I was trying to say is we never got the epic battle of the KX-500 Kawasaki factory team vs. the XR-650R Honda factory team in Baja. It would have been fun to watch it play out, but maybe because of Danny's death, it never happened.

Just got my 2008 TE 250 dynod and it pulled 17.13 torque and a MAX power of 32.52 Does this sound right or WTF low?

http://www.pbase.com/jdjetting1/image/53444147

Tasky's in WA tested in 2006 and got about the same (although carbed). TC was 1 hp more.

That sound good... for a 4 strokes... remove 2 strokes and you will gain 10 more whp
(sorry, its just my Canadian humour !)

Can you post the charts to see the curve ?

Yeah I could surely post it if I was smart enough :P Im not 100% techno saavy... I also did not mension I have the power commander, custom intake and custom exhaust. NOTHING leaves my hands stock I have to mark it as mine somehow! Pissing on it would rust my sprockets