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Yammy 125 4-stroke 17,000 rpm
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Posted by: Dirk Diggler---------------------

I was walking through the newsagent the other day, when I saw on the cover of a Americian mag that Yamaha is developing a 125 four stroke engine capable of reving to an amazing 17,000 RPM!!!

I didn't get a chance to read the article as the missus dragged me out. Has anyone heard anything about this? What are they developing it for? The 250f runs against the 125 smokers, would it run against the 80's?

Or are they just developing it to prove there dominence as the leading engine developer and use some knowledge gained in their other motors?

17,000 RPM Faarrrk!!!

Posted by: ACS---------------------

It was a Dirt Bike magazine and had an article about a motor Powroll built for racing in the States. Check out http://www.powroll.com for the info on it. They race a 4 stroke class up to 150cc with Yamaha TTR125's and Honda XR100's. I dont know if the motor actually worked properly. There was some info on here a while ago about its race debut.

Posted by: DualSportr---------------------

Yup, it's working.

We've currently got it torn down to fix a timing chain problem (timing chain creating it's own clearances in the cases), and also install a new, stronger rod (no problems yet with the old one, just better safe than sorry).

In hindsight, we should have just used the tranny from the CR80 and cast our own cases (we've done it before) - it would have been easier than all the mods the CR cases required!

It has been a really fun project. We'll be showing up at various mini Pro races this year and next with it, so if you want to see it in action, better get a ticket for Langtown or White Brothers/BBR Nationals!

Also, Dirt Rider will probably be doing a story on it here soon - we just need to co-ordinate with them to do the photos and let them thrash it a bit.

Unfortunately, with the lag time for the magazines, it'll probably be 5 or 6 months before it shows up on the news stands!

Posted by: Rich Rohrich---------------------

There is PLENTY of room on DRN for a HUGE story about the engine, plus no messy lead times here. Just say the word and people will be lining up to read about a project this cool.

Posted by: KawieKX125---------------------

I just read the online article and it sounds awesome! I am totally amazed at the machine work required and how well it came out. How does it run? Does it sound sweet? Is it all top, bottom, or a good mix of power?

Posted by: DualSportr---------------------

Rich,

We'd love to have you (or someone from DRN) come and play with it. We'd be happy to let you review it, not only because of the quicker response time, but I belive higher quality rider/writers available from the DRN staff

The bike is fun to ride, but definitely a thoroughbred. For anyone who hasn't ridden the Pro-class TTR's or XR's we've built (in tandem with BBR) over the years, these little bikes pack a surprising punch.

The bike makes a little more hp than an XR250 (and more than a stock WR250). This may not sound too exciting, but when you pair it with much less weight and a small frame and wheel combo, it creates a bike that's not that easy to handle for the average rider.

Anyway, just the fact that you're riding something that only a few people in the world will ever throw a leg over is pretty cool.

BTW, for editors, we put the stock plastic back on - the Carbon Fiber stuff is a little fragile when it gets dragged in the dirt.

Fall is the best time to visit Central Oregon. Powroll's 20,000 sq ft. facility is only minutes away from the airport, when can we pick you up?

Posted by: Rich Rohrich---------------------

Quote:

Originally posted by DualSportr
Fall is the best time to visit Central Oregon. Powroll's 20,000 sq ft. facility is only minutes away from the airport, when can we pick you up?

I'll see what kind of time I can squeeze out and we'll talk

In the meantime if you want to put something together for the DRN faithful feel free.

Posted by: Dirk Diggler---------------------

Gee Rich, if you score a ride of one of these things you will owe me. Just think, some guy on the other side of the world gets a quick look of this engine on the cover of a magazine and you end up being able to ride it.

You lucky mongral!!

Oh yeah, I sign the papers for my new 2002 KTM 520 this afternoon. But can't pick it up until Tuesday. Bugger!!!

Posted by: DualSportr---------------------

Quote:

In the meantime if you want to put something together for the DRN faithful feel free.

When the bike's back together next week I'll be posting new action pics - much better than what we've got online now.

If anyone has any specific questions, or would like photos of a specific area, post 'em here and I'll keep it in mind while shooting next week.

I'm still buzzing after spending a day (after rain yesterday, need I mention perfect trail conditions!) on our WR 260 stroker bike. Man, that thing is fun! It beats the YZF in drag races every time, but still has more pull off the bottom. Way cool.

Tomorrow we get in two of the ----- okay Rich and other quadrophobics ---- don't read this!!! YZF 426 (with Powroll 440 stroker engines) $15,000 race quads. I'm sorry, but it'll be a kick to ride!

I love my job!

Posted by: sfc crash---------------------

wow!..all i can say is this board/site is incredible. i was searching for info on the new yamas and came across this site.wow...i feel like such a..well moron when i see people who do and know post this kinda stuff....thanks.

Posted by: Vic---------------------

Hey, PJ, any chance that you could post a dyno chart from that little screamer?

Posted by: DualSportr---------------------

Sure Vic,

When we get a few good runs on it, I'll get the info up on our website.

We've been delicate with the beast, and although we broke it in on the dyno, haven't done any real runs with it yet (it's really kinda hard on the machine, ya know?).

Also, the peak numbers from our testing will be much lower than if the bike were run on a dynojet dyno. The hydraulic dyno puts a load on the engine that's more consistent with what happens when someone is riding the bike. We consider it more "realistic".

I don't know when they plan on strapping the poor little thing to the treadmill, but I'll keep you all informed!

Posted by: Vic---------------------

Thanks.

Posted by: ACS---------------------

I hope all that work isnt going to be wasted. My contact in Japan says that the possibility of a YZ125F is really strong and it will most likely be a mini big wheel rather than a full size bike. The domestic market is very keen as they love the big wheel minis due to their size. Lot ride the big wheel TTR and XR powered CR's and YZ's but with stock engines. Thing is that it most likely will not be a 150 due to their class restrictions and FIM standards. Cant understand the FIM stuff though as it will be a mini not a full size bike unless the FIM controls mini sizes in Europe. It will be intresting here in Australia too as the MX organisers have difficulity with understanding 4 strokes and classes to run them in.

Posted by: DualSportr---------------------

Quote:

I hope all that work isnt going to be wasted.

It won't be wasted. After we're done playing with it, there are a few OEM's that are standing in line to buy it - one of which has tuning forks for their logo.

I know Yamie has looked into the 125F idea. Many rumors flying on this one (most of which seem to have been started by people in the Yamie camp).

Before anything is done though, they'll need AMA to change the 80cc class rule. No use producing a racer that doesn't fit a class.

Posted by: ACS---------------------

Depends where in the world you are>

Over here there is already classes that exist, Japan does as well and the FIM changes in Europe allow them I'm sure.

Posted by: DualSportr---------------------

Quote:

Depends where in the world you are

I thought the motocycle industry's beginning, middle and end were all located somewhere in California??

Other countries have bikes? Wow! Someone should really tell the OEM's about this!

Posted by: ACS---------------------

Yep, there is different places on planet earth.

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Yammy 125 4-stroke 17,000 rpm

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