Messages

61

General Two Stroke Talk / Re: Maico-the final answer

« on: May 03, 2010, 05:26:11 PM »

There's a lot of talk about "modern" and "innovation" and "all new" and "redesigned" surrounding these new 4t race engines. If you really look at it though, it's amazing how little these modern, innovative, all new, and redesigned machines have over a bike like the old Maico 490.

Hell, yamaha's biggest 4t innovation in the last few years has been to flip the cylinder around. Big flipping whoop? 90% marketing, 10% actual improvement. And even that is probably being overly generous.

62

General Two Stroke Talk / Re: Just want to be clear on the cc vs cc in ProAMA.

« on: May 02, 2010, 04:13:15 PM »

Johasus!  I think that guy needs a medal, because pulling a 450F with a sub-200cc bike is the equivalent of winning a Formula One race in a stock Corvette.  It just shouldn't be possible, but according to this story, it apparently is.  Then again, I have heard of small bikes doing amazing things.  Like the 100 Green Streak that was having carb trouble at the Sidewinders flat track back in the day (long before my time.)  The rider was messing around with the carb as he cruised easily around the track, then he did something right, and the thing cuts a slide, pulls the front tire into the air and takes off like a bat out of hell.  A 100cc bike, with a full-grown man onboard in the 1960s!  Green Streaks had some sort of mystical voodoo about them, I swear.

I heart Green Streaks. I must have one.


I like where this thread is going. We know we can't get equal displacement. It would pretty much be instant death for the 4t, and there's no way in hell the big four will let it happen. Just a little more is all we need to really be competitive.

63

Technical / Re: boyesen powerwing / Scary fast power now

« on: May 02, 2010, 08:01:25 AM »

what modifications can you do to your carb besides jetting?

RB Designs, for example, bores the carb to a larger diameter, installs the divider plate, reworks the idle circuit, and a few other little bits. Together with these mods, the "wing" can make an improvement in throttle response at openings below 1/2 throttle, and the overall larger diameter increases performance at larger throttle openings.

64

Technical / Re: Putting a silencer on

« on: May 02, 2010, 07:58:26 AM »

NO! If you put that silencer on and fire it up, the bike is sure to explode in a furious black mushroom cloud, taking out at least 3 blocks of your neighborhood!!

Kidding. You likely will not have to re-jet. Bolt it on and go. Don't expect much change going to the shorty though, other than an annoying increase in noise output.

65

General Two Stroke Talk / Re: Lack of interest

« on: April 20, 2010, 11:46:30 AM »

I've said it before, but I think all references to two- and four-strokes should be wiped from the books.  Just say that the displacement must be thus-and-so, and leave it to the developers to come up with the better mousetrap, regardless of how many strokes they want to use.

That'd be great news for the 2 stroke, but I think we all know it would be sudden death for the 4t, so I figure it's not likely any time soon. Hopefully I'm wrong!

66

General Two Stroke Talk / Re: TM 125MX First Race

« on: April 14, 2010, 06:17:49 PM »

Wow, that's outstanding! Massive props to everyone involved!

67

Technical / Re: boyesen powerwing / Scary fast power now

« on: April 14, 2010, 09:49:38 AM »

Without additional modifications to the carb to take advantage of this mod, it would be akin to installing one of those turbine fans in the intake of your car. To say, not worth a darn.

68

Technical / Re: break in procedures

« on: April 12, 2010, 03:59:02 AM »

Yup, just re-clarifying for the reading impaired. 

great post, btw!

69

Technical / Re: break in procedures

« on: April 10, 2010, 05:39:01 AM »

Chokey's method up there is for breaking in a forged piston. If you're just seating rings, see the 2nd post in this thread.

70

General Two Stroke Talk / Re: Handicapping and Four-Strokes...

« on: April 08, 2010, 04:09:28 PM »

Totally stealing that one for my avatar, lol. thanks!

71

Technical / Re: ATF as gearbox oil?

« on: April 06, 2010, 12:54:24 PM »

Been using ATF Type F for years, love it.

72

General Two Stroke Talk / Re: KTM reveals race-ready electric motorcycle, production within 2 years

« on: March 27, 2010, 07:56:03 AM »

I don't like how they make peak power at any RPM.  It would feel awesome on low-end, but then you'd get ready for the top-end and it would feel, well, flat.  The problem four-strokes have is that their power curve is a smooth, shallow arc.  Two-strokes are more fun because their dyno chart looks like the Matterhorn, so you've got to shift and clutch and stay in the meat of the power.  There's challenge.  With an electric bike, it would feel like going back to the one-speed 50cc with the centrifugal clutch.  "Okay son, twist this to go fast, push on this to go slow."  There's no challenge; nothing to do.  When you take away the powerband and transmission, you get to the point where you might as well have training wheels.

That said, if someone could program it to feel like a two-stroke in power delivery, and figure out that the transmission is not just a means to an end but an end in itself, I'd be satisfied for a playbike.

Yeah, the transmission would no longer be necessary. Perhaps a 2 speed gearbox. I can relate to your concerns about the power delivery being TOO linear. I've ridden 250f's and was bored to tears. I wanted my 2 stroke back ASAP. I've played around a lot with programmable ESC's and brushless DC motors though, and there are many options for power curves, regenerative engine braking, etc. It's an interesting field with a lot of possibilities. Like I said though, it has a long way to go before it could be considered as a replacement in my mind. I'm just excited about the technology is all..

73

General Two Stroke Talk / Re: KTM reveals race-ready electric motorcycle, production within 2 years

« on: March 26, 2010, 08:35:04 AM »

The only things I have against electric bikes are the power delivery and lack of noise.

Can you elaborate on that power delivery part? I'm curious. In my experience with brushless ac/dc motors the power delivery quite frankly puts IC engines to shame. The power/torque curve can be programmed in infinite ways depending upon the ESC in use and it's capabilities. There is no "peak" for HP or Torque in these electric motors, so the motor is producing it's peak power regardless of RPM. What's not to like?

I think electric has a long way to go before it could even be considered as a replacement for the IC engine in dirt bikes, but for me it's nice to see someone taking the first steps!!

74

General Two Stroke Talk / Re: So excited!

« on: March 14, 2010, 07:23:31 AM »

Excellent!

While I don't frequent the MX tracks as I'm solely an off-road rider, I will be competing in some HS races this year on a KDX. Over the last couple years I have noticed more and more 2 strokes at all our riding spots, mostly KTM 200/300's. The sounds you hear on the mountain have changed dramatically, especially during this last season. It's really good to see!

75

General Two Stroke Talk / Re: Bajaj & KTM ?

« on: February 13, 2010, 05:32:10 AM »

Oh... check out www.ktm.com , something interesting is going on.