interesting read from another site

[mxduner]

I Thought some of ya would find this article interesting.I like the ktm tuning features with the ignition and pv springs.

http://twostrokemotocross.com/2009/01/250s-unlimited-have-four-strokes-closed-the-gap/

[rigger]

I like that write up. That is what I have always talked about. Put same motor cc together and see what happens. Then you talk about the cost of up keep of a modern 4-stroke compared to any year of a two stroke and there is no way that you can convince me that a modern 4-stroke is better. Not saying that they are bad, I just like the two better.

[rustyATV]

http://c4.ac-images.myspacecdn.com/images02/65/l_678a93739fbb4d7aa6708064032b360f.jpg

http://c2.ac-images.myspacecdn.com/images02/74/l_e56aa8a9712847ff8ef8b45cede3e3d9.jpg

[jcs003]

funnel some damn money into two strokes and see what happens.

[C-LEIGH RACING]

:p :D :D Well now, Rusty & Mr Wilkins.
Whos idea was it painting up the sign.
Neil

[rustyATV]

I think it was originally mine when we first went to Loretta's back in '07. This year Jeff had all the stuff ready to go when I came up, but I kicked it up a notch with the air horns. Next year I'm considering a chain saw.

[All250R]

Cool site. This had a few interesting sentences in it too: http://twostrokemotocross.com/2009/06/open-letter-from-an-unhappy-mx-fan/

[matt14c]

That was a long letter! Was that ever really published or put into a magazine or just on the net? I dont believe the ama or any of the companies are switching funds just for the extra money they make which makes it a benefit im sure but it wasnt and isnt the only reason. The main is the tree huggers and enviromentalists that hate the two strokes for there smoke. Everything is changing look at all the four stroke sleds, weedwhips, blowers, snowblowers, etc etc... Everything that once was a two is now becoming four stroke. I was pretty big into sleds a few years back and things have changed big time with them. I just got my first 2 stroke quad a couple weeks ago so im just started with them and have always had the thumpers and I can say from a quad standpoint the maintance costs are far more expensive on the new motors (450's) than say even like the 400ex motors and definitly more than like the 300ex/250x motors. As far as the clubs closing I think its the economy in general, everything is struggling and well hobbies and toys are not a neccesity. Food on the table will always come before entry fees or parts for toys!

[250Renvy]

The most interesting part about it is that Yamaha was the first to start converting to 4-strokes - the reason was NOT because of environmentalists (not sure where everyone gets that). It was directly from a full page article in a magazine or their website which stated they wanted to mirror their R&D from other racing worlds and bring them into the recreational world so they could share R&D/technologies with (at the time) their cylcle and GP1 sports.

Honda then followed suit and so did all the other companies - in anticipation of more profits I'm sure and making people buy new machines. Honda had acknowledged the superior power output of the 2-stroke when they started releasing the 4-strokes.

The funny thing is that even though Yamaha started this whole 4-stroke revolution they are the only ones still producing a 2-stroke dirt bike.

In the second article about the guy ranting about the AMA - it's kinda funny because it seems to be a directly opposite reflection of the past of ATV racing. Back in the day the only people that could race were wealthy privateers, now it seems anybody can race just by going to a dealer and buying a quad (race ready) The big difference is that a Quad you can buy and race for a season and sell at the end of the year but all motor problems will be covered by a 12 month warranty despite how much they will blow up.
Bikes however have NO warranty whatsoever, so you could take it home and blow it up the next day and there is no coverage.

I still hope/wish for the day when BRP or KTM will put one of their modern 2-stroke motors in a quad.

[mxduner]

side note, yamaha is the only (outta 4) manufacturers to only carry 4 stroke snowmobiles. it is strange they are starting that in that industry but not the 2 wheel side... even the 4 wheel side, aka banshee and blaster.

[All250R]

Originally posted by 250Renvy
The most interesting part about it is that Yamaha was the first to start converting to 4-strokes - the reason was NOT because of environmentalists (not sure where everyone gets that). It was directly from a full page article in a magazine or their website which stated they wanted to mirror their R&D from other racing worlds and bring them into the recreational world so they could share R&D/technologies with (at the time) their cylcle and GP1 sports.


This quote from world.honda.com (2006) might help. You can also search the web for EPA pollution benchmarks for manufacturers to meet. One milestone passed in 2006 and was the last year a 2stroke ATV could be sold. The environmental issue is a major drive behind offroad engineering challenges, just like it was for streetbikes before, and automobiles before that. The cost is passed on to the consumer each time and since this isn't the first vehicle type to undergo these pollution standards changes, the manufacturers I'm sure have learned how best to profit from it, but that part is me speculating. Here is a quote from Honda - note the dates, of course:

"To achieve the cleaner emissions and higher fuel economy targets it announced for motorcycles in 1999, Honda began as early as 1997 to take measures to discontinue the use of 2-stroke engines by the end of fiscal 2002. These simply structured 2-stroke engines had been adopted mainly in small motorcycles because of their superior output. Our goal was to replace them with more environment-friendly 4-stroke engine technology."

2007 EPA quote (http://www.epa.gov/otaq/regs/nonroad/marinesi-equipld/a1998a-f.pdf):
We adopted exhaust and evaporative
emission standards for recreational
vehicles in our November 8, 2002 final
rule (67FR68242). These standards
apply to all-terrain vehicles, off-
highway motorcycles, and
snowmobiles.8These exhaust emission
standards will be fully phased in
starting with the 2007 model year. The
evaporative emission standards apply
starting with the 2008 model year.
Recreational vehicles will soon be
subject to permeation requirements that
are very similar to the requirements
proposed in this rulemaking. We have
also learned more about controlling
running losses and diffusion emissions
that may eventually lead us to propose
comparable standards for recreational
vehicles. We expect to revisit these
questions in the context of a rulemaking
to modify the duty cycle for all-terrain
vehicles, as described below.
Considering these new requirements for
recreational vehicles in this later
rulemaking would give us additional
time to collect information to better
understand the feasibility, costs, and
benefits of applying these requirements
to recreational vehicles.
The following sections describe the
state of technology and regulatory
requirements for the different types of
recreational vehicles.
(a) All-Terrain Vehicles

The regulations for all-terrain vehicles
(ATV) specify testing based on a
chassis-based transient procedure.
However, on an interim basis, we are
permitting manufacturers the option to
use a steady-state engine-based
procedure to allow manufacturers an
opportunity to develop the field
operating data needed to determine if
ATV operation is dominantly steady
state or transient in nature and to
develop an appropriate emission test
cycle from that information. The
emissions test procedure and duty cycle
are critical to getting the degree of
emission control expected from these
engines. We are continuing to work
toward a resolution of this test cycle
development initiative in a separate
action. The anticipated changes to the
test cycle raise new questions we will
need to work through before we are
prepared to change the existing
regulation and perhaps pursue new
emission control requirements. In
particular, we will need to further
explore the extent to which the new
duty cycle represents in-use operation
and whether engine or chassis testing is
more appropriate in simulating in-use
operation for accurate emission
characterization and measurements. We
believe it is appropriate to consider
more stringent exhaust emission
standards for these engines after we
have had the opportunity to address the
emission test cycle issue and to thus
establish a long-term testing protocols
and related requirements.

[All250R]

A while back a couple of us I think fantasized about starting a different racing organization, one that had open classes and strict displacement rules. If that rule were held tight, no one would show up to those events with a 4stroke for much longer. This would just be history repeating itself following what happened in GP racing when yamaha (I believe) developed a 250cc 2stroke that forced honda to convert to 2stroke to compete for the 250cc title.

The writer who is ranting pretty heavily... has a point I think in that the rules being bent favors the selling company's agenda at the expense of the 2stroke's reputation and marketability. I guess we'll just have to see what pans out.

[250R-Dee]

CRM250AR (Japan only) is an ECM controlled PV 2-stroke that burns cleaner than all of the 450 4-strokes on the market.

[All250R]

http://www.epa.gov/otaq/recveh.htm

[250Renvy]

Originally posted by 250R-Dee
CRM250AR (Japan only) is an ECM controlled PV 2-stroke that burns cleaner than all of the 450 4-strokes on the market.


More info please.


If you've ever seen the evinrude commercial for their outboards, they boast direct injection 2-strokes that are more fuel efficient and less pollution than any 4-stroke.

[All250R]

Service Honda recognizes the demand. Best looking CR in several years too I think personally...
http://www.servicehonda.com/250afx.html

[mxduner]

Originally posted by 250Renvy
More info please.


If you've ever seen the evinrude commercial for their outboards, they boast direct injection 2-strokes that are more fuel efficient and less pollution than any 4-stroke. heres a good read (http://www.snowgoer.com/output.cfm?id=1836523)