Go Back   EcoModder Forum > EcoModding > Motorcycles / Scooters
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 06-17-2011, 09:18 AM   #11 (permalink)
Master EcoModder
 
euromodder's Avatar
 
Join Date: Jul 2010
Location: Belgium
Posts: 4,665

GasDwarf - '13 Volkswagen up! EcoFuel CNG
Thanks: 176
Thanked 639 Times in 506 Posts
Old 2 strokers are extremely pollutant.
A 4 stroker - say a 250cc - will be a lot better on the environment.

__________________
GasDwarf's fuel consumption :
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 06-17-2011, 01:56 PM   #12 (permalink)
Master EcoModder
 
Join Date: May 2009
Location: New Jersey
Posts: 389

2003 Ninja EX250 - '03 Kawasaki Ninja EX250
90 day: 78.57 mpg (US)

Saturn - '99 Saturn SL1 Base
90 day: 47.27 mpg (US)
Thanks: 25
Thanked 58 Times in 37 Posts
Modern marine 2-strokes are direct injected and are much more efficient than carbureted or fuel injected 2-strokes. In a direct injected 2-stroke, fuel is injected right down at the piston as it closes the exhaust port, so very minimal (if any) fuel escapes out the exhaust. Also, in a direct injected 2-stroke, oil is not mixed with the gas, as it is contained and circulated much like a 4-stroke car engine.

Power curves can be tailored for a broader torque range by using (what they call in motocross) a "Power Valve". Its basically a valve that alters the diameter of the exhaust port, which in turn changes the power characteristics of the engine at certain rpm's.
__________________
Doing my part to reduce dependence on OIL
Doing my part to reduce congestion
And enjoying it!

If you have to use your brakes, you are driving too fast!

My 101.5 MPG 2003 Kawasaki Ninja 250




Crude Oil Price Today
  Reply With Quote
Old 06-17-2011, 03:24 PM   #13 (permalink)
dcb
needs more cowbell
 
dcb's Avatar
 
Join Date: Feb 2008
Location:
Posts: 5,038

pimp mobile - '81 suzuki gs 250 t
90 day: 96.29 mpg (US)

schnitzel - '01 Volkswagen Golf TDI
90 day: 53.56 mpg (US)
Thanks: 158
Thanked 267 Times in 210 Posts
Quote:
Originally Posted by theycallmeebryan View Post
Modern marine 2-strokes are direct injected and are much more efficient than carbureted or fuel injected 2-strokes...
but in terms of this thread...
Quote:
Originally Posted by winlie88 View Post
I found a dirt bike for $500 - it's a 1980 Suzuki PE 175cc, 2 stroke engine.
__________________
WINDMILLS DO NOT WORK THAT WAY!!!
  Reply With Quote
Old 06-28-2011, 08:42 AM   #14 (permalink)
EcoModding Lurker
 
Join Date: Feb 2011
Location: Tampa FL
Posts: 49
Thanks: 2
Thanked 2 Times in 2 Posts
Two strokes vary wildy depending on the specifics of the design. Some are very crude and don't make huge power or get great mileage (but can still be huge fun), some are very fast, but still use a ton of fuel and others are very nearly on-par with current four strokes.

I have a few two stroke MX race bikes. They are astounding from a performance and reliability standpoint. They make huge power in a light package and seem essentially indestructible and if something does go rebuliding the whole engine takes no more time than a valve adjustment did on my CRF. These are liquid cooled, reed valve and exhaust valve engines with huge carbs and aggressive porting. I've never run one at constant speed on the highway and doubt I ever will. Fairly casual trail riding (which still includes lots of wheelies, powerslides etc) will get about 70 miles from a 3 gallon tank. Street use would be better I think for mpgs.

I also have a kawasaki H1 with expansion chambers. Its a 500cc air cooled piston port two stroke triple. Kawasaki really only had two design goals in mind. First, make the fastest production bike of the era and second be able to sell it for <$1k. They succeeded in both. Its crude, vibrates, uses a bunch of fuel (about 18mpg), smokes and has a narrow power band, but its still huge fun!

Generally air cooled piston port two strokes are pretty inefficient and have narrow power curves. Some manage to do pretty well though, for example Tomos mopeds are pretty efficient and not far off four strokers.
  Reply With Quote
Old 07-20-2011, 04:25 PM   #15 (permalink)
Polymorphic Modder
 
SoobieOut's Avatar
 
Join Date: Aug 2010
Location: Utah
Posts: 307

2006 DaCivic Hybrid - '06 Honda Civic Hybrid
90 day: 45.16 mpg (US)
Thanks: 188
Thanked 39 Times in 24 Posts
I rode a Yamaha Daytona Special for a few years. It was a high performance version of the RD400, 2 stroke 400cc.

The service manual recommend replacing the pistons every 2500 miles! I could replace them in about an hour, what a pain.

I remember getting about 25 MPG, and it smoked alot, even with oil injection.

I think that barring a huge leap in 2 stroke technology, going with a 4 stroke is the best bet for fuel economy.

Remember when Al Gore was going to outlaw the 2 stroke engine?
  Reply With Quote
Old 04-26-2012, 08:05 PM   #16 (permalink)
home of the odd vehicles
 
rmay635703's Avatar
 
Join Date: Jun 2008
Location: Somewhere in WI
Posts: 3,164

Silver - '10 Chevy Cobalt XFE
Thanks: 317
Thanked 603 Times in 445 Posts
What happened to the $350 envirofit envirokit?

Can these still be purchased somehow? This would be ideal for my Subaru 360.

Or did they never actually go ahead and sell out to someone?

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com