Daiichi Kosho DK 472 engine or not??

Discussion in '2-Stroke Aircaft Engines' started by danmoser, Feb 1, 2013.

Help Support HomeBuiltAirplanes Forum by donating:

  1. Feb 1, 2013 #1

    danmoser

    danmoser

    danmoser

    Well-Known Member

    Joined:
    Feb 1, 2010
    Messages:
    630
    Likes Received:
    186
    Location:
    Sandy, Utah, USA
    I believe I have a Daiichi Kosho 472 Engine ... but I'm not sure... can anyone confirm?
    This was acquired with a lot of other parts from a friend of a friend who became too old & sick to build & fly aircraft, or even communicate with others very well... so I can't find out anything about this engine from him.
    I measured a bore of 58mm and a stroke of 47mm.. which works out to 250cc on a twin cylinder.

    According to this description:
    Daiichi Kosho Whisper - Wikipedia, the free encyclopedia
    and studying a couple of youtube videos, it appears to fit with a DK472 engine.
    Two cylinder opposed (boxer twin) 2-stroke engine with 250cc displacement.
    It's very light at only 15.2 pounds w/o exhaust, and supposedly puts out 22 hp... an impressive power-to-weight ratio, if true.
    But I can't find any detailed info. on this little gem... no manuals, specs, pilot reports, testimonials.. nuthin' !

    If it is the DK 472, it was used on the Beat and Whisper PPGs (not Whisper GT), but is now out of production.. DK totally withdrew from the paramotor business several years ago.
    Supposedly, the DK472 has a good reputation for reliability... relative to other 2-strokes.
    I was hoping to use it to motorize a SWIFT ultralight glider with direct drive or with prop speed reduction drive.
    But without knowing more about it, where to get parts, etc.. I'm reluctant to mess with it.
     

    Attached Files:

  2. Feb 1, 2013 #2

    Dana

    Dana

    Dana

    Super Moderator Staff Member

    Joined:
    Apr 4, 2007
    Messages:
    8,674
    Likes Received:
    3,051
    Location:
    CT, USA
    It might be a DK, but I'm not familiar with that engine... was out of production by the time I started flying PPG, about 15 years ago. You might try asking on a PPG list like the ppgbiglist Yahoo group, there are still some old timers there who would remember it.

    -Dana

    Why is it called tourist season if we can't shoot at them?
     
  3. Apr 18, 2013 #3

    danmoser

    danmoser

    danmoser

    Well-Known Member

    Joined:
    Feb 1, 2010
    Messages:
    630
    Likes Received:
    186
    Location:
    Sandy, Utah, USA
    I have been told by another DK-472 owner that I do indeed have the DK-472.
    He said he has been very pleased with the engine, and that these engines have a very good reputation for reliability and smooth operation.
    Add that to the extremely light weight, and this would normally be judged as GREAT NEWS.
    However, Daiichi Kosho totally abandoned all of their paramotoring products over a decade ago, including this little gem of an engine that they developed themselves.
    No spares, no support, nothing!
    I can't even find anyone that has an owners manual, let alone any source for support or spare parts.
    So I guess I'll be selling this to someone else who may need parts for it.
     
  4. Apr 18, 2013 #4

    garrywarber

    garrywarber

    garrywarber

    Well-Known Member

    Joined:
    Mar 28, 2008
    Messages:
    164
    Likes Received:
    6
    Okay then, how much you want for it? I'm still thinking on your Konig's, but this twin looks interesting...Garry
     
  5. Apr 20, 2013 #5

    danmoser

    danmoser

    danmoser

    Well-Known Member

    Joined:
    Feb 1, 2010
    Messages:
    630
    Likes Received:
    186
    Location:
    Sandy, Utah, USA
    Picture attached, along with direct drive prop.. I'd sell engine for $500 plus $50 for prop.
    I'm hoping my machinist/gearhead buddy would consider reverse engineering it .. and offering parts/support.
    It is rare to have an engine of this type & size.. the Desert Aircraft DA 170 (RC engine) is close.
    BTW, the Konig engines are both sold. IMG_20130323_180416.jpg
     
  6. Apr 21, 2013 #6

    garrywarber

    garrywarber

    garrywarber

    Well-Known Member

    Joined:
    Mar 28, 2008
    Messages:
    164
    Likes Received:
    6
    Ah, well, a little high for my way of thinking... Besides, if you have someone to do a little reverse-engineer payback that is the way to go. Just for the principle of the thing if no other reason. :) I would like to not mix "species" anyway, and I have two Limbach 275's now. Should you find one of those, or parts, please let me know.
     
  7. Apr 22, 2013 #7

    Head in the clouds

    Head in the clouds

    Head in the clouds

    Well-Known Member

    Joined:
    Mar 11, 2012
    Messages:
    1,983
    Likes Received:
    890
    Location:
    Gold Coast, East Coast of Australia
    Depending on what horsepower you need I found this 3W 275cc engine very interesting at 15lbs, 26hp and about $3000 - or this 3W 210cc engine at 11lbs, 18hp and about $2400. It looks like they'll both swing 36" props direct drive which should work well on a Swift.
     
  8. Apr 22, 2013 #8

    Xanadrone

    Xanadrone

    Xanadrone

    Well-Known Member

    Joined:
    Nov 24, 2011
    Messages:
    195
    Likes Received:
    43
    Location:
    Bucharest Romania
    Yes, german-made 3W engines are very good, but the czech MVVS brand produces equally reliable, but lighter and more powerful 2-strokers - ex: the new 175-NP - 172.8 cc, 19.8 HP/6.700 rpm, 9.5 lbs (ignition included), recommended prop 32 x 12 (direct-drive).
    MVVS 175 NP 175np1_e.jpg

    And they are cheaper too (1,570 euros=2,000 USD with european VAT or 1,700 USD without taxes) - especially here: MVVS engines
     
  9. Apr 22, 2013 #9

    garrywarber

    garrywarber

    garrywarber

    Well-Known Member

    Joined:
    Mar 28, 2008
    Messages:
    164
    Likes Received:
    6
    After reading its specifications, and if I were able to buy new, this one would be really interesting! Looks like the small boxers are becoming well-available again.Garry
     
  10. Apr 22, 2013 #10

    Xanadrone

    Xanadrone

    Xanadrone

    Well-Known Member

    Joined:
    Nov 24, 2011
    Messages:
    195
    Likes Received:
    43
    Location:
    Bucharest Romania
    Yes, 2-strokers for RC-use are becoming lighter and more powerful, but also more reliable (with Nikasil cylinder-coatings, high quality bearings – usually 3 for the crakshaft and 2 for piston/conrod -, computerized auto-advance ignitions, automatic choke-carburettors etc). The only drawbacks: the need of a battery for ignition ad absence of EFI.
    I’ll be back anyway on the engine’s dedicated topic, whilst I have enough experience in this field and maybe this could be useful to some HBA colleagues.
     
  11. Apr 22, 2013 #11

    dino

    dino

    dino

    Well-Known Member HBA Supporter

    Joined:
    Sep 18, 2007
    Messages:
    603
    Likes Received:
    86
    Location:
    florida
    They have put these type of engines (I think 3W) on the Cri-Cri. Cooling in pusher configuration may be challenging.

    Dino
     
  12. Apr 22, 2013 #12

    Xanadrone

    Xanadrone

    Xanadrone

    Well-Known Member

    Joined:
    Nov 24, 2011
    Messages:
    195
    Likes Received:
    43
    Location:
    Bucharest Romania
    That's true, two 3W-Modellmotoren (220 cc older version, approx. 20 HP each) are used successfully by a NZ-Cri-Cri.
    You can observe in the picture the counter-clockwise rotative right prop (useful solution for 1-engine stop emergency situation).

    IMG_6458.jpg
     
  13. Apr 23, 2013 #13

    Dana

    Dana

    Dana

    Super Moderator Staff Member

    Joined:
    Apr 4, 2007
    Messages:
    8,674
    Likes Received:
    3,051
    Location:
    CT, USA
    I have heard of that being a problem with the few people who have used these engines on PPGs.

    Dana

    Sometimes it is easier to beg forgiveness than get permission.
     
  14. Jul 28, 2013 #14

    danmoser

    danmoser

    danmoser

    Well-Known Member

    Joined:
    Feb 1, 2010
    Messages:
    630
    Likes Received:
    186
    Location:
    Sandy, Utah, USA
    Just sold the DK-472 engine on eBay.. actually having some regrets about it, in spite of DK's shameful withdrawal of support for their product.. I think the opposed 2 and 4 cylinder 2-strokes are a great pathway to a lightweight aviation engine.. particularly if modern improvements are added, such as EFI, programmable spark advance, and dual CDI ignition.. auto-compensating for altitude, RPM, eliminating carb ice worries, and reducing fuel consumption.. perhaps flat-2 and flat-4 aviation engine designs based on existing 2-stroke engine parts from commercial sources, such as the 14hp Radne Racket 120cc could be successful?? ..hmmmm? Imagine a 28hp 240cc opposed twin and a 56hp 480cc flat-4.. bad ass!!
     
  15. Jul 28, 2013 #15

    garrywarber

    garrywarber

    garrywarber

    Well-Known Member

    Joined:
    Mar 28, 2008
    Messages:
    164
    Likes Received:
    6
    Hi Dan,
    Check this new Canadian one out:
    Boxer 200T

    Likely you know of it already because we are in the same yahoo groups, but maybe not... :) It looks good, but as usual, spendy...
    Garry
     
  16. Jul 29, 2013 #16

    Vipor_GG

    Vipor_GG

    Vipor_GG

    Well-Known Member

    Joined:
    Jun 9, 2013
    Messages:
    850
    Likes Received:
    113
    Location:
    Cayce, SC / USA
    It looks like it could be a contender, but I'd be more interested in the 400T at the bottom of this page.:grin:
     
  17. Jul 29, 2013 #17

    garrywarber

    garrywarber

    garrywarber

    Well-Known Member

    Joined:
    Mar 28, 2008
    Messages:
    164
    Likes Received:
    6
    Great link! That entire page is interesting. Do you think "cutting edge" would apply? The boxers have an exhaust valve, which would allow supercharging... Think of your light weight four-popper supercharged. Lots of power to weight ratio, I suspect.
    Garry
     
  18. Aug 3, 2013 #18

    Vipor_GG

    Vipor_GG

    Vipor_GG

    Well-Known Member

    Joined:
    Jun 9, 2013
    Messages:
    850
    Likes Received:
    113
    Location:
    Cayce, SC / USA
    If they can keep it under 60lbs with 40 hp it would be good for ULs, if they could get it to 50 hp then it could be a candidate for lighter LSAs. This is provided they keep the cost down and it is reliable to the 500 hour TBO.
     
  19. Aug 3, 2013 #19

    clanon

    clanon

    clanon

    Well-Known Member

    Joined:
    Jun 6, 2007
    Messages:
    1,101
    Likes Received:
    217
    Walter Kaaden here , is telling me that some form of exhaust could be critical ,for each one...
     
  20. Sep 5, 2013 #20

    danmoser

    danmoser

    danmoser

    Well-Known Member

    Joined:
    Feb 1, 2010
    Messages:
    630
    Likes Received:
    186
    Location:
    Sandy, Utah, USA
    Well, I got the DK-472 returned from the guy who bought it.. apparently he couldn't get it started, so I offered him a refund.. he said the carb was clogged, and wasn't sure it was getting a spark.. well, now I don't know what to do with it.. don't really have the time to put into it

    On the issue of tuned exhaust, I do think you ought to have it for a 2-stroke.. not so much for power perfromance, but to shove some of the unburned fuel-air mixture back into the combustion chamber by the reflected pressure wave.. otherwise, it just consumes too much fuel and pollutes the air excessively.

    On the boxer 200T and 400T engines.. they do look interesting!
    However, they don't really seem to be in production..
    The guy was using crowd funding to finance the final development efforts, maybe OK, but seems like you could be risking your money on a not-for-sure deal.. ya never know!
     

Share This Page



arrow_white