Author Topic: vintage EFI for cb500/550? news to me!  (Read 3171 times)

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Offline alacrity

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I recently restored and sold a 77 cb750f, and am nearly finished with a (former basket case) cb750k5.  This is a place to share, learn and enjoy.  I am grateful to and for 99+% of this site's membership.

Offline flybox1

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Re: vintage EFI for cb500/550? news to me!
« Reply #1 on: February 19, 2015, 11:46:22 AM »
search POSA here on the forum.  quite a few threads.... ;D
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

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Offline strynboen

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Re: vintage EFI for cb500/550? news to me!
« Reply #2 on: February 19, 2015, 12:48:57 PM »
yes,, terry down under have tested them...not positive test
i kan not speak english/but trying!!
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Offline Garage_guy_chris

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Re: vintage EFI for cb500/550? news to me!
« Reply #3 on: February 19, 2015, 06:57:51 PM »
Just so you know this isn't EFI (electronic fuel injection) its some form of mechanical fuel injection. It is indeed interesting and havent seen it before and would love to learn more about it.
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Offline Don R

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Re: vintage EFI for cb500/550? news to me!
« Reply #4 on: February 19, 2015, 08:18:31 PM »
 Needs a mechanical fuel pump.
No matter how many times you paint over a shadow, it's still there.
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Offline Retro Rocket

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Re: vintage EFI for cb500/550? news to me!
« Reply #5 on: February 19, 2015, 11:09:03 PM »
If I remember right, its biggest problem was the outer 2 cylinders running lean due to the design of the manifold..
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Offline Muckinfuss

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Re: vintage EFI for cb500/550? news to me!
« Reply #6 on: February 20, 2015, 07:53:52 AM »
Unless you're opening a museum, save your money.
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Offline Rookster

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Re: vintage EFI for cb500/550? news to me!
« Reply #7 on: February 20, 2015, 08:18:23 AM »
It does not need a fuel pump and it isn't truly fuel injection.  It is more like a large carburetor without a float bowl.  It is gravity fed.  Very similar to Lake injectors.

Scott

Offline strynboen

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Re: vintage EFI for cb500/550? news to me!
« Reply #8 on: February 20, 2015, 12:29:07 PM »
 does it
have a vaccum melbran pump like a thainsaw kaburettor ??
i kan not speak english/but trying!!
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Offline jaguar

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Re: vintage EFI for cb500/550? news to me!
« Reply #9 on: February 25, 2015, 05:00:36 PM »
Mine.

Offline strynboen

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Re: vintage EFI for cb500/550? news to me!
« Reply #10 on: February 26, 2015, 06:20:33 AM »
nice alu manifold...take the POSA off..and put an nice kaburator on instead..and you have a nice setup..
i kan not speak english/but trying!!
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Offline jaguar

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Re: vintage EFI for cb500/550? news to me!
« Reply #11 on: February 26, 2015, 06:27:33 AM »
I have had single and dual Posa Set ups on CB750s before.
Interesting to say the least.

Never seen one for a 550.
Figured it is just what my chopper needed.
Probably paid to much for the novelty, but it will be fun.

But when then again maybe not.  Someone paid $150 for just a manifold
http://www.ebay.com/itm/Posa-Fuel-Manifold-Carburetors-/251736705406?pt=Motorcycles_Parts_Accessories&hash=item3a9cad497e&vxp=mtr

Offline jaguar

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Re: vintage EFI for cb500/550? news to me!
« Reply #12 on: February 26, 2015, 06:29:17 AM »

Offline strynboen

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Re: vintage EFI for cb500/550? news to me!
« Reply #13 on: February 26, 2015, 06:32:27 AM »
yes  it is  Rare :o
« Last Edit: February 26, 2015, 06:36:36 AM by strynboen »
i kan not speak english/but trying!!
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i hate all this v-w.... vords

Offline jaguar

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Re: vintage EFI for cb500/550? news to me!
« Reply #14 on: February 26, 2015, 06:40:09 AM »
Yeah, there are more then a few concessions that need to be made to deal with these.....

Offline strynboen

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Re: vintage EFI for cb500/550? news to me!
« Reply #15 on: February 26, 2015, 06:45:38 AM »
 it musthave a seperat idel kontroll..vaccum is too unstabill to regulate the fuel direkt..even the needel are turn to regulate the flow..or hov are it funktion...trhainasv have a low idel and a full speed adjusting..and not so mutch betveen..but a mc need to variabel  and pull in all rpm..its not so simpel to make work..
i kan not speak english/but trying!!
http://forums.sohc4.net/index.php?topic=60973.0
http://forums.sohc4.net/index.php?topic=144758.0
i hate all this v-w.... vords