Author Topic: Bonneville Turbo CB500/550  (Read 55209 times)

0 Members and 1 Guest are viewing this topic.

Offline kayaker43

  • Hot Shot
  • ***
  • Posts: 422
Re: Bonneville Turbo CB500/550
« Reply #250 on: March 26, 2013, 02:00:23 pm »
I'm with Scottly on the pump,.. Regardless of how it may have been used, its supposed to suck fuel from the bowl and squirt it down the carb throat whenever the throttle is opened. Its supposed to be cable driven off the throttle.

Completely different than a fuel pump who's purpose is to keep the float bowl full.

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,294
  • ROCK & ROLL
Re: Bonneville Turbo CB500/550
« Reply #251 on: March 26, 2013, 02:10:55 pm »
I'm with Scottly on the pump,.. Regardless of how it may have been used, its supposed to suck fuel from the bowl and squirt it down the carb throat whenever the throttle is opened. Its supposed to be cable driven off the throttle.

Completely different than a fuel pump who's purpose is to keep the float bowl full.

I'm with Greggo, its a custom made set up to keep the bowls full due to the extra fuel used to feed the engine under boost, my old drag bike  had 2 petcocks and fuel lines to keep the fuel coming, an electric fuel pump would do the same thing...
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline kayaker43

  • Hot Shot
  • ***
  • Posts: 422
Re: Bonneville Turbo CB500/550
« Reply #252 on: March 26, 2013, 03:24:09 pm »
Makes no sense?? The squirt volume from those pumps is way too small and what on earth would have driven them by cable? It would take you 50 squirts to fill a float bowl. They were sold as cable driven accelerator pumps to improve throttle response. I remember installing these for people back in the 70's

You must be confusing them with similar fuel pumps that have much bigger diaphragms and are driven by crankcase pulses.  You typically see these on snowmobiles.

Offline Greggo

  • Somebody's
  • Old Timer
  • ******
  • Posts: 4,164
  • Helmets Save Lives. Period.
Re: Bonneville Turbo CB500/550
« Reply #253 on: March 26, 2013, 03:57:34 pm »
I'll let you guys debate it if you please, but I've spoken with the man who put the kit on his 550 in the late 70's, and modified the carb with the pump to keep the bowl full, or keep it from drying up at the least. 

Offline scottly

  • Really Old Timer ...
  • *******
  • Posts: 14,293
  • Humboldt, AZ
Re: Bonneville Turbo CB500/550
« Reply #254 on: March 26, 2013, 06:05:11 pm »
Look at this way: if you want to ensure the float bowl is full to the proper level, you would have a pump between the fuel tank and the normal carburetor input, so the float can do it's job. ;)
That is obviously an accelerator pump, and, depending on the location of the jet within the carb throat, may also act as a high-speed enrichment jet. 
Don't fix it if it ain't broke!
Helmets save brains. Always wear one and ride like everyone is trying to kill you....

Offline ivanhoew

  • Hot Shot
  • ***
  • Posts: 298
Re: Bonneville Turbo CB500/550
« Reply #255 on: March 26, 2013, 11:52:33 pm »
i created that sort of high speed enrichment  on my 400/4 turbo , with the xs650 carb , i ran a pipe from the drain on the float bowl ,and placed its end in the airstream about 2/3rds of the way up th carb inlet .using a bit of brake pipe ,and crimped the end to create a nozzle ,it was suprisingly effective.
just do it .

Offline Greggo

  • Somebody's
  • Old Timer
  • ******
  • Posts: 4,164
  • Helmets Save Lives. Period.
Re: Bonneville Turbo CB500/550
« Reply #256 on: March 27, 2013, 02:13:15 pm »
I went back to the emails exchanged when I bought the kit, and the pump attached is indeed an accelerator pump.  There was a separate pump between the tank and carb.  I'd forgotten he had ditched that pump long ago because it was too big, and just remembered there was a pump to keep the bowl full.  My apologies for the confusion Gents.  I'll need to find a good sized pump to do that job, and I will set the current one up as a Go-Fast button.

From the seller:

The fuel pump was a lost cause and I pitched it years ago it was a stewart warner thing that was too big anyway.

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,294
  • ROCK & ROLL
Re: Bonneville Turbo CB500/550
« Reply #257 on: March 27, 2013, 03:28:48 pm »
Yes, after thinking about it it could not fill the bowls, interesting set up though....
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline scottly

  • Really Old Timer ...
  • *******
  • Posts: 14,293
  • Humboldt, AZ
Re: Bonneville Turbo CB500/550
« Reply #258 on: March 27, 2013, 10:33:54 pm »
he had ditched that pump long ago because it was too big, and just remembered there was a pump to keep the bowl full.  My apologies for the confusion Gents.  I'll need to find a good sized pump to do that job,that was too big anyway.
The PO of my bike had installed a huge fuel pump, about the size of a can of beer, plus a fuel pressure regulator set to about 2-1/2 pounds. I guess he thought the Webers wouldn't work with gravity feed. ::) As long as you have an adequate flow though the petcock, you shouldn't need a pump. If you chose to run a pump, look into Facet Cube pumps; they are only about 2 1/2"x 2 1/2", and draw about 1.6 amps.
Don't fix it if it ain't broke!
Helmets save brains. Always wear one and ride like everyone is trying to kill you....

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,294
  • ROCK & ROLL
Re: Bonneville Turbo CB500/550
« Reply #259 on: March 28, 2013, 12:47:42 am »
he had ditched that pump long ago because it was too big, and just remembered there was a pump to keep the bowl full.  My apologies for the confusion Gents.  I'll need to find a good sized pump to do that job,that was too big anyway.
The PO of my bike had installed a huge fuel pump, about the size of a can of beer, plus a fuel pressure regulator set to about 2-1/2 pounds. I guess he thought the Webers wouldn't work with gravity feed. ::) As long as you have an adequate flow though the petcock, you shouldn't need a pump. If you chose to run a pump, look into Facet Cube pumps; they are only about 2 1/2"x 2 1/2", and draw about 1.6 amps.

Or run 2 petcocks.... ;)
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline Old Scrambler

  • My CB750K3 has been in 39 States & 5 Provinces
  • Old Timer
  • ******
  • Posts: 3,457
Re: Bonneville Turbo CB500/550
« Reply #260 on: March 28, 2013, 05:18:55 pm »
I drained my bowl on two separate runs at the salt flats. Who would think a little 201cc single could drain a Mikuni 29mm carb ;) ;)

The quick fix was to raise the float a tad and it worked :) :)

But the real fix is to have larger diameter holes in the brass fuel lines where the rubber fuel line attaches. The check list is.............measure the petcock flow volume with a timer.........then add the line and check again.........then add the fuel filter (if you use one) and check again............then add the carb and check the flow with the bowl removed.  Any reductions should be eliminated ;D ;D ;D
Dennis in Wisconsin
'64 Triumph Cub & '74 Honda CB750 Bonneville Salt Flats AMA Record Holder (6)
CB750 Classic Bonneville Racer thread - http://forums.sohc4.net/index.php/topic,135473.0.html
'63 CL72 Project(s)
'66 CL77 Red
'67 Triumph T100C
'73 750K3 Owned since New
'77 750F2 Cafe Project
2020 ROYAL ENFIELD Himalayan

Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,354
Re: Bonneville Turbo CB500/550
« Reply #261 on: March 28, 2013, 07:02:00 pm »
I have a dual outlet Pingle you can drive a truck through.

It'll pass gas!

Offline DustyRags

  • I'm not skilled, I'm just a
  • Hot Shot
  • ***
  • Posts: 720
  • Just try it and see what happens
Re: Bonneville Turbo CB500/550
« Reply #262 on: October 28, 2013, 09:31:53 pm »
Hey Greggo, any updates on this baby?
1976 CB550K- sold
2005 Kawasaki Vulcan 500- sold
2000 CB750 Nighthawk - sold
1975 XL350 - crashed
2004 Suzuki Vstrom 650 - sold

Offline Greggo

  • Somebody's
  • Old Timer
  • ******
  • Posts: 4,164
  • Helmets Save Lives. Period.
Re: Bonneville Turbo CB500/550
« Reply #263 on: December 19, 2015, 10:02:33 am »
It just sits, trapped in a corner...I did get a clear california title for it, but I don't have space to work on it for now.  I turn the motor over every few months, but that's about it.


Offline Stev-o

  • Ain't no
  • Really Old Timer ...
  • *******
  • Posts: 30,560
  • Central Texas
Re: Bonneville Turbo CB500/550
« Reply #264 on: December 19, 2015, 01:20:49 pm »
Doesnt seem possible that you bought that bike over 3.5 years ago....
'74 "Big Bang" Honda 750K [836].....'71 Honda 750K project.....'76 Honda 550F.....K3 Park Racer.....K5 Fiddy Dolla Special!......and a Bomber!............plus plus plus.........

Offline Greggo

  • Somebody's
  • Old Timer
  • ******
  • Posts: 4,164
  • Helmets Save Lives. Period.
Re: Bonneville Turbo CB500/550
« Reply #265 on: December 19, 2015, 01:57:46 pm »
Doesnt seem possible that you bought that bike over 3.5 years ago....

I know...I had to watch the video of it running again ;D I'll street it some day..

Offline Stev-o

  • Ain't no
  • Really Old Timer ...
  • *******
  • Posts: 30,560
  • Central Texas
Re: Bonneville Turbo CB500/550
« Reply #266 on: December 19, 2015, 03:10:00 pm »
Doesnt seem possible that you bought that bike over 3.5 years ago....
I'll street it some day..


I know you will....or it gets shipped to Texas!
'74 "Big Bang" Honda 750K [836].....'71 Honda 750K project.....'76 Honda 550F.....K3 Park Racer.....K5 Fiddy Dolla Special!......and a Bomber!............plus plus plus.........

Offline Tews19

  • I am no
  • Really Old Timer ...
  • *******
  • Posts: 6,451
Re: Bonneville Turbo CB500/550
« Reply #267 on: December 21, 2015, 08:31:22 am »
No #$%*, 3.5 years ago! Time has really gone by fast!
1969 Honda CB750... Basket case
1970 Honda CB750 survivor.

Offline Lostboy Steve

  • Old Timer
  • ******
  • Posts: 3,095
    • Lost Boy's Blog: Atomic Garage
Re: Bonneville Turbo CB500/550
« Reply #268 on: December 21, 2015, 12:31:43 pm »
Not to change the subject, but is that a g60 on that Bus? Did that project take priority?
1968 Honda Z50
1977 Honda CB550K
1982 Honda GL1100i
2005 Yamaha Raptor 50
2009 Honda FourTrax Foreman Rubicon
2013 Yamaha WR250R



For my projects/activities: http://www.atomicgarage.net

Offline Greggo

  • Somebody's
  • Old Timer
  • ******
  • Posts: 4,164
  • Helmets Save Lives. Period.