Author Topic: Getting closer...CB750A supercharged-fuel injected  (Read 19671 times)

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Offline rickmoore24

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #50 on: December 06, 2010, 11:46:47 AM »
wowzers, the work you're doing is great!
1972 CB750 K2 (Daily Runner)
1972 CB750 K2 (Sold)
1973 CB750 K3 (Hardtail 836cc)
1998 CBR F3 - R.I.P., went down on the 101 in Calabasas, Ca.
1995 EG6

Offline fmctm1sw

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #51 on: December 06, 2010, 05:02:58 PM »
Just noticing this thread.  3 words...  WTF!? (in a good way)
Quote from: 754
Dude is that a tire ? or an O-ring..??

Quote from: inkscars
This is not a pod thread
This is not a #$%* on my vacuum gauges thread
This is a help or GTFO thread.

1973 CB350F
1973 CB350G
1975 CB550K
1983 GL650I
1973 CB750K3 (http://forums.sohc4.net/index.php?topic=92888.0)
1984 Kawasaki KLT-250 (AKA 3 wheeler of death)
1994 Honda TRX300
1999 Honda TRX250

Offline Syscrush

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #52 on: December 06, 2010, 05:45:19 PM »
23tbucket, I like your updates so much I might offer to start giving $5 to the United Way every time you post one.  ;D
Life is precious: wear your f'n helmet!
There's nothing more expensive than a free bike...
FWIW, I'm not a shill for Race Tech - I've just got a thing for good suspension and the RTCE's are the most cost-effective mod for these old damping rod front ends.

Offline 23tbucket

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #53 on: December 06, 2010, 05:51:22 PM »
The intake plenum; I originally carved out some foam from a spray can. I thought I could just cover the shaped foam with the fiberglass and then use acetone to eat away the foam......Acetone dosn't eat the can sprayed foam!!!, So then I went to the hobby shop and got some plasticine...shaped it, covered the plasticine mold in fiberglass, and cleaned out the plasticine with tools, gasoline, and the wifes dishwasher!!!!

I thought about using some sort of by-pass system as 750essess mentioned. It would have been a lot less work. I could have run some tubing out from my blow-off valve, set up some kind of linkage to control some sort of sliding sleeve valve or port. It would have to be open when the throttle is closed and would close as the throttle opened. It would have taken a lot of tinkering to get things just right.

I talked to a drag racing friend......he showed me where the carbs and throttle bodies were on his dragsters.....Yep! on the intake of the superchargers................

Offline lordmember1969

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #54 on: December 20, 2010, 02:36:54 AM »
Hi:)
LOVE YOUR BUILD:) Question.. do you think i can go kick only onthe fuel injektion with the mickrosquirt.. Will it work? Or do i have to keep the starter?

Thanks

LM

1977 CB 750 SS Cafe
1977 CB 750 Basket case
1971 Mustang Grande
1928 Model A Pheathon Hot Rod
1977 Harley Custom FXE

http://forums.sohc4.net/index.php?topic=70333.0

Offline Old Scrambler

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #55 on: December 20, 2010, 05:50:01 PM »
Awesome..........I knew I should have kept that A!
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
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Offline 23tbucket

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #56 on: December 23, 2010, 05:27:16 PM »
Lordmember: I'm sure you will need the 12 volt starter motor when it comes time to first program the Microsquirt ECM. You will make many, many, many starts before you get it right. Just to have the engine start and idle on its own you need:
Required fuel set correctly......
Cranking pulse widths set correctly......
Warm-up enrichment set correctly...
After-start enrichment set correctly...
Volumetric Efficiency table close around the idle manifold pressure

Some of this stuff has to be within .5 milliseconds and in a "true" cold start condition......which means it's going to take a few days.....and a good battery!!!

Then you need to "tune" for the road......again...many, many days!!

Once you get everything set where you are happy..you may be able to kick start to your delight? They do start instanly when the fuel injection is right....and no choky needed...lol

Offline tweakin

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #57 on: December 23, 2010, 06:04:13 PM »
Amazing work! 

Offline lordmember1969

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #58 on: December 24, 2010, 02:33:34 AM »
Lordmember: I'm sure you will need the 12 volt starter motor when it comes time to first program the Microsquirt ECM. You will make many, many, many starts before you get it right. Just to have the engine start and idle on its own you need:
Required fuel set correctly......
Cranking pulse widths set correctly......
Warm-up enrichment set correctly...
After-start enrichment set correctly...
Volumetric Efficiency table close around the idle manifold pressure

Some of this stuff has to be within .5 milliseconds and in a "true" cold start condition......which means it's going to take a few days.....and a good battery!!!

Then you need to "tune" for the road......again...many, many days!!

Once you get everything set where you are happy..you may be able to kick start to your delight? They do start instanly when the fuel injection is right....and no choky needed...lol
Thank you and Merry Christmas:):)
1977 CB 750 SS Cafe
1977 CB 750 Basket case
1971 Mustang Grande
1928 Model A Pheathon Hot Rod
1977 Harley Custom FXE

http://forums.sohc4.net/index.php?topic=70333.0

Offline luhojs

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #59 on: January 09, 2011, 11:58:01 AM »
Quote
Question.. do you think i can go kick only onthe fuel injektion with the mickrosquirt.. Will it work? Or do i have to keep the starter?

I have used a MegaSquirt in the past which is essentialy the same as a microsquirt just different type of electronics. The software in both are the same.
In order for the microsquirt to "know" that you want it to squirt when you are starting the motor it reads the ignition pulses. When it determines that the number of pulses is above a certain treshhold (I don't remember exactly but I think it was 300 rpm) it wil start to squirt.
This was hardcoded at the time, so you cannot switch it off. Well you can but you have to be an assembly and C programmer.
The answer to your question is then: yes you can kickstart providing you can make it go around fast enough.

Better start training them calves !!
cb750 chopper
cb750 dragbike

Offline 750essess

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #60 on: January 12, 2011, 09:09:39 AM »
you can set the cranking rpm now in the tuning software.. I think kick start with fuel only would be possible. Ignition too, adds problems.
Orleans Cycle Repair and Restoration
76CB750F
69Z50
XR650L

Offline immortal

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #61 on: January 12, 2011, 11:43:04 AM »
Amazing project!...Keep us posted!
Sometimes...the hard thing and the right thing are the same thing!

1976 CB750F "Pegasus Bike"

http://forums.sohc4.net/index.php?topic=80492.0

Offline Tintop

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #62 on: March 28, 2011, 05:35:19 PM »
Just got directed here, now to go to page 1, and read. ;) :)
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
Sidecar Rebuild Thread

Offline Bankerdanny

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #63 on: March 29, 2011, 02:03:08 PM »
Somebody needs to introduce 23T to Brother Joeyput! Two amazingly original fabricators.
"The problem with quotes on the Internet is that you never know if they're true" - Abraham Lincoln

Current: '76 CB750F. Previous:  '75 CB550F, 2007 Yamaha Vino 125 Scooter, '75 Harley FXE Superglide, '77 GL1000, '77 CB550k, '68 Suzuki K10 80, '68 Yamaha YR2, '69 BMW R69S, '71 Honda SL175, '02 Royal Enfield Bullet 500, '89 Yamaha FJ1200

Offline Tintop

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #64 on: March 29, 2011, 04:49:42 PM »
Having read through your build 23T, the fabrication quality is amazing.  Did wonder how you were going to solve the pressurized throttle body issue.  Looking forward to more updates.
1977 CB550/4 Cafe - Speed Warrior / BOTM 03/11
1980 CB750F (project)
Whittaker GBF Vintage Racing Sidecar (XS750 power) - ITG / 151's / CMR Racing Products (SOLD)
1976 CB400 SS - stock / BOTM 04/11 (SOLD)
1973 CB750 K - basket case (SOLD)
77 CB550 Cafe build
550/750 Filter Thread
Sidecar Rebuild Thread

Offline tomsweb1

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #65 on: March 29, 2011, 05:38:29 PM »
I want to see this piece of art ripping down the road. I traditionally hate choppers, but this is gorgeous.
Present: 1978 CB750A, 1978 CB400A, 1983 Nighthawk 550, 1984 CM250C

Past: 1977 XL100, 1982 KZ1300

Offline 23tbucket

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #66 on: April 07, 2011, 12:58:05 PM »
I'm sorry, I haven't been keeping you fellows informed on my progress. After having to do all the big changes to the blower intake...I kind of was disheartened with the whole idea of starting to reprogramme the whole fueling stuff again. But the snow is melting, the geese are back, and it will be soon riding weather again. I've been tuning things for the last two weeks. I had things real, real close. The engine start-up (cranking pulse widths) on cold and hot were dead on. Once the engine goes above the cranking speed (I got mine set at 500rpm) the after start enrichment comes in along with the warm up wizard programme. This was all tuned very nice. I got the VE (Volumetric efficiency) table set real close at idle and up to 2000rpm.
Another few days of tuning and I think the bike would be ready for the open road.

Then I got another huge setback.........I was tuning the VE maps when for no reason the engine just died!!! I thought maybe I ran out of fuel....nope, pressure still at 43psi. Checked all the ignition wiring etc. Started the engine...it's running on only #1 and #4? Rechecked everthing again and restarted the engine. This time only #2 and #3 are firing...WTF? Used an ohm meter to check all the wiring...all is good...? I then took the ignition cover off....I right away could smell the unmistakable odor of burnt electronics!!! I dropped down the Power/Arc ignition stuff and found the encoder had had a meltdown.....dam, dam, dam.

That bubble's not supposed to be there!!!lol


So, now I have to wait for a replacement. I think the failure was due to trying to run four "coil-on-plugs"? However, the folks at Power/Arc had assured me their system would work with what I was trying to do. We'll see!!...Now, whether they warranty things or not...... I'm going to scrap the coil-on-plugs thing. It looked cool, but too hard to troubleshoot and change plugs. I think I had a stronger spark with the coils that came with the Power/Arc kit.

Glad I got three other bikes to ride!!!

Offline Mantree

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Re: Getting closer...CB750A supercharged-fuel injected
« Reply #67 on: December 14, 2015, 11:08:09 AM »
So I didn't see if you had to modify the spacing on the throttle bodys to make it fit the engine