Author Topic: 1975 Supersport, performance cafe  (Read 119934 times)

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Offline wannabridin

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    • 1976 CB750K, under construction:
Re: Hot Street 1975 CB750F
« Reply #200 on: October 25, 2010, 09:51:44 AM »
Bad phone photo, but vacuum ports for carb synch installed today. 1/8" barb / 1/8" npt.  Drilled a 7/16" hole in frozen carb boots, then threaded them in with a little clear rtv. Almost too easy.



Carbs were rejetted, 125 mains, 240 main air.  Needles were in the 2nd groove when I opened them up (bad on me for not checking), raised to clip position 5.  Did a proper bench synch, so it should idle.

I'll strobe the timing Wednesday night and give it another flogging on the dyno.  If the power still falls off at 8k, then I have to assume the cam is advanced.

this is ok to do??  how much more accurate is this than using the carb port?  also, how well can this be done on soft boots?
1976 CB750K, currently under construction:
http://forums.sohc4.net/index.php?topic=64468.0

-And if you don't do it this year, you'll be one year older when you do...

Offline 754

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Re: Hot Street 1975 CB750F
« Reply #201 on: October 25, 2010, 07:25:10 PM »
 They do make some 1/16 pipe fittings, often used on Nitrous setups.... anyway.. Just thinking smaller may look ok..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Hot Street 1975 CB750F
« Reply #202 on: October 25, 2010, 10:18:09 PM »
Dave ain't here man  (where's that from?)

Cheech and Chong

Very good, now here's yer pizza and here's your pepparoni.  ;D
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #203 on: February 11, 2011, 08:14:56 PM »
Okie dokie, mega update on the way.

Wrapped up the mock-up and dyno-tuning this fall.


Nice power numbers, but short of expectations.  78 rwhp, 52 ft/lbs torque with a nice broad torque curve.  Really had to fatten things up to get there too.  138 mains, YY7 needles, etc.


Not quite enough power, so I have a 125-75 cam on the way.

Tore the motor down after the runs to make sure all was well.  Glad I did as there were a few issues.  Three studs were loose and the head gasket was weeping.  I should have chased the stud threads in the cases.  Because I didn't, I got false torque readings.  Lesson learned.

Brazed and dressed the weld on the bike to get ready for powder coating.

 



Relocated the sidestand to clear the 4 into 4 pipes.



Frame back from powdercoating.  Metalflake silver with a coat of clear over the top.



Got a "roller" back together today.  Waiting on Frank to finish a few engine-mount bits and Mike Rieck to send on a camshaft...



Tank, seat, oil-tank, and fork brace are out at paint and due back any day now.  The tank will be an exact replica of the stock sunrise flake orange that came with the bike when it was new in 1975. Same color on the seat-pan and cowl, oil tank, and fork brace.  Antique white and black pin-striping with also pay homage to the original artwork.
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline jaguar

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Re: Hot Street 1975 CB750F
« Reply #204 on: February 11, 2011, 09:28:38 PM »
nice HP numbers so far

frame looks really nice
« Last Edit: February 11, 2011, 09:36:43 PM by jaguar »

Offline MRieck

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Re: Hot Street 1975 CB750F
« Reply #205 on: February 12, 2011, 05:30:52 AM »
 Nice work Dave. Your cam arrived yesterday. No more 125-75 billets left a Megacycle now......I got the last 2. ;D 138's....that is a lot of fuel especially with the YY7 needle.
« Last Edit: February 12, 2011, 05:39:17 AM by MRieck »
Owner of the "Million Dollar CB"

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #206 on: February 12, 2011, 08:32:41 AM »
138's....that is a lot of fuel especially with the YY7 needle.

Yep, it sure is.

I wouldn't have believed it either, except that the plug chops and the power numbers backed it up.  It wasn't until 132's that the plugs even had any color on them.
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #207 on: February 18, 2011, 04:50:09 PM »
It was a good day here at the ranch as parts came back from paint.

Flake Sunrise Orange - the first 9 coats are on.  Off to my pinstriper next, then back for 3 coats of clear.







Final product will look like the original (below), except the "Honda" will be hand lettered and not a badge.  Antique white and black pinstripes will carry over the seat cowl as well.



Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline smpls70

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Re: Hot Street 1975 CB750F
« Reply #208 on: February 18, 2011, 07:52:18 PM »
dude !
ROTHNOTHAGAR !

Offline new750f

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Re: Hot Street 1975 CB750F
« Reply #209 on: February 19, 2011, 06:57:45 AM »
nice... where do you get paint from?

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #210 on: February 19, 2011, 07:23:09 AM »
Thanks folks.

The paint is House of Kolor. Here's the process-found this on the web last summer.

Product Required:

1 pint (pt) BC-02 silver base
1 ounce MF-2 mini flake (1 oz will do test panels, tank, and side covers)
1 pt UK-8 tangerine candy
1 pt UC-01 clear coat
1 pt KU-100 hardener
2 Quarts medium reducer
Tech sheets for above

Instructions:

1- Reduce BC-02 two parts base to one part reducer, apply two full coats of BC-02 silver or until full hiding
2- Reduce BC-02 at a ratio of one part paint to one part reducer.
3- Add one gram of mini flake to every 10 grams of reduced BC-02.)
4- Apply two or three coats of mini flake and BC-02 mixture to complete panel.
5- Allow recommended recoat time, usually 30 minutes.
6- Mix and apply two coats of UC-01 clear coat.
7- Allow clear coat to fully cure.
8- Lightly block sand clear to level flake alignment with 600 wet or 800p wet.
9- Apply 4 medium wet coats of the UK-08 tangerine candy onto panel allowing each coat to flash.  NOTE: Always make test spray out panels when spraying candy for matching.
10- Always check for correct match between coat of candy.
11- Allow candy to flash for one hour.
-Add logos and pinstriping-
12- Apply two coats of UC-01 clear coat onto panel.
13- Allow to fully cure.
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline tweakin

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Re: Hot Street 1975 CB750F
« Reply #211 on: February 19, 2011, 07:57:54 AM »
Paint looks great David! 

Offline jaguar

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Re: Hot Street 1975 CB750F
« Reply #212 on: February 19, 2011, 08:11:50 AM »
love the color

Offline fastbroshi

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Re: Hot Street 1975 CB750F
« Reply #213 on: February 19, 2011, 08:51:00 AM »
+1, so much better than all the metallic grays that are so popular right now. 
Just call me Timmaaaaay!!!

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #214 on: February 19, 2011, 08:56:44 AM »
Thanks for the compliments.

Still hard to believe the before and after. There were lots of small dents and imperfections on the tank, and now it's straight as an arrow.





Should get to the wiring harness mostly together today.  If we can get the engine back in on Wednesday (waiting on the cam and last of my engine mount bolts), I'll install the tin-work and be able to get a good photo.  Need to get everything together for the pinstriper anyway.

Until then, here's a pic of the rear-master and pegs.  Cheap, aftermarket GSXR600 folders, keyed into the brackets so they won't rotate. Master cylinder is a Nissin 12mm also from the GSXR.




Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline MasterChief750

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Re: Hot Street 1975 CB750F
« Reply #215 on: February 21, 2011, 06:29:03 AM »
omg i love the paint
1978 CB750 K - Project Red Headed Step Child
1976 CB750 K - Drag Bike
Some things i know, others i dont.
I AM THE STIG
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he said i can be STIG3 tho

Offline scroggins5000

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Re: Hot Street 1975 CB750F
« Reply #216 on: February 22, 2011, 04:16:02 PM »
Great looking build! Subscribed.

Offline cobrajunkie

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Re: Hot Street 1975 CB750F
« Reply #217 on: February 22, 2011, 04:56:41 PM »
Thanks for the compliments.

Still hard to believe the before and after. There were lots of small dents and imperfections on the tank, and now it's straight as an arrow.





Should get to the wiring harness mostly together today.  If we can get the engine back in on Wednesday (waiting on the cam and last of my engine mount bolts), I'll install the tin-work and be able to get a good photo.  Need to get everything together for the pinstriper anyway.

Until then, here's a pic of the rear-master and pegs.  Cheap, aftermarket GSXR600 folders, keyed into the brackets so they won't rotate. Master cylinder is a Nissin 12mm also from the GSXR.






Nice looking tank. Question... the tabs that held the Honda emblem on the tank,  did you bang them below flush then fill the void?


Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #218 on: February 22, 2011, 05:12:40 PM »
Thanks all. For the interested, new photos will be up tomorrow evening.

Cobrajunkie: Yes, the edges of the depression were tapped down slightly with the pointy end of the sheet-metal hammer, then the depression was filled. At some time in the bike's past, the spot welded decal hardware was removed making the repair more difficult than it was worth - and I wasn't partial to the plastic letters anyway.
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline brandEn

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Re: Hot Street 1975 CB750F
« Reply #219 on: February 22, 2011, 06:14:52 PM »
Love the orange!

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #220 on: February 24, 2011, 07:11:16 AM »
Was hoping to meet with my pinstriper last night, but the mere threat of snow shut down Seattle.  As a kid who grew up in New England, this drives me bat#$%*.

Anyhow, cam arrived yesterday.  Got to degreeing it. Cam card for the 125-75 calls for intake opening, 0.040 lift at the valve, at 26deg BTDC and closes at 56deg BBDC.  I'll want to go over this one more time before buttoning up the top end as it's not quite perfect.  When the intake opening reads correctly, the intake closes at 50deg and not the advertised 56.



Since I didn't finish up the motor, I thought I'd put the tinware on the frame to see how it was going to look.  Gotta say that I'm pretty damn happy.



« Last Edit: February 24, 2011, 07:30:23 AM by Doctor_D »
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline tweakin

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Re: Hot Street 1975 CB750F
« Reply #221 on: February 24, 2011, 07:46:31 AM »
Looks outstanding David.  It is so crazy how snow freaks people out here.  "Snow Watch 2011" ;D

Offline wannabridin

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    • 1976 CB750K, under construction:
Re: Hot Street 1975 CB750F
« Reply #222 on: February 24, 2011, 09:18:02 AM »
David,

Did you paint your frame?  Looks fantastic!!
1976 CB750K, currently under construction:
http://forums.sohc4.net/index.php?topic=64468.0

-And if you don't do it this year, you'll be one year older when you do...

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #223 on: February 24, 2011, 01:12:39 PM »
Did you paint your frame?  Looks fantastic!!

It was powdercoated.  Metalflake silver with a coat of clear over the top.
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline jaguar

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Re: Hot Street 1975 CB750F
« Reply #224 on: February 24, 2011, 08:44:50 PM »
the frame and tins look great together