Author Topic: 1975 Supersport, performance cafe  (Read 120050 times)

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Offline tweakin

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Re: Hot Street 1975 CB750F
« Reply #150 on: August 11, 2010, 05:59:02 PM »
After seeing this one in person I can't wait to see it completed.  Quality work all the way and I know it is going to scream.

Offline lordmoonpie

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Re: Hot Street 1975 CB750F
« Reply #151 on: August 14, 2010, 11:39:08 AM »
Hey David, in that last pic, it's difficult to tell whether the outer exhaust pipe runs inside or outside of the frame rail. Which one is it?
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Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #152 on: August 14, 2010, 12:29:43 PM »
Hey David, in that last pic, it's difficult to tell whether the outer exhaust pipe runs inside or outside of the frame rail. Which one is it?

Inside.  Why?
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 #153 on: August 14, 2010, 01:08:31 PM »
Why are you on the computer?  Shouldn't you be running that thing on the dyno? lol.

Hope it all turns out the way it should.
Hey David, in that last pic, it's difficult to tell whether the outer exhaust pipe runs inside or outside of the frame rail. Which one is it?

Inside.  Why?

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #154 on: August 14, 2010, 05:41:43 PM »
Why are you on the computer?  Shouldn't you be running that thing on the dyno? lol.

Hope it all turns out the way it should.

Best laid plans of mice and men.

Found the lowest price on a Dyna2000, but I'm paying for it now.  One full week since it was paid for, including expedited shipping, I have no tracking number nor any indication that it is in fact en route. (Traveler will of course chime in and say he told me to order the ignition earlier...)

The shift lever, clutch cable, throttle cable, oil lines are all done.  The only obstacle between me and the dyno is ignition, wires and coils.

Checking over the Norton today, and out riding tomorrow it.  I guess dyno'ing the 750 will happen when it happens...

 
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 #155 on: August 14, 2010, 06:31:34 PM »
Sh*t happens David,but I was looking forward to the results.  I am still waiting on my strator but had the 400 and Harley out yesterday.  Have to enjoy the hot weather while it is here.  Good luck getting the 2000.
« Last Edit: August 15, 2010, 05:16:41 AM by tweakin »

Offline bluesmoke69

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Re: Hot Street 1975 CB750F
« Reply #156 on: August 14, 2010, 09:40:25 PM »
Great build Dave. I am starting to make changes to my 1976 CB750F so some of the stuff your doing will help me out. Now all I have to do is get a second job!! LMAO

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #157 on: August 15, 2010, 04:05:05 PM »
Great build Dave. I am starting to make changes to my 1976 CB750F so some of the stuff your doing will help me out. Now all I have to do is get a second job!! LMAO

Welcome Bluesmoke.  It's all about sharing and learning here. Happy to add to the knowledge-base (if that's the case).
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 #158 on: August 21, 2010, 04:47:36 PM »
Not like we wouldn't have expected it to, but it runs.





We didn't put it on the dyno, but varied the rev's until it was up to operating temp and shut it down.  I'll change the oil and filter and adjust the valves once it's cooled overnight. Oddly, cylinder 1 was cutting out intermittently. I'm sure once I balance the carbs, set the mixture and strobe the timing it'll be fine.

It sounds ferocious, and revs very quickly and cleanly.
« Last Edit: August 22, 2012, 06:28:42 PM 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 MRieck

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Re: Hot Street 1975 CB750F
« Reply #159 on: August 21, 2010, 07:54:39 PM »
Nice. ;)
Owner of the "Million Dollar CB"

Offline bluesmoke69

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Re: Hot Street 1975 CB750F
« Reply #160 on: August 21, 2010, 09:47:02 PM »
Looking great!!

Offline lordmoonpie

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Re: Hot Street 1975 CB750F
« Reply #161 on: August 22, 2010, 03:01:36 AM »
Hey David, in that last pic, it's difficult to tell whether the outer exhaust pipe runs inside or outside of the frame rail. Which one is it?

Inside.  Why?
Photo made it look like it was outside to me, clearly just the angle of the photo or my squiffy eyes :D
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1951 Ducati 50cc Cucciolo
1981 Yamaha XV750 SE

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #162 on: August 22, 2010, 11:46:37 AM »
Now that I have more than a few seconds to post an update... a few other details:

It's incredibly loud! At 8k, people in the garage couldn't even yell over the volume of the bike. I may need to figure out a baffle system.  Yes, I admit I was warned.

Plugs were white and header pipes 2, 3, and 4 were glowing within a few minutes, leading me to think the needles could stand to be raised.  But, the bike wasn't under load, so I won't make any changes until we're using the exhaust gas analyzer and the dyno.

Rings seated beautifully.  Not a hint of smoke in the exhaust.  I only put a small amount of oil on the piston skirts and start-up with dry bores - like wiped down with carb-cleaner dry. It's always worked for me.

The Dyna2000 was a piece of cake to set up, including adjusting the static timing for each pair of cylinders.

Next step, tuning and break in on the dyno.  I'm pretty confident that we'll have a few full-power pulls under our belts on Tuesday night. I promise we'll have video for the voyeurs among us.

After that, we'll get the brakes, rudimentary wiring harness, sidestand, seat, and fuel-tank together - and it'll be ready for road-testing to check for handling, braking and control location. Following road-testing, we'll build the full wiring harness, relocate controls as necessary, complete fabrication, tear it down and send it off for powder and paint. (Sounds simple when put that way, doesn't it?) Best guess at completion is November.



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 #163 on: August 23, 2010, 08:27:41 AM »
Just got some pictures from Frank, aka 754, of the engine mounts he's making for me.  Wow! is about all I have to say.



Yep, not much more to say than that.  ;D
« Last Edit: August 22, 2012, 06:30:32 PM 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 MasterChief750

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Re: Hot Street 1975 CB750F
« Reply #164 on: August 23, 2010, 10:46:05 AM »
wow is right
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 MRieck

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Re: Hot Street 1975 CB750F
« Reply #165 on: August 23, 2010, 07:03:56 PM »
Just got some pictures from Frank, aka 754, of the engine mounts he's making for me.  Wow! is about all I have to say.



Yep, not much more to say than that.  ;D
Very nice work Frank. Are you open to doing more (say.....just one)? ;)
  Mike
Owner of the "Million Dollar CB"

Offline 754

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Re: Hot Street 1975 CB750F
« Reply #166 on: August 24, 2010, 08:28:14 AM »
Mike I will try to run more, not sure of timeframe.

 The big nount is for F model, the oil lines make designinging the mount trickier than it looks. These were undrilled, and have oversize studs, they have to be fitted to the engine.

 The chrome fastener seen in the pic is a chromed ALLEN NUT. Grade 8 fastener, approx .350 thread length (3/8 x 24), with a 12 point end.. fits standard allen wrench. I have not seen these in metric yet, not a common fastener, but needs less clearance around it, than nut & socket.                           754
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Lost quite a few CB 750's along the way

Offline bruisedlee

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Re: Hot Street 1975 CB750F
« Reply #167 on: August 24, 2010, 10:45:00 AM »
great build! are you guys a shop in the seattle area? very epic build.

Offline MRieck

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Re: Hot Street 1975 CB750F
« Reply #168 on: August 24, 2010, 11:01:16 AM »
Mike I will try to run more, not sure of timeframe.

 The big nount is for F model, the oil lines make designinging the mount trickier than it looks. These were undrilled, and have oversize studs, they have to be fitted to the engine.

 The chrome fastener seen in the pic is a chromed ALLEN NUT. Grade 8 fastener, approx .350 thread length (3/8 x 24), with a 12 point end.. fits standard allen wrench. I have not seen these in metric yet, not a common fastener, but needs less clearance around it, than nut & socket.                           754
My bike is an F (1975) Frank. I can see where that upper rear right side mount would be tricky. It does look nice.
« Last Edit: August 24, 2010, 04:12:36 PM by MRieck »
Owner of the "Million Dollar CB"

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #169 on: August 24, 2010, 01:49:17 PM »
great build! are you guys a shop in the seattle area? very epic build.

Welcome.  While I don't work at a shop in Seattle, I am doing most of the work at Twinline Motorcycles in Seattle. With the exception of Frank's parts, and Simon's exhaust, pretty much all of the fabrication has been done by Twinline staff. Inspection, cleaning, assembly, part sourcing, polishing and funds provided by yours truly.
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 #170 on: August 25, 2010, 05:34:28 AM »
its coming along very well


i have an F too....those mounts would be nice for my build....

Offline smpls70

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Re: Hot Street 1975 CB750F
« Reply #171 on: August 25, 2010, 07:38:02 PM »
Hey Doc, just came across your build , very, very impressive  8). I'll just have to watch this one till my hand heals up, well done !!
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Offline tweakin

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Re: Hot Street 1975 CB750F
« Reply #172 on: August 26, 2010, 05:55:11 AM »
So were is the tune video?

Offline Doctor_D

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Re: Hot Street 1975 CB750F
« Reply #173 on: August 26, 2010, 06:20:48 AM »
So were is the tune video?

Trust me, I want to run it in too.  Seems I have to tear the clutch apart and figure out why it's slipping so badly first though. Not sure what's wrong, but I did have to use a number of parts from other motors to complete the build.

Long story short, it needs to wait until after Isle of Vashon. And, yes, I'll try to hook up with you and Mike Robinson this weekend.
Take care,
David
___________________________________________
1975 CB 750F - Project page: http://forums.sohc4.net/index.php?topic=66026.msg725479#msg725479
1978 CX500
1971 Norton Commando

Offline voxonda

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Re: Hot Street 1975 CB750F
« Reply #174 on: August 26, 2010, 06:53:52 AM »
Just got some pictures from Frank, aka 754, of the engine mounts he's making for me.  Wow! is about all I have to say.



Yep, not much more to say than that.  ;D

Nice job by 754, well done.

Cheers, Rob
« Last Edit: August 26, 2010, 11:19:27 PM by voxonda »
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