Author Topic: Cobra motor disassembly and rebuild  (Read 107732 times)

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Offline BPellerine

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Re: Cobra motor disassembly and rebuild
« Reply #400 on: June 26, 2016, 03:28:36 PM »
cool cam sprocket bill!billp
1978 CB 750K ard and webers
another anfob

Offline PeWe

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Re: Cobra motor disassembly and rebuild
« Reply #401 on: June 27, 2016, 03:04:27 AM »
Yes, no need of timing cam when sprocket is fixed ;)
I saw that a check to verify correct timing was done...
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Bill/BentON Racing

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Re: Cobra motor disassembly and rebuild
« Reply #402 on: June 27, 2016, 04:40:54 AM »
Sprocket not fixed, is slotted so you can adjust, Bill
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Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
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Offline 754

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Re: Cobra motor disassembly and rebuild
« Reply #403 on: June 27, 2016, 08:41:20 AM »
I think my RC sprocket has the holes drilled in new locations.. 4 additional holes..
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Offline Bill/BentON Racing

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Re: Cobra motor disassembly and rebuild
« Reply #404 on: June 27, 2016, 08:54:42 AM »
Early ones were drilled, later ones were slotted.
BentON Racing Website
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Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
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Offline PeWe

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Re: Cobra motor disassembly and rebuild
« Reply #405 on: June 27, 2016, 10:38:21 AM »
OK, I did not see the slot. Bolt head cover it if it is the photo on previous page. Shorter slot than APE and Falicon sprockets, right?
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline dragracer

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Re: Cobra motor disassembly and rebuild
« Reply #406 on: June 27, 2016, 12:49:02 PM »
OK, I did not see the slot. Bolt head cover it if it is the photo on previous page. Shorter slot than APE and Falicon sprockets, right?

I thought the same thing PeeWee. The picture made it seem to be fixed.  My RC sprocket has a larger slot.

Offline Bill/BentON Racing

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Re: Cobra motor disassembly and rebuild
« Reply #407 on: June 27, 2016, 02:20:00 PM »
Yep,  y'all are correct, slotted but not as much as some others!  And for what it's worth, on stock marks, intake was opening at 45 BTDC, should have been @ 31. Why you should degree your cam if possible,  Bill
BentON Racing Website
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BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
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Offline POPS 911

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Re: Cobra motor disassembly and rebuild
« Reply #408 on: June 28, 2016, 08:20:56 AM »
I was looking for the BLUE LOCK-TIGHT on the threads, better safe then sorry...........

Offline Bill/BentON Racing

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Re: Cobra motor disassembly and rebuild
« Reply #409 on: June 28, 2016, 09:49:29 AM »
It's on there, hell, I'll video next time! LMAO, thanks for checking though. Bill
BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
______________________________________
See our latest build 'Captain Marvel' CLICK HERE

Offline dragracer

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Re: Cobra motor disassembly and rebuild
« Reply #410 on: June 29, 2016, 10:14:30 PM »
Did you start it yet Bill?? Where's the new YouTube videos??

Offline Bill/BentON Racing

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Re: Cobra motor disassembly and rebuild
« Reply #411 on: June 30, 2016, 03:24:40 AM »
You will hear it soon enough! Lol.  Yes, she's up and running as of @,6:30 last night!  Yippee Kai Yeah,  it sounds good! Calling on dyno appointment today, sure do hope it works out. No elec trailer hookups for Memphis. Guess we get to listen to the generator for 3 days. Video later after work, Bill
BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
______________________________________
See our latest build 'Captain Marvel' CLICK HERE

Offline POPS 911

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Re: Cobra motor disassembly and rebuild
« Reply #412 on: July 01, 2016, 04:48:32 AM »
How many points on the shave and true job ????? Got the right new head gasket FOR THE NEW SQUEEEEEZE ?

Offline Bill/BentON Racing

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Re: Cobra motor disassembly and rebuild
« Reply #413 on: July 01, 2016, 04:58:38 AM »
Used a different head, Butch Pace one. It was ready to go on, was decked but don't recall how much. Yes , new Cometic copper. 050. Dyno on the 13/14th. Commerce next Friday night for some shakedown passes is the plan for now. Just finished up air shifter last night. Bill
BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
______________________________________
See our latest build 'Captain Marvel' CLICK HERE

Offline dragracer

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Re: Cobra motor disassembly and rebuild
« Reply #414 on: July 01, 2016, 11:48:08 AM »
Used a different head, Butch Pace one. It was ready to go on, was decked but don't recall how much. Yes , new Cometic copper. 050. Dyno on the 13/14th. Commerce next Friday night for some shakedown passes is the plan for now. Just finished up air shifter last night. Bill

Bill,

Bring that bike to Darlington tomorrow. ET bracket race. You and Donny can throw it on the back of the truck to save some gas. You won't need any wrenches cause the bike is perfect this time around. Anything else, I'll have in my trailer.

Offline Bill/BentON Racing

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Re: Cobra motor disassembly and rebuild
« Reply #415 on: July 01, 2016, 08:37:57 PM »
Gotta put on safer handlebars tomorrow.  I'll wait til Friday night.  Frank, this is like a new bike, everything has been changed. Better to make sure. Now if Friday works out, may run Commerce on Saturday,  Bill
BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
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See our latest build 'Captain Marvel' CLICK HERE

Offline dragracer

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Re: Cobra motor disassembly and rebuild
« Reply #416 on: July 02, 2016, 01:30:08 AM »
Understood Bill. I thought you had already changed the bars out. Also felt this could have been an opportunity for you to mainly make 1/4 mile test passes without the hassle of the Commerce crowd. This event will be going on all day. But I realize its a long distance to drive just to be sure your equipment is ready for Memphis. Nevertheless, get as much seat time as you can. The dyno results aren't going to teach you how to ride that bike, no matter how good the numbers look on paper.

Good luck at Commerce next week. We've only got 21 days left to get right.

Offline Bill/BentON Racing

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Re: Cobra motor disassembly and rebuild
« Reply #417 on: July 02, 2016, 04:40:49 AM »
Frank,  I changed them before Rockingham, but not the correct ones. Getting ready to install today, going try to make Friday night early, thanks, Bill
BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
______________________________________
See our latest build 'Captain Marvel' CLICK HERE

Offline POPS 911

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Re: Cobra motor disassembly and rebuild
« Reply #418 on: July 02, 2016, 06:21:19 AM »
Watched " GOT BRUCE " break the right bar off a set of Z-BARS right off the line = watched my rider Ron Saint break the left side off that type Z-BARS right off the hit, they both got stopped = LUCKY.  One piece bars I never seen broke, that welding on those Z- BARS and the chrome plating hide the rusting and cracking on the inside...... better be safe then sorry. Watched a top AHDRA Harley racer break off the triple tree at the big end at Bradenton 2002 and he got that Beast stopped. No bling bolts BILL !!!!!

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Cobra motor disassembly and rebuild
« Reply #419 on: July 02, 2016, 09:40:19 AM »
Amen to the most Reverend Pops Billie.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Bill/BentON Racing

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Re: Cobra motor disassembly and rebuild
« Reply #420 on: July 02, 2016, 10:07:05 AM »
That be Billy, if not Bill, not Billie! Lol.  Here's the new ones. POP's I agree. Thanks, Bill
BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
______________________________________
See our latest build 'Captain Marvel' CLICK HERE

Offline Bill/BentON Racing

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Re: Cobra motor disassembly and rebuild
« Reply #421 on: July 02, 2016, 04:25:01 PM »
New ones installed,  we real close!  Stay tuned,  Bill
« Last Edit: July 02, 2016, 04:26:32 PM by Bill/BentON Racing »
BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
______________________________________
See our latest build 'Captain Marvel' CLICK HERE

Offline madmtnmotors

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Re: Cobra motor disassembly and rebuild
« Reply #422 on: July 02, 2016, 06:47:11 PM »
You won't need any wrenches cause the bike is perfect this time around.

LOL!  ;D

I pictured Bill wandering around the pits picking up other peoples wrenches just to "hold them"!  ;)
TAMTF...


Wilbur



Projects:
"Evolution": http://forums.sohc4.net/index.php?topic=100352.0
"P.O. Debacle": http://forums.sohc4.net/index.php/topic,126692.msg1441661.html#msg1441661
F2/F3 O-rings: http://forums.sohc4.net/index.php?topic=113672.msg1300721#msg1300721
Cam Tower Studs: https://www.mcmaster.com/#93210a017/=t19sgp
Clean up that nasty harness: http://forums.sohc4.net/index.php?topic=137351.msg1549191#msg1549191
http://forums.sohc4.net/index.php/topic,148188.msg1688494.html#msg1688494
http://forums.sohc4.net/index.php/topic,139544.msg1579364.html#msg1579364
                                          
Charging system diagnosis: http://forums.sohc4.net/index.php?topic=1012.msg8345#msg8345
Get the manuals: http://manuals.sohc4.net/cb750k/
The Dragon: http://forums.sohc4.net/index.php?topic=45183.msg1571675#msg1571675
Headlight Switch: http://forums.sohc4.net/index.php?topic=113986.msg1283236#msg1283236
Branden's leak free top end thread: http://forums.sohc4.net/index.php?topic=107040.0
Engine Lifting Made Easy: http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742
                                      http://forums.sohc4.net/index.php/topic,100352.msg1675840.html#msg1675840
Static and Dynamic Timing: http://www.hondachopper.com/garage/carb_info/timing/timing1.html
Airbox Gasket Replacement: http://forums.sohc4.net/index.php/topic,114485.msg1290000.html#msg1290000
"Café" : http://forums.sohc4.net/index.php/topic,84697.msg953814.html#msg953814
PD Carb Choke Linkage: http://forums.sohc4.net/index.php/topic,100352.msg1669248.html#msg1669248
                                    http://forums.sohc4.net/index.php/topic,110931.msg1248354.html#msg1248354
                                    http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204
Follow up on your damn posts: http://forums.sohc4.net/index.php/topic,144305.msg1791605.html#msg1791605
Taiwanese Cam Chain Tensioners:  http://forums.sohc4.net/index.php/topic,155043.msg1774841.html#msg1774841
Gumtwo Seat Cover: http://forums.sohc4.net/index.php/topic,164440.msg1897366.html#msg1897366
Primary Drive: http://forums.sohc4.net/index.php/topic,166063.msg1919278.html#msg1919278
Tank Latch: http://forums.sohc4.net/index.php/topic,165975.msg1919495.html#msg1919495
Shorten your forks: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html DO NOT CUT THE SPRINGS!
Clutch How To: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-change-and-adjust-a-clutch-SOHC-td4040391.html
Late model K7/K8/F2/F3 front sprocket cover removal: http://forums.sohc4.net/index.php/topic,178428.msg2072279.html#msg2072279
630 to 530 conversion: http://forums.sohc4.net/index.php/topic,180710.msg2094423.html#msg2094423

Sent from my Tandy TRS-80!

Offline Bill/BentON Racing

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Re: Cobra motor disassembly and rebuild
« Reply #423 on: July 02, 2016, 07:31:13 PM »
LMAO,  I hope I'm in the glow of 10 second passes!  Sure feels good to be going next week to test and tune. Hope I'm done with this one for a while.  Bill
BentON Racing Website
OEM Parts | Service | Custom Builds
BentON Racing Facebook
Over 35 years of experience working on vintage motorcycles, with a speciality in Honda SOHC/4 with a focus on the CB750 and other models as well from 1966 - 1985.
______________________________________
1993 HRC RS125 | 1984 NS400R | 1974 Honda CB750/836cc (Calendar Girl) | 1972 CB 500/550 Yoshi Kitted 590cc | 1965 Honda CB450 Black Bomber | 1972 Suzuki T350 | 1973 88cc | Z50/Falcons Pit Bike | 1967 CA100| 1974 CB350 (400F motor)...and more.
______________________________________
See our latest build 'Captain Marvel' CLICK HERE

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Cobra motor disassembly and rebuild
« Reply #424 on: July 02, 2016, 07:31:34 PM »
That be Billy, if not Bill, not Billie! Lol.  Here's the new ones. POP's I agree. Thanks, Bill

LMMFAO.  ;D
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)