Author Topic: I bought my first CB750 SOHC K7😍😀  (Read 2616 times)

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Offline MDC69

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I bought my first CB750 SOHC K7😍😀
« on: December 19, 2019, 04:59:07 AM »
Hello everyone,
Thanks for letting me join you. I have realised there are some benefits to turning 50. I spotted a really original 77 CB 750 SoHC on eBay. So I bought it. It was sold as a runner. I have always admired the CB of the 70s. As a young boy I would look in admiration at them flying about my neighborhood in Nottinghamshire. I now have one YAY!!! The bike doesn't run tuck delivery yesterday, I have put the battery on charge and I am hoping and praying that's the only reason it's not starting. Please pray to the bike god's for me.

Thanks again.

Offline BenelliSEI

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #1 on: December 19, 2019, 05:29:03 AM »
Welcome and good luck! I started with a K8, years ago. Wonderful machines....... put some fresh gas in it too.

Online rocket johnny

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #2 on: December 19, 2019, 06:33:20 AM »
welcome to the club !    happy holidays ! !

Online Stev-o

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #3 on: December 19, 2019, 07:17:33 AM »
Welcome from Texas.   

Fully charge battery and use this starting procedure:  Give full choke and no throttle 'til she fires.

Good luck
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline MDC69

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #4 on: December 19, 2019, 10:16:38 AM »
thanks for the tips guys, just tested the compresion on cylinder 1, only getting 60 psi. surely that would never run

Offline jakec

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #5 on: December 19, 2019, 10:46:10 AM »
compression test is pointless if you already bought it. you might have done the test wrong anyways if it's that low.
1970 CB750 K0
1977 CB750 Chop
1997 XR650L

Online Stev-o

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #6 on: December 19, 2019, 02:05:25 PM »
If you are using an automotive tester, that will not be accurate.  Did you have the throttle fully open?

More important than the pressure number is how they compare to each other. 
What were the others?
All should be within 10%
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline MDC69

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #7 on: December 19, 2019, 02:53:04 PM »
I will do the test on all cylinders with throttle full open and report back to you. thanks

Offline seanbarney41

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #8 on: December 19, 2019, 04:51:35 PM »
If the bike has not been run in years, compression numbers don't mean much, even if correctly obtained.  Rings are probably slightly stuck in the piston ring lands and will free up quick with some heat, movement, vibration, and fresh oil.
If it works good, it looks good...

Online Stev-o

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #9 on: December 20, 2019, 02:50:34 PM »
If the bike has not been run in years, compression numbers don't mean much, even if correctly obtained.  Rings are probably slightly stuck in the piston ring lands and will free up quick with some heat, movement, vibration, and fresh oil.

So true, Sean.  But in his first post, he states the bike was bought as a "runner"...
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline tool14

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #10 on: December 20, 2019, 03:20:17 PM »
welcome aboard and good luck with bike.

Offline MD

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #11 on: December 20, 2019, 03:27:19 PM »
Welcome from Lake Superior,

-MD
1975 CB550F Super Sport;  Lake Superior Circle 1000, 45-90 Saddle 1000, All in Yooper 1000 and SS 2000 in 48 hrs:  1985 GL1200A, MN in State SS1K

Offline MDC69

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #12 on: December 21, 2019, 01:39:41 AM »

Offline Johnie

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #13 on: December 21, 2019, 08:28:19 AM »
Nice...another one saved. Don't run it to long without a fan on this air cooled engine. My first new bike was the K7. Here's a pic of when I brought it home from the dealer.
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA

Offline MDC69

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #14 on: December 21, 2019, 10:51:25 AM »
Thank you for the advice. Nice bike 👍

Offline Kevin D

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #15 on: December 21, 2019, 03:56:57 PM »
HAH MDC, you have brought the CB into the family room, with the Mrs. consent! How did you manage that?!?!

71 CB750 K1
104,000 miles
Original Owner
———past———
70 SL100/125/150
70 Candy BlueGreen CB 750 K0
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Former Honda parts kid/counter kid/do all
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Whether you think you can or think you can’t, you’re right
Genius is 99% perspiration, 1% inspiration

Offline Erny

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #16 on: December 22, 2019, 11:09:04 AM »
MDC, congrats!

Another beautiful K7 saved!
I'm happy owner of one too (the same black excell color) so just ask if you will need something, folks here are always willing to advice and help.
If not a secret how much you paid for her?
CB750K K7 USA model (1977)
CB550K1 USA model (1975)

Offline MDC69

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #17 on: December 27, 2019, 05:02:21 PM »
HAH MDC, you have brought the CB into the family room, with the Mrs. consent! How did you manage that?!?!

Its not the family room, its my man cave :)

Offline MDC69

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #18 on: December 27, 2019, 05:05:13 PM »
MDC, congrats!

Another beautiful K7 saved!
I'm happy owner of one too (the same black excell color) so just ask if you will need something, folks here are always willing to advice and help.
If not a secret how much you paid for her?

Thank you. 4k sterling
« Last Edit: December 27, 2019, 05:07:26 PM by MDC69 »

Offline JamesReid

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #19 on: January 05, 2020, 07:47:42 PM »
Hi mate welcome to the forum, i hope you enjoy the community and we learn a lot from each other.

Offline MDC69

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #20 on: January 11, 2020, 08:44:40 AM »
thanks for the warm welcome.

I have question, Speaking with a chap in the pub and he says that the Pilot Screw isnt a pilot screw its a mixture screw and it doesnt need the washer O ring, these for other models. is this true? I am currently struggling with the idle speed.

valve clearance, timing, carb floats checked, carbs cleaned and passage ways checked, new pilot screws and float valves fitted.

thanks

Offline BenelliSEI

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #21 on: January 11, 2020, 09:42:09 AM »
Not sure about the pilots screw “0” ring, check the K7/8 parts list. If it shows it, use it......
Another cause of hanging idle is a sticking mechanical advancer. Staying to long at full advance makes the idle stay up, and then drop when the advancer shakes loose and retards ignition. It needs to be clean and free on the spool.

Online Stev-o

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #22 on: January 26, 2020, 02:35:51 PM »


I have question, Speaking with a chap in the pub and he says that the Pilot Screw isnt a pilot screw...

Was he drunk?!

The "pilot" screw is not for adjusting idle, it is for mixture.  Do you have a manual?
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline MDC69

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #23 on: February 01, 2020, 05:31:29 AM »
Hi Steve-o

I have since figured out its a mixture screw.  yes I have a Haynes manual. not much detail on the K7.

I am finding that the screw on carb 2 doesnt need to be turned out as far, 3 quarters to 1 turn out. whilst carbbs 1,3 and 4 are between 1.5 to 2 turns out. is this the same everyone else experience?

Offline BenelliSEI

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Re: I bought my first CB750 SOHC K7😍😀
« Reply #24 on: February 01, 2020, 10:40:07 AM »
MDC....... I usually set them all at whatever the manual suggests for your year. Then use my manometer set to do a carb sync. After that, in and out 1/2 to 3/4 of a turn makes no difference, so I leave them alone.......