Author Topic: CB750 Oil flow?  (Read 1534 times)

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Offline jebon

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CB750 Oil flow?
« on: September 20, 2020, 05:30:06 am »
I got my newly acquired K0 started up but I'm worried about oil flow. Pressure light goes out when starting. I found out when I got it home that it had no oil in the sump. I put oil in it but looking down the tank the oil sits still when running. Am I in trouble? How can I check?
"Don't let schooling interfere with your education"
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CB750 K0 1971

Offline newday777

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Re: CB750 Oil flow?
« Reply #1 on: September 20, 2020, 05:46:48 am »
How did you figure out there wasn't oil in the sump? Was it shipped without oil in the bike?(over seas shipping companies usually require no oil or gas in bikes). Maybe if you had it shipped to you and prepped that they didn't start the bike but only put oil in the oil tank??
Your oil light goes out is a good indicator you have oil pressure. Remove a valve adjuster cap to see if you have oil flow to the top end.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline jebon

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Re: CB750 Oil flow?
« Reply #2 on: September 20, 2020, 05:54:24 am »
How did you figure out there wasn't oil in the sump? Was it shipped without oil in the bike?(over seas shipping companies usually require no oil or gas in bikes). Maybe if you had it shipped to you and prepped that they didn't start the bike but only put oil in the oil tank??
Your oil light goes out is a good indicator you have oil pressure. Remove a valve adjuster cap to see if you have oil flow to the top end.
I bought the bike locally. When I wanted to change the oil, nothing came out. So fire up the bike with a valve cap off?
"Don't let schooling interfere with your education"
---
CB750 K0 1971

Offline newday777

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Re: CB750 Oil flow?
« Reply #3 on: September 20, 2020, 06:21:02 am »
How did you figure out there wasn't oil in the sump? Was it shipped without oil in the bike?(over seas shipping companies usually require no oil or gas in bikes). Maybe if you had it shipped to you and prepped that they didn't start the bike but only put oil in the oil tank??
Your oil light goes out is a good indicator you have oil pressure. Remove a valve adjuster cap to see if you have oil flow to the top end.
I bought the bike locally. When I wanted to change the oil, nothing came out. So fire up the bike with a valve cap off?
First, kill switch off, spark plugs out and spin over with the starter to observe oil flow to the top end.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline jebon

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Re: CB750 Oil flow?
« Reply #4 on: September 20, 2020, 06:27:18 am »
How did you figure out there wasn't oil in the sump? Was it shipped without oil in the bike?(over seas shipping companies usually require no oil or gas in bikes). Maybe if you had it shipped to you and prepped that they didn't start the bike but only put oil in the oil tank??
Your oil light goes out is a good indicator you have oil pressure. Remove a valve adjuster cap to see if you have oil flow to the top end.
I bought the bike locally. When I wanted to change the oil, nothing came out. So fire up the bike with a valve cap off?
First, kill switch off, spark plugs out and spin over with the starter to observe oil flow to the top end.
I see oil flowing. Thanks
"Don't let schooling interfere with your education"
---
CB750 K0 1971

Offline ekpent

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Re: CB750 Oil flow?
« Reply #5 on: September 20, 2020, 06:31:25 am »
 You should see oil circulation in the oil tank running plus bubbles etc.

Offline newday777

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Re: CB750 Oil flow?
« Reply #6 on: September 20, 2020, 06:34:56 am »
Good to hear you have flow. Yes you should see some bubbles and movement in the tank when running.
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline jebon

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Re: CB750 Oil flow?
« Reply #7 on: September 20, 2020, 07:33:04 am »
Good to hear you have flow. Yes you should see some bubbles and movement in the tank when running.
Just took it for a very short ride (1 min)
When I got back I had white smoke from 1 and 4
"Don't let schooling interfere with your education"
---
CB750 K0 1971

Offline PeWe

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Re: CB750 Oil flow?
« Reply #8 on: September 20, 2020, 11:25:24 am »
When draining oil without oil filter and cover.

Do not spin starter too long until oil stop coming.

It takes long time to get pressure when oil is refilled, new filter w cover on.

Plugs off unloads the crank a little and let it spin easier.
CB750 K6-76 1005cc JMR Billet block.
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 BenelliSEI

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Re: CB750 Oil flow?
« Reply #9 on: September 20, 2020, 12:48:01 pm »
White smoke can be condensation or moisture burn off. Have you changed out the old gas? Drain the tank and put fresh fuel in. Get it hot and change the oil and filter.......

Offline bryanj

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Re: CB750 Oil flow?
« Reply #10 on: September 20, 2020, 01:45:31 pm »
Need to get it evenly hot, i would say at least 20 mins riding(not in traffic) before seeing what smoke you get
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline newday777

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Re: CB750 Oil flow?
« Reply #11 on: January 22, 2021, 10:27:21 am »
Good to hear you have flow. Yes you should see some bubbles and movement in the tank when running.
Just took it for a very short ride (1 min)
When I got back I had white smoke from 1 and 4

Any further results to update?
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline ekpent

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Re: CB750 Oil flow?
« Reply #12 on: January 22, 2021, 04:20:30 pm »
Good to hear you have flow. Yes you should see some bubbles and movement in the tank when running.
Just took it for a very short ride (1 min)
When I got back I had white smoke from 1 and 4

Any further results to update?
Looks like the engine is apart for a rebuild and paint. Current thread going on now. http://forums.sohc4.net/index.php/topic,185069.0.html

Offline jebon

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Re: CB750 Oil flow?
« Reply #13 on: January 24, 2021, 02:52:21 pm »
Good to hear you have flow. Yes you should see some bubbles and movement in the tank when running.
Just took it for a very short ride (1 min)
When I got back I had white smoke from 1 and 4

Any further results to update?
Looks like the engine is apart for a rebuild and paint. Current thread going on now. http://forums.sohc4.net/index.php/topic,185069.0.html
Thank you. Sorry for the multiple threads
"Don't let schooling interfere with your education"
---
CB750 K0 1971