Author Topic: Thoughts on Oil  (Read 1587 times)

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Offline Hospitaller

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Thoughts on Oil
« on: September 20, 2024, 01:52:27 PM »
I know the consensus seems to be that 20w50 is the best for my k4 for longevity.  I was gifted a case of Honda GN4 in 10w40 which is what the book calls for.  It shouldn't hurt my girl to use this oil up and then go back to 20w50, should it?  I figure I have way bigger problems currently since I need new cables and resistors, points, a transistorized ignition, plugs, coils, to get the keyster metering rods out of my carbs because even at 4600ft the plugs are ever so slightly too white, on and on. Oh yeah, and swing arm bushings... it never ends does it?
Diplomacy is the art of saying 'Nice doggie' until you can find a rock. -Will Rogers
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Offline bryanj

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Re: Thoughts on Oil
« Reply #1 on: September 20, 2024, 02:51:33 PM »
What resistors, non i know of on 750
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: Thoughts on Oil
« Reply #2 on: September 20, 2024, 03:10:00 PM »
What bike are you on?
What is the temperature outside 🤔???
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 have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline Tracksnblades1

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Re: Thoughts on Oil
« Reply #3 on: September 20, 2024, 04:00:36 PM »
You can check your spark plug plug wire caps to see if they need replaced.  But new ones are pretty 😁
« Last Edit: September 20, 2024, 04:02:36 PM by Tracksnblades1 »
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Offline HondaMan

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Re: Thoughts on Oil
« Reply #4 on: September 20, 2024, 06:46:29 PM »
Darn...I thought this was an oil thread.
;)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline bryanj

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Re: Thoughts on Oil
« Reply #5 on: September 21, 2024, 12:09:54 AM »
Please no!!!
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 dave500

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Re: Thoughts on Oil
« Reply #6 on: September 21, 2024, 02:40:52 AM »
you see its like this,an oily resistor is more slippery.

Offline bryanj

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Re: Thoughts on Oil
« Reply #7 on: September 21, 2024, 03:34:56 AM »
Dave, i know people say it aint possible but you really do get worse mate!!!
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 dave500

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Re: Thoughts on Oil
« Reply #8 on: September 21, 2024, 04:56:58 AM »
im glad you called me mate!

Offline bryanj

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Re: Thoughts on Oil
« Reply #9 on: September 21, 2024, 05:28:13 AM »
We are too bloody similar not to Dave, both creakey and drivers for a start!
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 BenelliSEI

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Re: Thoughts on Oil
« Reply #10 on: September 21, 2024, 02:36:21 PM »
I know the consensus seems to be that 20w50 is the best for my k4 for longevity.  I was gifted a case of Honda GN4 in 10w40 which is what the book calls for.  It shouldn't hurt my girl to use this oil up and then go back to 20w50, should it?  I figure I have way bigger problems currently since I need new cables and resistors, points, a transistorized ignition, plugs, coils, to get the keyster metering rods out of my carbs because even at 4600ft the plugs are ever so slightly too white, on and on. Oh yeah, and swing arm bushings... it never ends does it?

Use it up. Good stuff.

Offline CB750R

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Re: Thoughts on Oil
« Reply #11 on: September 23, 2024, 06:33:42 AM »
Use it in spring or fall, use the 20w50 in the summer!!

Offline willbird

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Re: Thoughts on Oil
« Reply #12 on: September 23, 2024, 08:36:07 AM »
If we looked at the "body of work" of the lifetimes of all of our bikes combined I'd bet a cold soda that 10w40 oil was used more than anything else.

That does not mean it is "optimum" of course.

Bill

Offline Stev-o

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Re: Thoughts on Oil
« Reply #13 on: September 23, 2024, 09:07:22 AM »
Ok, I'm gonna type it, any oil will work!  But some better than others, I just wont use synthetic for clutch reasons.
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline Tracksnblades1

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Re: Thoughts on Oil
« Reply #14 on: September 23, 2024, 11:14:58 AM »
FWIM  I’ve always used 20w-50 Vavoline it has excellent high temp load carrying capacity..not the best but not the worst. However now that Vavoline offers motorcycle 4stroke oil, the conventional 20w-50 is no longer recommended for wet clutch operation….

Just for a FYI. Since 2007, Honda’s motorcycle manuals calls for 10w-30 instead of the forever 10w-40 recommendations. 

If you look at the crankshaft clearances of Honda’s modern air cooled engines compared to these old SOHC’s clearances, you’ll see nothing has changed, clearances wise..
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Offline HondaMan

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Re: Thoughts on Oil
« Reply #15 on: September 23, 2024, 11:22:22 AM »
If you look at the crankshaft clearances of Honda’s modern air cooled engines compared to these old SOHC’s clearances, you’ll see nothing has changed, clearances wise..

True, but their modern oil pumps deliver almost 2x as much oil flow, too! :)
In the older cars we learned that we could drive them way over 100k miles if we switched to 'hi output' oil pumps, which were available for almost every Detroit engine made. I did it with several of my Ford engines and they rolled over 200k (and one over 460k) miles with ease.
« Last Edit: September 23, 2024, 11:24:42 AM by HondaMan »
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline jonda500

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Re: Thoughts on Oil
« Reply #16 on: September 23, 2024, 05:41:54 PM »
If we looked at the "body of work" of the lifetimes of all of our bikes combined I'd bet a cold soda that 10w40 oil was used more than anything else.

That does not mean it is "optimum" of course.

Bill
+1
I used 10w40 diesel oil in my CB450 for ten years with no problems! John
Remember that an ignoramus is only someone who doesn't know something you just learned yesterday!

A starter clutch thread:
http://forums.sohc4.net/index.php/topic,122084.0.html
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1972 CB500K1 returned to complete/original condition
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http://forums.sohc4.net/index.php/topic,149161.msg1711626.html#msg1711626
197? CB500/550 constructing from left over parts
1998 KTM 380 (two stroke) recent impulse buy, mmmm...

Offline beemerbum

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Re: Thoughts on Oil
« Reply #17 on: September 24, 2024, 03:08:55 PM »
Read somewhere that a high zinc content is good for M/C oil. If so, why?

Online Don R

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Re: Thoughts on Oil
« Reply #18 on: September 24, 2024, 04:53:09 PM »
 Zinc smears itself into high pressure contact points and keeps the parent metals from rubbing directly on each other. HA! Here we go! I'm likely wrong and don't care, flame away!
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Offline HondaMan

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Re: Thoughts on Oil
« Reply #19 on: September 24, 2024, 06:35:10 PM »
Zinc smears itself into high pressure contact points and keeps the parent metals from rubbing directly on each other. HA! Here we go! I'm likely wrong and don't care, flame away!
Bullseye!
:D
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline willbird

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Re: Thoughts on Oil
« Reply #20 on: September 25, 2024, 08:18:36 AM »
Zinc smears itself into high pressure contact points and keeps the parent metals from rubbing directly on each other. HA! Here we go! I'm likely wrong and don't care, flame away!

The "motor oil geek" Lake Speed Jr has a lot of youtube videos on engine oil chemistry, worth looking him up and giving them a view.

Offline Hospitaller

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Re: Thoughts on Oil
« Reply #21 on: September 25, 2024, 09:13:50 AM »
What resistors, non i know of on 750
The spark plug caps, Mine could be factory.  I measured them a while ago and they were pretty much out of spec. The ones I could get to, someone glued the cables into most of them. 

What bike are you on?
What is the temperature outside 🤔???
750K4, 90F now, in three months 20F or below.  I still ride if the roads are clear and dry. It doesn't snow that much in the Salt Lake Valley in Northern UT it is just doggone cold.
 
True, but their modern oil pumps deliver almost 2x as much oil flow, too! :)
Truth, and being an Automotive Tech/Hot Rod builder, I'm always in favor of more oil flow.  Is that an option for this engine? You will probably see it in the next couple of years anyway to fix core shift and possible blueprinting/streetable mods(new rocker shafts, light port work, clutch oiling mods etc.) I just want to take the best care of her I can until then.
Diplomacy is the art of saying 'Nice doggie' until you can find a rock. -Will Rogers
1974 CB750K4

Offline Swoop

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Re: Thoughts on Oil
« Reply #22 on: September 25, 2024, 09:21:57 AM »
What resistors, non i know of on 750


I think he’s talking about them there resistors that capacitate

Offline Deltarider

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Re: Thoughts on Oil
« Reply #23 on: September 26, 2024, 12:23:39 AM »
For my 48 year old engine the most important characteristic of an oil is, it will be nice for the rubbers. I have best results with Castrol GTX 15W-40, aka High Mileage. It even cured the shifter seal and so the new one is still in its plastic bag. There are more rubber parts inside our engines than people think...
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Online rotortiller

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Re: Thoughts on Oil
« Reply #24 on: September 26, 2024, 06:20:20 AM »
Oil is like beer, you have the taste and you have the alcohol content. I tend to pick a major brand, change it often enough, stick with it, and select the 10W40 general oil weight spec'd by Honda, Suzuki, etc of that era. I like to go by decades on the planet, a 45+ year old bike (s) with tens of thousands of klicks, and a slew of empty oil cans to form my opinion.  Lots of stuff is invented concerning our secret sauce, kind of like tainted versions of history lol. Taken to extremes an incorrect beer choice can cause the runs, but also very important is to remember that oil is like beer in another very important way, you only rent it for a short period of time.