Topic: Silly but Serious Oil Change Question

[HondaMan]

Except of course, for the ten or fifteen seconds it took the oil light to go off during the testing of compression on #1, and the several seconds it took for the light to go off testing the others.

What weight oil are you using?

[robvangulik]

The 750 oil pump consists of two parts, the scavenge part pumps volume, to keep the oil pan empty, the supply part gives pressure to the system....

[PeWe]

I have done oil change when I drained a little more by the starter splashing out old black oil where the filter should sit. Just a few sec...2-3...

Not fun to whitness the much longer time red light was shining at the start when new oil was filled and dry filter.

If you really want to get more oil out try tipping the bike way over to the side till the foot peg almost hits the ground especially when tipping to the left. You will be surprised at how much more oil will come out the drain plug when you put it back upright. I do this on my 750's when changing oil.

Did that too, warm engine.
This is enough for a good oil change.

Last change I gave oil bolt a viton o-ring from my engine o-ring collection.  (Plus a 89x4.5mm nitrile o-ring as the last changes before.)

No oil leak at front that looked like weaping cases.
No need to pull engine for re-seal cases as it look like today.

(O-rings delivered with oil filters usually too thin.)

I have done several compression tests on both my CB750's.
But with oil.
Cheap tester bought to verify that all 4 cylinders are equal.
Later test to see if something has happened.

I took photos of the gauge, noted which cylinder and saved for future.

Also to verify what different hot cams will do with compression.

Found that a modified CB750 need over 200PSI to deliver power.

Stock CB750 K2 with later 61.50mm K7/K8 Cruzinimage pistons end up in +170PSI.

Cruzinimage stock 61.00mm pistons 150-160PSI.
A little bit peppier engine.

[Deltarider]

One of my good buddies, that has several beautifully maintained old Hondas, only changes the filters on alternate oil changes. He swears we are all excessive! He may be right, but for the cost of a filter I’m not playing that game…..Oil and filters are the cheapest insurance you can buy and the only Honda engines I’ve seen totally destroyed were from lack of oil.

Personally I'm with your buddy. Also I change the filter every 2^nd oil change. IMO 'the cheapest insurance' is to abstain from not needed and therefore irrational 'maintenance'. Not only that Honda thought it was OK, the filter is overdimensioned for its task. Please realise that the difference between a new and a totally worn engine is a teaspoon of metal at most. Secondly, there's a lot that can go wrong replacing that filter with O-rings misaligned etc. Multiple examples in this here forum. IMO it's overnursing your bike and is in the same category as fitting extra inline fuel filters which can do more wrong than good.
Some go even as far as, after draining the oil, to crank the engine to get even the last oil out.
Don't. The new oil you are about to pour in, is perfectly capable to deal with that tiny little bit of oil left in the engine. Again, you may do more harm than good. Leave that oil where it is, in the journals and up in the head to shorten the time during the next start where the new oil has to build up pressure and be pumped up. This overnursing indicates to an imo neurotic attitude.

[Rosinante]

So what were your compression readings?

Most were around 140, but #4 still has a problem.  Valve problem I think.  HondaMan thought the problem might clear up after a good long ride, but the problem now persists after a spirited 350-mile day last week.  I suppose this is not so unusual.  HondaMan says the valve guides in the K7-8 bikes are worn at 15K.  This bike has 38K.

[Rosinante]

Except of course, for the ten or fifteen seconds it took the oil light to go off during the testing of compression on #1, and the several seconds it took for the light to go off testing the others.

What weight oil are you using?

20w50

All year.  Our weather is rather mild here, and I don't ride motorcycles in the cold.

[PeWe]

Oil vs filter change.
People that change filter every 2nd oil change might change oil very frequent?

Good oil,  correctly tuned with carbs correct is for me ok for a 5000km interval, oil and filter.

Rides in very hot climate as constant +30-40*C need probably more freqent changes.
Using a temperture gauge in oil tank will show oil temp.
If always only 100-115*C (212-230*F) no excessive temp.
My temp gauge has red from 120*C (248*F)

A good synthetic will live longer in higher temps.

Check Porsche forums about oil temps and oils in air cooled engines.

A look outside filter is interesting, verify no issues.

Open oil pan for another look and pump strainer clean also good 1000km after an engine rebuild.

I'll be curious next 10.000km.
If OK then, maybe 20.000km for next pan removal if nothing happens or revealed by filter.

[HondaMan]

So what were your compression readings?

Most were around 140, but #4 still has a problem.  Valve problem I think.  HondaMan thought the problem might clear up after a good long ride, but the problem now persists after a spirited 350-mile day last week.  I suppose this is not so unusual.  HondaMan says the valve guides in the K7-8 bikes are worn at 15K.  This bike has 38K.

This is typical of the worn guide(s) in these engines. It doesn't cause a big problem if the intake guide is the culprit, but if it is the exhaust guide then oil starts showing up around the exhaust pipe, making a mess of things. I've [too often] seen the heads removed with someone just replacing the valve guide seals, cleaning up the valves and seats, and all things reassembled (all that work!) without replacing the guides, only to get the same mess again, right away.

The bike will run OK for the season, though. It doesn't hurt anything.

[Rosinante]

Some folks recommend changing oil without changing filter.  Others recommend changing filter without changing oil.  I have never done either, nor will I.  I may be dumb but I'm not stoopid. 

The bike will run OK for the season, though. It doesn't hurt anything.

The bike runs well, I have to say.  And I agree about the folly of not replacing guides.  Guides are what transfers heat out of the exhaust valve.  They also allow the valve to seat properly.  At the rate of 70 times per second (at 8500 rpm).  Guides are important.

This engine is fine for now, but needs a head refresh at least.  Adding oil to the cylinder does not affect compression performance.  The rings might be fine, and the main and rod bearings.  I rebuilt an air-cooled six cylinder car engine once at 186K miles and the bearings were fine, as were the cylinders.  New bearing shells and rings, and new valves, guides and seals.  Runs like a champ now.

I'm not going to rebuild this bike.  I am likely to sell her, fairly soon.  She's a BLAST, but I guess I am not looking for a motorcycle that is a blast.  I think I want a Boxer twin.

[willbird]

At work we have 2500 ton hydraulic presses that use 600-800 gallons of AW68 and in some cases AW100 hydraulic oil. We have nearly 40 of them. We use oil analysis to decide when oil gets changed. We also make sure temp never goes over 130F and we change 30 micron filters on a really good interval.

I'd like to send some off from my bike to Blackstone maybe.

What is going on at 1500 miles might tell me if it is better to get the oil out that a filter change gets to, or if that does not matter that much.Not much added cost to swap the filter tho and get that oil out.

Even with modern vehicles opinions vary widely. My 2021 5.7 Tundra takes like 11 quarts of oil and Toyota oil change interval is 10k, people have sent oil off and Blackstone said it was fine, told them to try 11K next time. I am at 35k on that truck and so far have done it at 5k. Some so called dealer mechanics swear modern vehicles NEED it at 3k if city driven. They claim "blackstone does not check everything".

Bill

[Tracksnblades1]

Your local Caterpillar, CaseIH, John Deere provide the same service for probably half the cost of the industrial charge..

[dave500]

if anything with new modern fuel injected engines with precision tolerances youd expect way less blow by and less oil contamination from fuel etc?ill bet theyd go 15000 kays before really needing a change?10,000 is safer?short run cold engines should be done earlier,id say 5000.

[PeWe]

It depends on engine with total amount of oil and if there is a turbo.
Remember the oil sludge case 2010-2011
https://topclassactions.com/lawsuit-settlements/lawsuit-news/vw-audi-oil-sludge-class-action-settlement/

Here silly oil intervals of ca 25.000km.
"Longlife" fraud. Engine will give up for the 2nd owner after ca 150.000 km.

I have an Audi with 1.8T engine. 
It got 2 Bilstein engine flush within a year to remove sludge when I heard about it when I visited a shop upgrading the software for more power. The guy complained on oil with hard particles, carbon. This was before the class action in USA.

Last engine flush after I added oil flush additive in oil outside the shop and let it idle for 20 minutes at 2000rpm to desolve sludge the Bilstein Engine flush does not catch when that is done with not running engine. Made a difference.

Toyota had a class action at the same time.

Toyota updated oil interval to 8000km if driving mostly in city, many cold starts, short distances.

That is the interval that match my car too. Oil feels bad at 10.000km. Like old oil mixed with naphta. Viscosity totally shot.

That small engine with 3.7L oil (with biggest filter possible to fit) the turbo will cook oil into bitumen if not change oil more frequent.

It get a typical synthetic oil (PAO as best) not the better esther synth. VW 505.00 on label.
I do not trust the thinner "Longlife" oils for this engine.

Not that many cars as mine on the roads nowadays. Probably damaged engines when oil pump is clogged with sludge. Too expensive to fix. Pull engine and maybe replace it cost more than another better car so car to scrap yard.

I'm used to feel better oil between my fingers when working with my bikes.

[dave500]

reminds me of lubed for life transaxles on riding mowers etc?surely removing old stuff and replacing with new has to work?

[bryanj]

You want to talk mileages
Paccar 14 ltr diesel holds 35ltr of oil and is changed at 180,000km

[Tracksnblades1]

You want to talk mileages
Paccar 14 ltr diesel holds 35ltr of oil and is changed at 180,000km

Cummins and Cats hold 10 gallons. 11 if they have dual oil filters…

[willbird]

You want to talk mileages
Paccar 14 ltr diesel holds 35ltr of oil and is changed at 180,000km

Cummins and Cats hold 10 gallons. 11 if they have dual oil filters…

And some mfg had a documented procedure where the oil drained OUT could be poured right into the nearly full fuel tanks on the truck. 10 gallons into 250 gallons would be the rough ratio ?

[bryanj]

Not any more with adblue and nox treatment plus dpf

[Tracksnblades1]

You want to talk mileages
Paccar 14 ltr diesel holds 35ltr of oil and is changed at 180,000km

Over here the on road trucks getting over 6 mile per gallon had different oil change intervals than heavily ladened (soot) ones  averaging below 5 mpg…

You want to talk mileages
Paccar 14 ltr diesel holds 35ltr of oil and is changed at 180,000km

Cummins and Cats hold 10 gallons. 11 if they have dual oil filters…

And some mfg had a documented procedure where the oil drained OUT could be poured right into the nearly full fuel tanks on the truck. 10 gallons into 250 gallons would be the rough ratio ?

Yep, a BTU is a BTU….a 3 micron fuel filter may catch all the soot but I’m not sure whether there would be an economical payback. BTU fuel savings vs Final fuel filter price….some are very pricey…

[willbird]

You want to talk mileages
Paccar 14 ltr diesel holds 35ltr of oil and is changed at 180,000km

Over here the on road trucks getting over 6 mile per gallon had different oil change intervals than heavily ladened (soot) ones  averaging below 5 mpg…

You want to talk mileages
Paccar 14 ltr diesel holds 35ltr of oil and is changed at 180,000km

Cummins and Cats hold 10 gallons. 11 if they have dual oil filters…

And some mfg had a documented procedure where the oil drained OUT could be poured right into the nearly full fuel tanks on the truck. 10 gallons into 250 gallons would be the rough ratio ?

Yep, a BTU is a BTU….a 3 micron fuel filter may catch all the soot but I’m not sure whether there would be an economical payback. BTU fuel savings vs Final fuel filter price….some are very pricey…

Not sure what the logic of that mfg was. It could provide a documented drain oil disposal method in remote areas without having to store the oil and haul it out of there I suppose.

[TwoTired]

Some years ago I stumbled across an interesting experiment/study on oil analysis between oil changes in motorcycle engines.  One of the points that was exposed is that our transmissions are lubed by the engine crankcase oil.  The constant gear meshing applied far more shear forces to the oil than when oil used solely in engine crankcases as is common in automotive uses.

The report found that multi viscosity oil blends reverted to base stock viscosity much sooner in motorcycles.  The explanation is that when the oil is formulated, additives are included to make the base stock behave as thicker oil (higher shear strength) when hot by these additives.  They explained that part of the additive package introduced long chain molecules that shrunk when cold and extended when hot.  The reaction to temperature is what gave the oil the higher viscosity behavior when hot.  The transmission's gears chop up the long chain additive molecules, with the result that the oil looses its viscosity modification rating, which reduces the shear strength of the oil during progressive use.

IIRC:
The study had oil analysis samples at 200 mile intervals.  They used a liquid cooled engine, in order give the oil a more stable oil temp throughout its use.  (This is something air cooled engines do not have the luxury of providing, and excessive heat is well known to reduce oil effectiveness damaging both the base stock and oil additive package molecules.)

Anyway the study showed a sharp decline in long chain molecules at around 1000 miles of use.  Meaning a 10W-40 oil was effectively a 10W-30 oil at 1000 miles.  This tapered down to 10W-15 at about 1500 miles.  By 2000 miles the oil analysis showed that the oil has lost all of it's multivis properties.

Bear in mind, that study was at least 15 maybe 20 years old by now.  Perhaps they have more robust long chain molecules in today's additive packages. Oil formulation details are quite secretive by oil companies, relying far more on marketing claims of "better" and "testimonial innuendos" than any objective performance data or chemistry specifics.   
However, I found it curious to note oil behavior in my CB550's.  The metric noted by me was effectiveness of the clutch and it's tendency to begin dragging at right around 1000 miles (varies with seasonal temps), and getting clunky shifts, harder to select neutral, from that point on, towards my 1500 miles oil change interval.  The clutch drag and clunky shifting went away very shortly if not immediately after the oil change. 

Perhaps you'll find interest in this, yet another, oil thread discussion.

[willbird]

Some years ago I stumbled across an interesting experiment/study on oil analysis between oil changes in motorcycle engines.  One of the points that was exposed is that our transmissions are lubed by the engine crankcase oil.  The constant gear meshing applied far more shear forces to the oil than when oil used solely in engine crankcases as is common in automotive uses.

The report found that multi viscosity oil blends reverted to base stock viscosity much sooner in motorcycles.  The explanation is that when the oil is formulated, additives are included to make the base stock behave as thicker oil (higher shear strength) when hot by these additives.  They explained that part of the additive package introduced long chain molecules that shrunk when cold and extended when hot.  The reaction to temperature is what gave the oil the higher viscosity behavior when hot.  The transmission's gears chop up the long chain additive molecules, with the result that the oil looses its viscosity modification rating, which reduces the shear strength of the oil during progressive use.

IIRC:
The study had oil analysis samples at 200 mile intervals.  They used a liquid cooled engine, in order give the oil a more stable oil temp throughout its use.  (This is something air cooled engines do not have the luxury of providing, and excessive heat is well known to reduce oil effectiveness damaging both the base stock and oil additive package molecules.)

Anyway the study showed a sharp decline in long chain molecules at around 1000 miles of use.  Meaning a 10W-40 oil was effectively a 10W-30 oil at 1000 miles.  This tapered down to 10W-15 at about 1500 miles.  By 2000 miles the oil analysis showed that the oil has lost all of it's multivis properties.

Bear in mind, that study was at least 15 maybe 20 years old by now.  Perhaps they have more robust long chain molecules in today's additive packages. Oil formulation details are quite secretive by oil companies, relying far more on marketing claims of "better" and "testimonial innuendos" than any objective performance data or chemistry specifics.   
However, I found it curious to note oil behavior in my CB550's.  The metric noted by me was effectiveness of the clutch and it's tendency to begin dragging at right around 1000 miles (varies with seasonal temps), and getting clunky shifts, harder to select neutral, from that point on, towards my 1500 miles oil change interval.  The clutch drag and clunky shifting went away very shortly if not immediately after the oil change. 

Perhaps you'll find interest in this, yet another, oil thread discussion.

That would be an interesting test to replicate with modern oils

I just sent Blackstone a request for a test kit. I’m at about 1k on rotella t6 15w40 right now

[PeWe]

Very interesting how fast the oil viscosity degrades.

I read similar post on a Porsche forum where a very experienced race shop guy tested oil and saw a degradation of viscosity very soon.
That oil was not used in a transmission, engine only.

Important to use correct viscosity was the message in that thread. 20W-50 for the old engines.
He had seen the result when owners had used thinner oils 10-40 synthetic with bad result.

Cam chain tensioner needed oil pressure wich did not work with thinner oil. Guides worn quick when the lubrication was based on splashes of oil, the thicker oil those engines needed.

CB750 spec 20W-50.

CB500/550 use thinner, 10W-40?


I have used this one for a while.
The comment about gearbox sounds good.

https://eurol.com/sv/produkter/eurol-harley-twinlube-fs-20w50/

A modern, synthetic oil, especially developed as an ‘overall lubricant’ for robust HD V-Twin motorcycles.

Guarantees a robust lubricating film, even at high temperatures and speeds. It assures perfect engine performances under all driving and weather conditions in touring, racing and long distance driving application.

Because of the excellent shifting characteristics, it can also be applied in gearboxes, clutches (primary and secondary chain cases), whether or not integrated in the engine.

Performance level
API SJ
JASO MA
JASO MA2

[ofreen]

One of these days (probably in the winter if there isn't something else going on) I'll put the maintenance record for my '75 750F that now has over 168,000 original miles on it in the ongoing XX Years on a '75 750F thread I started years ago.  Or maybe on the highest mileage thread.  At any rate, my oil change regimen for many, many years has used a 3000 change interval (there was a time when I went 4000), with a filter change every other time.  Spectro 20w50 HD.  Oil consumption is not excessive, no smoke on start up or on the over-run.  The next oil change is less than 1000 miles from now.  I was riding it the other day in triple digit temps around town and it shifted smoothly and selecting neutral was as it should be.  Clutch action was smooth.  Based on years of experience now with that Spectro oil, I know that will still be the case at the 3000 mile mark.  There are times when I change the oil that I think I could have let it go longer based on observable performance of the bike.  But I don't.  I don't go to any special attempts to get more oil out at the change.  I definitely will not spin the starter to empty the pump.  Very unnecessary and I think counterproductive.  I don't recommend my procedure to anybody, this is just information.  Would other oil do as well as the Spectro?  Very possible, but since I know what works, I won't change unless Spectro HD becomes unavailable.  I believe, as Hondaman has said, a big factor in these engines longevity is regular use.

[PeWe]

Spectro HD is in my K2, still feels good after 3000km.
4500-5000km is my goal.

The sellers have increased the price by +50% since Sept 2021 when I ordered 4 gallons for a relatively good price.

I have oils znd filters for a few years to come. Investment. It will not be cheaper.