Author Topic: 20/50  (Read 2001 times)

Offline davefirestorm

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20/50
« on: December 18, 2019, 06:32:36 AM »
My new to me 750F came to me with fresh oil and filter,time to change the oil again.Previous owner been running it on 20/50 mineral oil,I don’t have enough 10/40 mineral oil ( find it harder to source these days ) what are your thoughts on grades of oil to use? Apologies for bringing up the subject but it is cold and wet outside😂😂
Honda CB650Z
Honda F6C Valkyrie

Offline Bryanj

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Re: 20/50
« Reply #1 on: December 18, 2019, 07:20:38 AM »
20/50 is a bit thick for uk except very high summer.
Try Tesc for their 10/40 (maybe 15/40) mineral DIESEL oil

Offline K2-K6

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Re: 20/50
« Reply #2 on: December 18, 2019, 09:07:23 AM »
As Bryan says there's usually a match in those oils to the spec required.

Have you noticed Bryan though,  the supermarkets around here have certainly reduced their oil choices availability.  Asda and b+q did quite comprehensive range but all dissapeared over last few years. Huge Tesco here has absolutely minimum choice now,  Eurocarparts locally still have decent choices.

From the viscosity point of view,  Honda's own data states that 20w can be used from 0 degree C ambient upwards. Historically I've used 20/50 alot in these 750s and never had any issues. It's pretty low risk choice,  oil condition having far more impact if not changed.

Offline Trigger

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Re: 20/50
« Reply #3 on: December 18, 2019, 09:37:00 AM »
All oils have changed over the years. Haven't seen anyone since I was a kid lighting a fire under the tank on a truck  :o

Offline bobv7

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Re: 20/50
« Reply #4 on: December 18, 2019, 09:43:36 AM »
I always use 10/40 except for one time in an emergency when I had to put in 20/50. The engine seized a piston so I never did that again. Opie Oil have a good selection and often do club discounts.

https://www.opieoils.co.uk/c-782-10w40-motorcycle-engine-oil.aspx

Offline Mr_Sheene

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20/50
« Reply #5 on: December 18, 2019, 03:39:03 PM »
I usually use Morrison Lubricants (Not the Supermarket). Their website recommends:
1st Choice Race 4 TT 10W-40 - Part No. FTT. 
2nd Choice Race Sport 4 - Part No. SSF.

I usually buy mine in advance at motorcycle shows and autojumbles like Kempton Park but they do sell their oil on-line and have a technical desk if you have any questions.

Offline Moorey

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Re: 20/50
« Reply #6 on: December 18, 2019, 04:02:52 PM »
All oils have changed over the years. Haven't seen anyone since I was a kid lighting a fire under the tank on a truck  :o

 ;D ;D ;D That used to be every winter at 6AM on the pit stack to get the graders and dozers running for the day.

Offline StevieWonder

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Re: 20/50
« Reply #7 on: December 18, 2019, 05:53:40 PM »
I read that mineral oil is best to 'run in' an engine after rebuild. So since mine was rebuilt, it's been running on 'gamma 10W40 mineral motorcycle oil' by ROCK OIL.
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Offline philward

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Re: 20/50
« Reply #8 on: December 18, 2019, 08:24:01 PM »
I use 10/40 now but can't comment on what affect it has on my engines as the bike is used in good conditions and engine totally rebuilt - so I refer back to when I used bikes in all weathers all year round and I used the likes of Duckhams 20/50 on all my Fours (Honda SOHC, ZI and Suzuki 1000's) over 150,000 plus and never had one mechanical issue (can't even remember changing clutch plates - but that might be my memory).
Point is, in my opinion, its about changing with quality oil and filters at the stated service intervals rather than the small differences in grades - and warming bike properly before ragging it.
Just my view
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Offline davefirestorm

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Re: 20/50
« Reply #9 on: December 18, 2019, 08:37:07 PM »
Not going to use it through winter so will change oil/filter now put last of my 10/40 in my Superdream I’m off to Newark show January so hope to get some 10/40 there.Thanks for all opinions on subject :D
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Online Spitfire

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Re: 20/50
« Reply #10 on: December 19, 2019, 09:40:27 AM »
Back in the olden days I always used Duckhams 20:50 on all of my bikes, never had a problem and I used the bike all year round, I did not start driving cars until I was 28 so the bike was used in all weathers, was fun in the snow.

Cheers

Dennis
1976 CB750F

1977 CB750F2 In bits

1964 BSA A65R In bits

Offline bobv7

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Re: 20/50
« Reply #11 on: December 19, 2019, 10:46:52 AM »
The Duckhams Oil Company were the inventors of the 20W50 multigrade oil which meant that motorist now didn't have to use a different oils according to the temperature or time of the year. This blend of oils was a revelation to the British automotive industry as it went a good deal of the way to compensate for the less than exact engineering tolerences and practices of the day. Your average 15 year old Morris Minor or brand new Triumph now sounded quieter for longer. (Still leaked though!) Then along came the Japanese with their clever metric measuring stuff and brand new machinery that didn't require Old Harrys' skills to compensate for clapped out 60 year old bits of kit. New machine tools meant the Japanese could consistantly work to tighter tolerences which naturally allowed for the use of thinner lubricants, hence the switch to grades such as 10W40. A thinner oil equals faster warm up and so less wear from cold start up; less stiction in moving parts so they can be made to move faster and lighter and cheaper. Thicker engine oil was no longer the way to go so the evocative odour of Castrol R became a faded memory where bikers gathered, and a jolly good thing that was too for any motorcycle engine rebuilder.

All this is just my version of the oil question as I hadn't previously come across anyone regularly using or advocating the use of 20W50 oil in any Japanese bike since the 1970's. Obviously there are some that did and still do and if that works for them, excellent, do what works best for you, I say. :D

Offline davefirestorm

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Re: 20/50
« Reply #12 on: December 19, 2019, 11:03:30 AM »
In the winter my Velo single wouldn’t start so I’d have to change to a thinner grade oil also had to drain  sump if left more than couple days because would you believe it it would wetsump it also leaked a lot of oil  ;D
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Online Spitfire

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Re: 20/50
« Reply #13 on: December 19, 2019, 03:46:15 PM »
 Thicker engine oil was no longer the way to go so the evocative odour of Castrol R became a faded memory where bikers gathered, and a jolly good thing that was too for any motorcycle engine rebuilder.

I can well remember putting some Cassie R in the petrol tank of my BSA A65 to get that nice smell.

Cheers

Dennis
1976 CB750F

1977 CB750F2 In bits

1964 BSA A65R In bits

Offline Seamus

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Re: 20/50
« Reply #14 on: December 19, 2019, 06:32:09 PM »
Still have about a litre of R for adding to fuel. Confuses people when I turn up on the 500

 

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