Mobil 1 20W50 V-Twin with 8.5% BG MOA EL

Jack15T

VIP MEMBER
Joined
Nov 19, 2023
Messages
2
Country flag
Hey Folks, I read Jim Comstock's oil analysis post. Thank you Jim. Jim doesn't mention if

Mobil 1 20W50 V-Twin with 8.5% BG MOA EL is safe for wet clutches. Mobil 1 without the BG additive seems to be okay for wet clutches but not sure about with the BG additive. I would appreciate any info. Cheers, Jack​

 
My recollection is that the best clutch friendly oil on Jim’s test was the bell ray v twin synthetic.

However Jim wasn’t testing for optimal clutch / primary use.

Bel ray sport transmission fluid is designed exactly for that.
 
I have looked up Bel ray and there are different types of its sports transmission fluids.
Has anyone figured out which one is the best at not gumming up our clutch discs?
(I have surflex)


Thanks
Dennis
Vancouver
 
DennisMo said:
I have looked up Bel ray and there are different types of its sports transmission fluids.
Has anyone figured out which one is the best at not gumming up our clutch discs?
(I have surflex)


Thanks
Dennis
Vancouver
Click to expand...
You want the one designed for Harley Sportsters. Good in the gearbox too.

www.ebay.co.uk

BEL-RAY V-Twin Sport Transmisson Fluid Transmission Oil 80W90 1Liter Bottle | eBay

Bel-Ray V-Twin Sport Transmission Fluid gear oil 80W90 1 liter bottle Motorcycle parts - easy - fast - online Air Filters & Air Filter Accessories Engine, radiator & frame protection Workshop requirements, resources Bel-Ray V-Twin Sport Transmission Fluid gear oil 80W90 1 liter bottle V-Twin...
www.ebay.co.uk
 
I have decided to go with Mobil-1 20-50 for my MK-III engine and primary with hydraulic tensioner, since it's pretty good and readily available.

The Mobil-1 I'm finding is API-SJ and says it's good for bikes that require SH, SG, CF as well. The bottles also say reccomended for Harley Davidson V-Twins.

I know Mobil-1 20-50 is one of the top rated engine oils from Jim Comstocks list, but I think things may change, or there could be variations.

Do I have the right Mobil-1 For my engine, and will it also work well in my MK-III primary?

Thanks,
Ed
 
Edfury828 said:
I have decided to go with Mobil-1 20-50 for my MK-III engine and primary with hydraulic tensioner, since it's pretty good and readily available.

The Mobil-1 I'm finding is API-SJ and says it's good for bikes that require SH, SG, CF as well. The bottles also say reccomended for Harley Davidson V-Twins.

I know Mobil-1 20-50 is one of the top rated engine oils from Jim Comstocks list, but I think things may change, or there could be variations.

Do I have the right Mobil-1 For my engine, and will it also work well in my MK-III primary?

Thanks,
Ed
Click to expand...
I would stick with ATF for the primary and change it every time you change the motor oil to save the sprag clutch. GM/Dexron will give you a smoother takeup while Ford type reduces slippage. There is a seal available for the clutch pushrod that keeps gear oil out of the clutch. Get one. Gear oil is a primary contributor to gummy clutches that both drag and slip. Also don't park on the side stand for prolonged periods; that also contributes to gear oil running into the clutch.

You do realize that Harleys have roller tappets and Commandos do not. I do not know if Mobil 1 has enough zinc/ZDDP etc. to lube flat tappets.

MkIII engines had a reputation for flattening camshafts in less than 20K miles. There were also those soft cams in the spares supply for years after last MkIII production. I have had two teardowns for cams on my MKIII before I installed a known good work-hardened cam. No trouble in many years and miles since but I use a ZDDP additive and Castrol GTX which is supposed to have enough zinc anyway. That's also what I use in my Atlas that has the original cam.
 
You want the Mobil1 20-50 V-Twin oil. Do not use this in your primary! Your tensioner will not work correctly
and the chain will slap against the side of the primary case. Use ATF Type F. Lots of threads on this forum
on this topic.
 
L.A.B. said:
I've used ATF in my Mk3's primary and found it to be no good for the tensioner. I prefer 20w/50 engine oil.
Click to expand...
You caught me in a moment of dyslexia whereby I wrote the opposite of what I was thinking.
Good that you are on top of correcting spurious information being spewed by old gents.
 
Thomasa said:
I would stick with ATF for the primary and change it every time you change the motor oil to save the sprag clutch. GM/Dexron will give you a smoother takeup while Ford type reduces slippage. There is a seal available for the clutch pushrod that keeps gear oil out of the clutch. Get one. Gear oil is a primary contributor to gummy clutches that both drag and slip. Also don't park on the side stand for prolonged periods; that also contributes to gear oil running into the clutch.

You do realize that Harleys have roller tappets and Commandos do not. I do not know if Mobil 1 has enough zinc/ZDDP etc. to lube flat tappets.

MkIII engines had a reputation for flattening camshafts in less than 20K miles. There were also those soft cams in the spares supply for years after last MkIII production. I have had two teardowns for cams on my MKIII before I installed a known good work-hardened cam. No trouble in many years and miles since but I use a ZDDP additive and Castrol GTX which is supposed to have enough zinc anyway. That's also what I use in my Atlas that has the original cam.
Click to expand...
Are you using regular Castrol GTX 20/50 or the Classic type?
Regular GTX has had much of its ZDDP removed. It is now down around 800 ppm ZDDP which is OK for modern engines but not great for our old bikes. These numbers change quite often and generally the ZDDP goes down, unless the oil is specific to old engines.
The GTX Classic is made for this and has about 1400 ppm ZDDP.
In wear testing oil analysis showed 80ppm metal with standard GTX 20/50
GTX Classic 20/50 went thru the sane test and showed just 30 ppm metal!
Vr1 20/50 Conventional racing oil was even better at 22 ppm metal. Vr1 chemical makeup was changed last year to make the ZDDP work better. It offered good protection before but is even better now.

Glen
 
Last edited:
Fast Eddie said:
I don’t think that’s strictly true, without the additive it was quite a way down the lists.

The results are here, and worth saving for future reference:

What is the best oil for a Norton Commando?

Norton Commando Motorcycle Oil Tests by Jim Comstock.
www.accessnorton.com
Click to expand...
And it was only the Vtwin version that made it to the ok to use category.
The regular Mobil 1 did not offer much protection at all. It placed right near the bottom in 65th position out of about 75 oils.
 
Fast Eddie said:
I don’t think that’s strictly true, without the additive it was quite a way down the lists.

The results are here, and worth saving for future reference:

What is the best oil for a Norton Commando?

Norton Commando Motorcycle Oil Tests by Jim Comstock.
www.accessnorton.com
Click to expand...
Thanks for the correction Fast Eddie! I am seeing now that you are right. I will have to scrutinize Jim's test results more closely. No problem returning the oil I bought, then I'll just have try again! Personally, I find it all a bit confusing. All I want is for my stock Norton to run dependably.

Thomasa, The engine has a pretty new "rebuild" from the PO, with a new stock cam from Andover Norton. Btw, my goal is to make it to the NWNO ride and camp out in Winthrop this June. There and back again, that is (from Seattle)!

On the primary oil, I'm with L.A.B., the hydraulic tensioner likes 20-50. Maybe as long as you choose an oil that's good for wet clutches, it will be fine? This Mobil-1 says it is. And my take on the clutches is they work best dry, but inevitably get oily. Keep the gear oil out, and they will be fine with periodic cleaning.

I have the push rod seal nut and new clutches. I don't expect that I'll be riding a lot of miles with my new old Norton just yet. Maybe more as I get used to it? At this point, I'm OK with tearing down the primary, once a year or so and cleaning everything including the clutches. Or, as needed.

Right now I'm just trying to get her together for my first Spring ride!
 
L.A.B. said:
I've used ATF in my Mk3's primary and found it to be no good for the tensioner. I prefer 20w/50 engine oil.
Click to expand...
Exactly the same. Even with the tensioner gasket faces checked and a new gasket, I heard my primary chain on the case when I revved it. For the last 3,500+ miles I've use the Belray primary oil. I replace it every service, but I've not needed to touch the clutch since I took the ATF out.
 
Last edited:
Fast Eddie said:
You want the one designed for Harley Sportsters. Good in the gearbox too.

www.ebay.co.uk

BEL-RAY V-Twin Sport Transmisson Fluid Transmission Oil 80W90 1Liter Bottle | eBay

Bel-Ray V-Twin Sport Transmission Fluid gear oil 80W90 1 liter bottle Motorcycle parts - easy - fast - online Air Filters & Air Filter Accessories Engine, radiator & frame protection Workshop requirements, resources Bel-Ray V-Twin Sport Transmission Fluid gear oil 80W90 1 liter bottle V-Twin...
www.ebay.co.uk
Click to expand...
I am impressed by your opinion on this Bel Ray primary oil Fast Eddie! The big question is... how does it work with the MK III hyd. chain tensioner? Any idea if it's 20-50?

Thanks,
Ed
 
Edfury828 said:
I am impressed by your opinion on this Bel Ray primary oil Fast Eddie! The big question is... how does it work with the MK III hyd. chain tensioner? Any idea if it's 20-50?

Thanks,
Ed
Click to expand...
Sorry Ed, I can’t help with that aspect.

My understanding is that ATF doesn’t work cos it’s too thin, which would lead me to guess that the Bel-Ray should be fine. But I am only guessing…
 
Atf works OK in my MK3 primary. The chain hasnt ever marked the cases and it runs quietly.
I use type F, not sure if that makes any difference.
When I bought the bike in 2003 neutral selection was quite difficult. After a year or so of enduring this, a club member suggested that switching to type F ATF in the primary could reduce that slight clutch drag that can make neutral selection difficult.
I drained the 30 weight motor oil from the primary and replaced it with type F ATF. After about a day or two of riding the neutral selection became very easy and has remained so ever since.

Glen
 
Last edited:
Fast Eddie said:
Sorry Ed, I can’t help with that aspect.

My understanding is that ATF doesn’t work cos it’s too thin, which would lead me to guess that the Bel-Ray should be fine. But I am only guessing…
Click to expand...
I did see in an ad for the Bel Ray Sport that it is 80-90W. The reason I asked if it was 20-50 is I'm thinking constancy or thickness may be what dictates the functionality of the tensioner.

I have heard that ATF is basically 10W which, I am speculating the "thin-⁷ness" of is what causes problems for at least some people with the hydraulic tensioner. So, with that line of reasoning, at least the Bel Ray Sport is not likely to be too thin.

Does the Bel Ray seem to you to be a very thick gear oil, or since it seems to be unique, could it have a 20-50 like (or less) consistancy? I like that it keeps everything so clean in the primary, so I'm hoping it could work.

Thanks for your input too Glenn. It is interesting that the ATF does work in some MK III's!

My concern is that being new to Nortons and with my ears not being what they used to be either, if I get chain slap I will know it?

As I'm just getting mine out on the road, I'm trying to be conservative and start with a simple and dependable Norton. Once I become more intimate (lol) with it, then make changes if needed.
 
You must log in or register to reply here.
Back
Top