Older Guzzis and synthetic oil

Wrigsby1

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Hi experts... I have my newly acquired 40k 850 T5 and want to replace the oil... I work in an autoparts store and we have Silkolene bike oils including 10-50 fully synth "V Twin" oil... It seems a fine enough choice unless someone can tell me good reasons why old Guzzi's don't like fully synth...

Price isn't an issue as I can get it for a very good price... We have 20-50 and 10-40 as well...

Ta in advance...
 
I have just picked up a 1975 T3 Cali. It's a tractor engine and fully synthetic is wasted on it. Whats wrong with 20w50 mineral oil a la BMW airheads and other simple aircooled engines from the same era?
 
I have just picked up a 1975 T3 Cali. It's a tractor engine and fully synthetic is wasted on it. Whats wrong with 20w50 mineral oil a la BMW airheads and other simple aircooled engines from the same era?
I've just used Halfords 20/50 classic
 
a very knowledgable person in the guzzi world told me that synthetic was best for guzzis in case they got very hot, not being regulated by water cooling.

he was involved in top level big twin racing though, and i've never seen or heard of any cause for worry using 20w50 mineral oil, which i what i use.
 
Lets face it, modern Guzzis are spec'd with fully synth oil and the engines have not really changed bar the power output. So all though I just use Silkolene V-TWIN 10W-40 High Performance Semi Synthetic Motorcycle Engine Oil For V-Twin Designs on my V11 sport, fully synth should'nt do any harm. Unless it drinks it like my old GS TC did......
 
i've never seen or heard of any cause for worry using 20w50 mineral oil, which i what i use.

Me too! :thumb2

images
 
guzzi oils

here is what guzziology has to say about oils - if you don't have a copy of this book then get one, it is exspensive but it is very good value for money, please note, hydraulic tappet engines need different oil to "normal" guzzi engines
 
here are some comments about systhetic oils

Here is what guzziology says about synthetics, again I would comment that guzziology is full of information, it is definatley not a workshop manual, but is is full of the years experiance of Guzzi mechanic Dave Richardson.
 
What was the engine designed to use? 20w50 mineral. (SAE Sf - Sj I would guess?)

So use that and change the oil and filter more often.
 
Thanks for the replies... The manual does mention 10-50 mineral and I know most people will use 20-50... One of the side issues with being "sub arctic" is that oil doesn't warm a quick as with you guys in the tropics... My 11GS used to run 10-40 as it emulsified on 20-50 over a period of time... Jeez it even could do it with 10-40 and my K11's were a mare to keep the starter clutch from gumming up...

I was going to mention the weather bit in the thread opener but jeeez... It's hard to start an oil related thread and keep it to "them that know"...:D

It was mainly to see if there were any issues to do with the build materials and synthetic as you get on some older engines... If it burns it I will know if its "overly"...:thumb TBH its twice the price of not a lot to me cost wise...:D

Tanksenoo...
 
In my previous post it mentions a court case (mobil 1 V Castrol) below is a link to the out come of that case, it ia a long read but in summary Mobil 1 won
http://forums.tdiclub.com/showthread.php?t=144822

Also here is a link to what Opie oils say about synthetic oils
https://www.opieoils.co.uk/pdfs/Beware-of-the-labelling.pdf

Niether say much about which are the best to use in your bike,but provide good background information - so that we can spout shite based on fact and not just opinion:blagblah

i sometimes find "fact" to be somewhat overrated :D
 
Am I correct in thinking that Guzzis, like BMWs, have dry clutches? If so, you don't need motorcycle oil, which is formulated for wet clutches.

A good car oil, of the correct viscosity and API rating will be best. The advantage of synthetic oil is that it lasts longer between changes (12,000 miles). A good additive package - any reputable brand has this - is what protects your engine. Cheap oil is often recycled and has the minimum additives needed to meet the API spec.
 
synthetic oils are better at extreme pressure loading and other high load high wear points than dino oils - simple facts.

if you can get it cheaper use it - i would leave it in for 2 intervals and change the filter twice in that time - the oil lasts but the filters don't.

The manuals say to use the best oil available at the time the engine is designed and marketed - 20/50 SG or SF or 10 /40 being the ones then - now its synth oil.

its a no brainer with no clutch to worry about getting oily.
 
My 78 LM2 leaks from the alternator seal with synthetic. Doesn't with standard 20/50.
Guess which I use!
 
.............

if you can get it cheaper use it - i would leave it in for 2 intervals and change the filter twice in that time - the oil lasts but the filters don't.

...........

And just how would you do that on a Guzzi unless it had an external filter conversion? :D

Andres
 
And just how would you do that on a Guzzi unless it had an external filter conversion? :D

Andres

drain into a clean pan and re-fill ? :augie

if you were paying full retail for the longer life properties, i'd do this - cos the filter will clog up with fuel byproducts and shite long before the oil is worn out.
- guzzi filters are minute - but you know that..

if you were getting it half price, maybe i'd put new in.. :)
 
i reckon you'd need to fill the sump with toothpaste to do any serious wear in normal use.

the miles most of these bikes do, just chuck in some 20w50 when the oil loses it's nice golden colour and change the filter every year or two.

pre T3 they never even had proper filters and they go on for ages. the chrome always falls off the bores though, but i don't think that has much to do with what oil is used. it seems too come off above the rings first.
 


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