Hitchcocks Forum

Help!having very recently purchased my 4000km iron barrel 5 speed electric start 2003 Sixty 5 as with all bikes new to me I want to change the oils and filter.But to what is the Question there is so much conflicting advice. I intended to use Morris 20/50 ring free as its good quality and easily available from my local bike shop. I used it for several years doing high mileages in my old BMW R850R which seemed to 'like it' & with no problems.

The primary Case is an unusual one every thing from automatic transmission fluid to 20/40 or 20/50 as an electric start (I am using the kick start and decompresser to switch off to hopefully prolong its Usefulness for junction stalls as per advice here) I was going to use some of the 20/50 I would use in the Engine? I was going to put in 420ml or until it comes out the level plug but apparently some US/UK bulleters use a liter in there as allegedly it prolongs sprag clutch life? Cant see how that would make a difference as long as there is a thin film of oil on it but others may know better?

Finally 5 sped gearbox oil, the book I have says EP90 which I assume is a straight Extreme pressure oil and not a Hypoid 90 which I think can eat bronze bushes (I used to have a Ural and they cant use it either because of this problem)I assume a Bullet has bronze bushes also?
Advice gratefully received

Oh blimey, here we go again.
As you say Mr Grumpy, there is a lot of conflicting advice, on this board as well as elsewhere. I'm afraid the answers to your question will be just that.

My 2 pennyworth is:
Any 20/50 - cheap as you can get it and changed @ 1500 miles.
ATF in the chaincase as I believe it helps stop the clutch gumming up.
EP 90 for the 5 speed gearbox.
ATF in the forks as it seems to be about the right viscosity (and if you use it in the chaincase you'll have it handy)

I don't believe you need to overfill the chaincase as there should be plenty for the sprag. It's not lack of lube that busts sprags.
Be aware that quite a lot of oil is left in the timing case when you drain the engine so don't just go pouring in the full amount quoted in the book.

Engine oil in the gearbox not gear oil, just think about it every unit construction engine ever built runs engine oil in the gearbox including the UCE Enfields

As Pete says, be aware of the amount of oil left in the timing case. Just refill a bit at a time, checking dip stick as you go.

Thanks Pete F I appreciate the advice also thanks Norm and Wilf for your input.

Synthetic oil is recommended if used in an engine/ gearbox arrangment, it can withstand the mulching action of the gear teeth much better.

5 speed gearbox is separate unit, use EP90

How does so much oil get 'hidden' in the timing case? And how does one drain it? I can't see the point in changing the oil if you can't get all the old stuff out. There must be some way of draining it back to the sump..?? After all, oil is supposed to circulate.


Or does one have to remove the timing case? If so, how does one fill it again?

All seems a bit naff...

Thanks Leon thats what I use in my unit 1200 bandit that and I like to Tour abroad and its more heat stable.
Neddy I am going to use a straight EP90 which would seem to have fewer additives and change it often . I dont know what Bullet 5 speed gearbox bushes are are made off but if Phosphor Bronze which would seem possible but maybe Royal Enfield have used something else in the 'new' gearbox, there used to be an issue with Hypoid oils I remember from my Ural days? I did a quick trawl on line to see if I remembered it correctly and this came up on the AJS and Matchless site.
'Do not use EP or Hypoid oils in gearboxes with phosphor - bronze bushes. The oils contain an additive which reacts with the phosphor bronze and eats it away. This information has been confirmed by Castrol in Melbourne.'But then it goes on about regular oil changes should stop this happening.Yet another spanner in the oil debate and once again back to you pays your money and makes your choice!!There are several articals on it if you put Phosphor Bronze bushes and Hypoid oils in your browser.

Exile, Oil circulation on the classic engines is;
From "tank" via feed pump to big end and then splashes barrel, mains etc as it falls to the sump.
From sump it goes via the scavenge pump to the rockers (all of it, unlike most designs of the period)
Returns to timing chest down the pushrod tubes but the level of the oil has to get above the level in the "tank" before it overflows into the "tank" (not pumped back)
I suppose it's like this as the RE has this odd "tank" integral with the engine instead of being remove like most others.
The rockers don't need all that oil of course but it also serves to keep the head cooler.
To drain (most of) the oil from the timing chest, remove quill bolt and catch oil as it drains (big bolt in side of cover). There's no need to get the last bit out by removing the timing cover, but that is a good idea occasionally to inspect the oil pump drive worm. This can wear or be damaged as it's not designed to go backwards so kick-back can damage it. Mr H makes a better one if you're bothered.
There's no need to refill the timing chest as it will refill with normal circulation but the oil level in the tank will drop until it reaches it's proper level.