Best oil for a triumph Bonneville t140

[popstar1]

 My bike is currently running very well however when I pull the clutch in from cold there is a hell of a clunk and sometimes it's stalls the bike when starting off from cold , when the engine is hot I simply place at Tie wrap over the clutch lever to keep the clutch free  and to prevent it from sticking , I know this is not a long-term solution and wonder if there is  something on the market that will alleviate the sticking clutch problem as I am finding it difficult to change gear no matter how I adjust the clutch . I have considered changing the oil  in the primary drive side  to a more slippery oil maybe a semi synthetic .

[L.A.B.]

My bike is currently running very well however when I  Paul the clutch in from cold there is a hell of a clunk and sometimes it's stalls the bike when starting off from cold ,

Do you mean a heavy clunk when you actually pull the clutch lever, or do you really mean when you select first gear?

Are you 'freeing the clutch' in the usual way before you start the engine?

 

I know this is not a long-term solution and wonder if there is  something on the market that will alleviate the sticking clutch problem as I am finding it difficult to change gear no matter how I adjust the clutch .

If you are also having difficulty changing gear then it's possible there is a problem with the clutch, possibly the tabs on the plates are worn and/or the slots in the drum or clutch centre have become notched where the tabs rub, pressure plate not lifting squarely or worn lifter mechanism. 

I have considered changing the oil  in the primary drive side  to a more slippery oil maybe a semi synthetic .

The T140 crankcase and primary are not completely separate compartments, so whatever oil you use in the engine also needs to go into the primary case.
If the problem is due to clutch wear then a 'more slippery' oil may not improve matters and you might also end up with clutch slip.

[chaterlea25]

Hi,
+ 1 on worn clutch parts,
T140's are hard on clutches
A useful upgrade is the LP Williams / SRM 7 plate conversion ,and a decent cable

Make sure what ever oil you use is suitable for wet clutches, (car oils are not suitable)
I have had good results (clutch wise ) with SIlkolene (Fuchs) Comp4, 20/50

John

[Rex]

Do you get a clonk when you pull the clutch lever with the engine not running?
If so, the three ball lifting mechanism is over-ramping and the pushrod/cable need (re)setting up.

[popstar1]

 The issue is when I actually engage the gearlever for the first time from cold as soon as the gear lever is depressed the bike lurches forward and cuts out however once I start the machine again  The initial clunk disappears as if the plates have now separated . The action of the clutch and clutch cable is quite smooth if a little heavy by modern standards.  On longer journeys even when the engine is hot changing gear is still quite a  chore  because of the notchy gear lever action .

[mini-me]

Free the clutch before starting it, Us old time Triumph Riders used to put into second before going back down into first to pull away.

A thinner oil in the chaincase might help, a 1/4 pint of auto transmission fluid or even 30 grade tinned with paraffin.

I have known the over keen fill the chaincase right up with oil........ you only need to wet the bottom run of the chain.

Next time you have the chaincase off check that the pressure plate runs true, with the engine running pull the clutch in and  the pressure plate should come to a halt, if it don't it'll drag and bugger the gear change, properly sorted these clutches are as good as any.

I realise you are talking T140, my Triumph experience stopped some years ago when they put the gear change on the wrong side but the generality of the above should still apply.

[L.A.B.]

The issue is when I actually engage the gearlever for the first time from cold as soon as the gear lever is depressed the bike lurches forward and cuts out however once I start the machine again  The initial clunk disappears as if the plates have now separated.

That would appear to be because you are not following the usual British bike ritual of 'freeing the clutch', by pulling the clutch lever and operating the kickstart sharply until the plates separate (ignition and fuel off) before you start the engine.

[L.A.B.]

A thinner oil in the chaincase might help, a 1/4 pint of auto transmission fluid or even 30 grade tinned with paraffin.

I have known the over keen fill the chaincase right up with oil........ you only need to wet the bottom run of the chain.

I realise you are talking T140, my Triumph experience stopped some years ago when they put the gear change on the wrong side but the generality of the above should still apply.

It doesn't.
As I already mentioned, the T140 primary drive and crankcase compartments are connected (twins 1970-on, so well before the gearchange swapped sides) and the primary oil level is maintained automatically, so on no account should anything other than the same oil as the engine be used in the primary case on a standard T140.

[popstar1]

 Okay thank you for all the tips if all else fails I will take the primary chain Case off and examine the actual clutch , back to the original question,which is the best oil for T1 40 I've been told straight 20/50   Others have said 10/40 .

[mini-me]

I stick to my comments L.A.B, and know about the inter-connected case, [been riding/ maintaining Triumphs since 1966]  but so often I have taken off a cover to find the insides full of something that looks like custard; I never liked that  breather set up at all. A bit of thin oil does the job. Afetr all its not in circulation, just on its way out mostly.

Slightly O/T after years of being a Triumph fanatic/ Met Police Mechanic and all,  OIF, The Meridan Co-op and LH gear change did it for me with Triumphs.
I still maintain my brothers TR6 he bought new in 1970; got no time for the new generation of Triumphs, but then I am an old git

[L.A.B.]

back to the original question, which is the best oil for T140 I've been told straight 20/50   Others have said 10/40 .

Ask ten different people that, and you are liable to get ten different answers!

"Straight" oil is monograde (SAE30, SAE40 etc.).

20w/50 is multigrade and personally, I suggest you use 20w/50. My own choice is Morris V-Twin and that's what I use in my T140 as it has adequate ZDDP and is JASO MA, so is suitable for use with the Triumph clutch.

http://www.classic-oils.net/Morris-V-Twin-20w50-Motorcyle-Oil


 

[L.A.B.]

I stick to my comments L.A.B, and know about the inter-connected case, [been riding/ maintaining Triumphs since 1966]  but so often I have taken off a cover to find the insides full of something that looks like custard; I never liked that breather set up at all. A bit of thin oil does the job. Afetr all its not in circulation, just on its way out mostly.

I can't say I agree with your views. Better to change the primary (and engine) oil at the correct intervals, in my opinion. 

[mini-me]

You are quite right about oil changeing LAB, but so many don't. Thats the problem.

[L.A.B.]

You are quite right about oil changeing LAB, but so many don't. Thats the problem.

True in the good old/bad old days more than now I think, as the pendulum definitely seems to have swung the other way.
Our old relics - sorry cherished classics are far more likely to be over-pampered and mollycoddled nowadays with oils changed more regularly than is strictly necessary.