High oil consumption

The bike is a 73 Tiger that I have owned for 26 years. I had the engine and gearbox overhauled by a reputable shop, the full box and dice you might say. I ran the thing in as instructed and after 1500 k's the thing was using 150mls per 100 k's, so took it back and was told the bores were glazed so a quick hone with new rings etc etc. The running instructions were the same as previously and I faithfully did as instructed but once again after 1500 k's it was still using the same amount of oil.
I sort of thought to myself it wasn't glazed bores so off to another Brit specialist who diagnosed the crappy one piece oil ring that had been fitted, so repeat the above procedure i.e. a hone with " decent rings " and identical run in instructions and off you go. This fellow suggested new guides and valves and they were replaced. Well the bike has run like the proverbial Swiss watch ever since the first overhaul and after the third set of rings nothing had changed much to my chagrin.
So now I know it is not glazed bores or inferior rings so I start to fiddle with it and find 500 mls in the sump, drain it out and run it for an hour and there you go still 500 mls in the sump. The man from Morgo sells me a pump and that is the end the 500 mls in the sump, back to normal, so my question is if there had been that amount of oil in the sump the whole time i.e. from the first rebuild, would that have prevented the run in procedure from being effective??
Some extra information is that the tips of the exhaust pipes are wet and sticky and have been since day one after the first attempt yet the plugs have never looked oily, in fact they are the same plugs from the start. The thing runs beautifully right from idle to red line. The guides have been replaced twice as have the valves. The washers under the head bolts upgraded and the divots there were not too bad. I use the same oil always, Penrite 20/50. The only oil leak is from the exhaust pushrod tube and this only lasts for the first ten minutes and then stops.
I have run out of ideas so any suggestions much appreciated and sorry for the rather lengthy post. Cheers.

So has it stopped burning oil?

The old oil pump can often be fixed for free.

How do you ride it?

Part of the running in process is to ensure ENOUGH revs, not only to limit them.

It may simply need a sound thrashing to get everything nicely bedded in.

Yes what running-in “instructions” were followed?

Forgive me if I’ve got this wrong, but isn’t 150ml per 100km rather close to 240 miles per pint? Which, if I recall correctly, was considered ‘normal’ when new...

Thanks for the quick replies gents, one thing I forgot to mention was that it does not blow any smoke. So some answers,
TT, no it still uses the amount of oil quoted and as for the pump I just got a new one ( and it stopped the 500 mls in the sump ).
I was told to never let it idle for extended periods ( traffic ) and to vary the engine speed ( don't just sit on the highway at the same speed ) and to let the gearbox do the work i.e. don't lug the engine and work up to the red line towards the end of the run in. I changed the oil several times along the way and torqued the head a couple of times.
Fast Eddie, have tried a couple of good thrashings but no change and the thing that is puzzling is that the oil appears to being spat out the exhaust as opposed to being burnt, I have a 650 with unknown milage that does not use a drop. I have also successfully run in a couple of other engines from the same Brit whizz with no problem at all so. Cheers.

If there’s oil in the exhaust that hasn’t been burnt then one would assume it hasn’t been in the combustion chamber.

So, oil coming down the exhaust valve guide, or perhaps down the outside of the valve guide comes to mind as possible causes.

Fast Eddie, your arithmetic is good!! That consumption may well have been stated as "normal" but it is the fact that it is spitting it out the pipes that is perplexing and I have spent a small fortune on it.

Tiger Shark - following on from Fast Eddie's post, whip off the exhaust headers, stick your finger into the exhaust ports and feel for the valves, or use a torch to have a look see. If it's damp in there, it would be a fair indication that oil is leaking past the exhaust valve stem or between the outside diameter of the valve guide and its bore in the cylinder head.

Tiger, whilst you’ve got the pipes off (as suggested by Dave) if you can’t see anything wrong, clean them out thoroughly before re trying, or even try another set if possible.
Oil from a previous issue can easily hang around in baffles and wadding for a long time and continue to display the old symptoms and have you chasing your arse.
Don’t ask me how I know this !!

Triumph 750 bores are not exactly round when the head is torqued down..If the bores were finished correctly ,the rings should seat reasonably well in minutes....Three piece oil rings seem to work better...Do the spark plug insulators or the inside of the shell show deposits from oil usage?

When Noah was a Boy , a quick TAP with a punch ( round head ) or drift ( bar )
on the oil pump balls ,
got them ' seated ' .

A inspection to see if you have grotty balls , or the seats are pitted , might be in order .

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If the oil lines are 5.000 years old , they could be not quite right inside .

A Blow Through with a Air Compressor , on the entire return system , individually ,
could be in order . Insopecting the insides of the osses .

Could even just be a kink in the return line ,
see the rocker diversions not wong .

re reading it , could be looseish / leaking Ex Valve Guides . Maybe .

Thanks for the replies gents, am having butt frozen in Ireland and will be back on it when back home in a week or so. Thanks for the interest shown in my on going problem. Cheers.

Gents, sorry about the delay but this is the D/S exhaust port.

That doesn’t look good. Probably head and barrels off time.

Before you do though, I notice the rocker box gasket leak... you sure you’ve not got too much oil up there? And or that the engine is breathing properly?

Fast Eddie, took the inspection cover off and looked inside and no puddles of oil. I previously connected the D shaped breather tube to a jar of water and it blew bubbles when the engine ran so I guess it’s ok. There is no oil coming out that breather. The plot thickens. I will post a pic
of the valves and guides that came out of it in the morning and the plug from that side too. It is driving me around the bend.

Here are the exhaust guides and valves that were replaced, the guide on the right has little punch marks?? The other one looks like it has been hammered out of the head.

Tiger Shark said:

View attachment 8064 Here are the exhaust guides and valves that were replaced, the guide on the right has little punch marks?? The other one looks like it has been hammered out of the head.

Click to expand...

Any more news on this? I'm interested because my Tiger 750 uses too much oil (about 1ml per mile - I know some say this is 'normal' but to me it shouldn't be. I've had other 750 Triumph twins that have hardly used any).

Those punch marks on the guide suggest that whoever fitted them found it was loose and instead of doing a proper fix, made it "fit" using this incredible bodge. It will have damaged the bore in the head too, and will almost certainly have let excessive oil down around the guide/head interface.

Are you satisfied that this was the cause of the oil drinking? And have you spoken to whoever fitted that guide?

Thanks Tigernut, short answer is no there is no development as yet, been to busy with work and we have just had the hottest summer on record and my garage is like a sauna (great in winter) so have collected the parts to do the job just need all the stars to line up. The chap who did the "bodge" denies it, he has since stopped doing mechanical work. I intend to do it myself and am resigned to top end overhaul and back to standard bore(Aerco) with new pistons (JCC) and rings (Goetze). There is no rush as I mentioned the machine runs really well other than the oil consumption, in fact I off to work on it right now. Cheers.