High oil consumption

Yeah, as has already been said, that guide was centre punched because it was loose in the head. So, unless an over sized guide has subsequently been fitted, and the guide bore machined to suit... you will most likely still have a loose guide... and that’s highly likely to be where the oil is getting ‘through’.

BTW, oil getting down the outside of the guide was suggested back in post #7.

But I’m with you, if the bike is running well... ride it. Save the rebuild for a rainy day !
 
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Thanks FE, do not disagree with the consensus that exhaust guides are the most likely culprit, the bore is already +60 and has been honed three times throughout the course of this saga so I am thinking while the head is off might as well do the pistons and rings. Might just go a new head and be done with it??
 
Based on my recent experience, if it’s burning a bit more oil than it should, don’t use fancy iridium plugs, they’ll foul up, causing poor running and lead you to chase your tail looking for none existent ign system and / or carb issues.

My personal advice would be to use Champions.
 
Fast Eddie said:
Based on my recent experience, if it’s burning a bit more oil than it should, don’t use fancy iridium plugs, they’ll foul up, causing poor running and lead you to chase your tail looking for none existent ign system and / or carb issues.

My personal advice would be to use Champions.
Click to expand...

I concur!
 
Tiger Shark - "off with its head"! A loose valve guide isn't the end of the world - if you discover that is the problem. Get your friendly local machinist to make you an oversize guide and while he's at it, get the bore of the guide honed.
 
Kibblewhite do nice Triumph valve gear.

I bought their 6mm stemmed jobs with 1.5mm oversized inlet valves.

And their oversized OD guides, my thinking being that they can be turned down to a perfect fit.

They’re all still in the box at the moment tho...
 
daveh, when I get around to it I shall start with the exhaust guides!! I am still looking around for a shop to send it to, they are no longer in every suburb. The damn thing goes so well I am reluctant to fiddle with it but it's thirst for oil annoys me but that is probably because I have thrown a fistful of fun coupons at it!!
FE, indeed I shall only use quality replacement parts as I would like this bike to outlast me. Cheers.
 
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...

There must be more to that story with oversize guides available to + 0.025", you would (well I would) have to be curious to the OD of that guide and what is in there now.
 
Kibblewhite valves and guides worked well in my 2 A65 heads and work in my T150V now.
Very much recommended.
Goetze rings are also a good move, finish is arm and a leg above average stuff sold as "Hepolite".
 
Kibblewhite guides in over size OD only go to +0.015" which should be enough but if you want bigger as I found out after asking, will cost you US$400. (minimum charge) ... (If you had to have Kibblewhite)

Edited to be more precise.
 
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You can oversize a guide by copper plating the OD using copper sulphate. Fill the ID with blu tak or wax so the bore stays copper free.
 
Time Warp said:
Kibblewhite guides in over size OD only go to +0.015" which should be enough but if you want bigger as I found out after asking, you want bigger and that guide will cost you US$400. (minimum charge)
Click to expand...

If you have to go big you could look at using 850 Commando guides and having them sized to what ever you want.
 
That was just a generiastion regarding the Kibblewhite and UK made guides for the T140.... the UK ones as posted go up to + 0.025" for those folk who like to bash guides out cold where as the Kibblewhite do not.

Copper build up would not be acceptable to me, in my case I found what I needed in Germany.
 
Thanks gents, I have found a shop that can be trusted with the head so when I get the time off it comes!! I will be more than just a little interested in the guide bore dimensions (exhaust) as it seems that this might be the problem, and, reporting back here prior to putting it back together. Cheers.
 
High oil consumption
High oil consumption
The head is off, what do you think??
 
Ouch! You shudda felt and / or heard this?

Pistons have been hammering into the head. Hope you’ve not buggered your crank n rods.

Someone must have skimmed the head / barrel / cases ‘enthusiastically’ in the past. Either that or your big ends are shot... or you’re crank is broke... allowing the pistons to travel too far upwards (unlikely really).

The head will clean up with some emery, unless you know someone handy with a mill.

Barrels need to come off, I’d change the pistons as a matter of course.

Check the rods by getting a piece of bar turned down to be a nice fit through the little ends, it should fit nicely through both rods if they’re straight.

Check the big ends for play.

Upon re-assembly check the piston to head clearance with soft solder or plasticine or similar, you need at least 1mm (0.040”) use a thicker head gasket or base plate to achieve this.
 
FE, I have cleaned the carbon off the crown of one piston and it has no untoward marks on it so I guess it is the poor light that has made what appears to be dings. The inlet ports are full of carbon as well and the timing side inlet valve is wet with oil. I am sending it off after Easter to a shop 800 klm’s down the road so probably no progress for a while ( unless I decide to get a new head ). Two shops have had this engine and it is still not right, ummm I might be just a little more than p****d off at the moment. Is it really that difficult??
 
It's becoming more and more difficult to find a machinist knowing about brit bikes and doing decent work.
I keep mine in high esteem, never argue about prices or time frame my parts are ready.
His work is top notch, so my part is to prepare parts and time frame to be ready with everything before spring.
 
Ok folks we have some progress but still some questions. The barrel is good other than glazed, the bore is correct for plus 60 and the taper .0005 ins. and there is no ridge at the top so he says with a light hone and new rings it is serviceable. The drive side exhaust valve had to be removed via small hammer and soft drift and the other side needed as much force as your thumb could take. Old mate didn’t believe the bike was actually running, he mumbled something about “reaming”. More to come.
 

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