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Discussion Starter #1
My 1979 t140e has been running fine lately so yesterday I had a short ride round to my sisters and all was well,when I started it to come home I noticed it was smoking quite a bit while ticking over and when riding it it was running rough like it was about to run out of fuel and it eventually died on me I got it a petrol station topped it up and restarted it but it was still running rough I got it home and now when I start it it’s smoking quite a bit from the left exhaust so my question is where should I start looking first? It’s typical as I was about to put it up for sale,anyway any ideas or thoughts appreciated..
 

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Discussion Starter #3
I bought it in November 2018 from the guy who imported it from the states where it had been in long term storage so I cleaned filters changed oil new plugs new carb rubbers new brake lines and new Avon tyres and it’s been running fine engine sounded sweet and no smoke although I haven’t done a great deal of mileage,this is the first triumph I’ve had so not sure where to start looking.
 

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Discussion Starter #6
Not checked valves should I? I've always left it on center stand although it's smokey (left side) it doesn't sound rattling and the engine feels tight with plenty of compression when kicking over.
 

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blue smoke or black smoke? as a rule of thumb, blue will be oil burning, black will imply a rich mixture.

(I have never seem my T140 smoke from being on the side stand [lots of other occasions though], although there were times my K75 would leave a smokescreen that a 70s 2-stroke would have been proud of if I left it on the prop stand).
 

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easiest is change the spark plugs for new - or just swap them over to see if the smokey side moves - check if both plugs are sparking
then I would be inclined to strip the carb on the smokey side - mainly cos its relatively easy to do ( stripping both carbs would be an idea )-- if all is OK there - then as GPZ suggests - progress further on a full maintenance check
 

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Hi Sam750, The choke didn't accidently put on did it? Could enricher seal have fractured on left carb?

Is the oil suddenly & oddly low? That might indicate wet sumping while running. Now keep eye on oil level while parked. Does it noticeably drop after sitting a few days, when it didn't used to do that.

While possible, unlikely valve adjustment would suddenly go off. Generally tight valve will gain clearance when hot & often runs better warm than cold. As was stated valve adjustment is part of routine maintenance.

Smoke & poor running may or may not be related. What do spark plugs look like? Obviously oily on left? Or obviously black & sooty. Compare plugs side to side.

If you can get it running good, I suggest going on a very long ride, even if it's circles around your neighborhood. If possible try to take it on open road 60+ mph for 50 miles at least. Rings in storage can rust and coke up. Fast riding will often free them, but takes some miles. Often about 2-300 miles.

I might look at plugs before I got too deep into other repairs. Suddenly sooty plug could point to enricher problem??
Don
 

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Discussion Starter #10
You could be on to something there as I did start a thread recently about sooty plugs and a few replies mentioned enrichers so will remove carbs tomorrow and strip and clean and will also check and keep an eye on the oil..
 

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Discussion Starter #13
So I was in process of cleaning the left side carb when I saw GrandPaulZ’s post I just looked at the oil level and nothing showing on dipstick so I removed the sump plug and drained out exactly 400ml of oil not being familiar with wet sumping is that good or bad? Can I replace the 400ml back into the top of the frame filler or should some/all go back in the sump?
Thanks for the replies..
 

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Not checked valves should I? I've always left it on center stand although it's smokey (left side) it doesn't sound rattling and the engine feels tight with plenty of compression when kicking over.
Worn valve guides are a common problem with these engines. Maybe have those checked out. Anyway, parts are relatively inexpensive and plentiful for these bikes. They are pretty much recyclable.
 

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For our colonial cousins, 13.5 fluid USA fluid oz.
That"'s too much so junk that oil and add fresh to the tank.
Then go for a ride and check. It may drop a bit then should stabilise - if it continues to drop you have a stuck valve in the oil pump. Sometimes it's a bit of grit that will go
 

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So I was in process of cleaning the left side carb when I saw GrandPaulZ’s post I just looked at the oil level and nothing showing on dipstick so I removed the sump plug and drained out exactly 400ml of oil not being familiar with wet sumping is that good or bad? Can I replace the 400ml back into the top of the frame filler or should some/all go back in the sump?
Thanks for the replies..
I would throw away the oil that was drained out, and top up with fresh oil. You cannot be sure the container you drained into was perfectly clean and you dont want to introduce dirt into the oil tank. Oil is cheap.

I have had inlet valve guide wear leading to high oil consumption. There was a time when there were rubber collars at the top of the inlet guides to prevent oil being drawn down into the inlet ports, but I was told this was deleted as the lack of oil going down the inlets made them wear out quicker... my bike (same year as yours) doesnt have inlet oil seals.

While you have the carbs off the bike, take a look down the inlets. If the guides are worn, the back of the valves will probably be oily and sooty.
 

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Can I replace the 400ml back into the top of the frame filler or should some/all go back in the sump?
Yes you can, no need to put any in the sump. I'd try the easy stuff first, pour the oil back into the tank, drain the sump again after a couple of days and measure what comes out. 400ml is a lot in my opinion, the phrase often seen on this forum is 'a cupful' and I interpret that as around 200ml. Excess oil in the sump will be blown out through the breather and/or pumped into the combustion chambers producing smoke so I'd start there before pulling the engine apart.
 

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400ml in the engine and the crank will be touching the oil. That oil then flings up the bore. As said, drain that 400ml then ride it and see if the smoke stops. If, when parked, it starts filling the engine again, its the oil pump letting by. All covered already. If this was a BSA A65 with crankcase oil filled, it would pump most of it out the breather and empty the oil tank. The Triumph will just tend to smoke until you fix the pump.
 

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Discussion Starter #20
Its hard to describe the colour it was more of a whiteish grey colour but while stripping and cleaning the carbs the rubber washer on one of the air screws disintegrated so when I got it all back together it didn’t start on the first kick like usual and when I finally got it started it was running rough! I assume because the air mixture screw isn’t sealing it’s very loose so I’ve ordered two new air screws from Amal and will have to wait for them to arrive before i can go any further, So its on to sorting the charging problems out with the xs650 oh the the joys of classic bike ownership! 😆
 
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