Triumphrat

T140VSIMON · 09-12-2009, 07:30 AM

Hi To All.

I would like some help if poss!

I have a 1978 T140V, yesterday while out and about i covered 20 miles, the engine was warm and she started pinking at mid revs, then i noticed some smoke from the right hand exhaust on tick over, after cooling down she rode fine until hot and again the same happened.

I use 95 octane unleaded fuel with Castrol adertive, i have a small oil leak from the lower part of the front push rod tube, for info.

Any ideas would be good and thank you for reading.

Kind regards Simon.

Plewsy · 09-12-2009, 08:00 AM

Hi T140VSIMON,

You should look for 97-98 octane I find BP Ultimate about the best.
To run on modern 95 oct you will have to retard your timing a few degrees.
How long is it since its had a decoke and new rings?
To fix the pushrod tube leak you will have to remove the head.

Beemie · 09-12-2009, 07:46 PM

My 76 manual states minimum 97 octane.
The bike never ran well on anything less than Sunoco 260.
It might have squeeked by on Mobil Super in a squeeze, but forget Gulf No-Nox or anything else, and those were all high octance mixes of the distant past. Can't buy any of those now.

So now I use Sunoco Standard Racing Fuel (110 octane} mixed woth 93 pump gas.

I don't understand people saying that they can run straight pump gas.

Ping, ping, ping......

By the way, I was told by an octane booster manufacturer that they gave it up because gasoline mixtures change so much that the booster couldn't work without constant adjustments.

daveforty · 09-13-2009, 05:30 AM

I have been using 'super' unleaded in my T140E recently and it is running well, possibly better than it was on old fashioned four star in it's last years of availability.

RetroRod · 09-13-2009, 05:42 AM

Hi Simon,

This is interesting.

There is no doubt in my mind that you need to be on high octane gas, the higher the better. I do not disagree with Beemie's post, though racing fuel is not always available, or convenient to use.

I know some Bonneville owners who run their bikes on 95 octane say they run well, but "running well" is a very subjective term. What they think is OK, may seem terrible to me.

You give no history of the tuning on your bike, and so one assumes it just started pinging out of the blue. You say it pings at mid revs, by this do you mean 3500rpm or something different?

Pinging is also a symptom of advanced timing, and without you giving a brief about the tuning history, all you will get is educated guesses. These may or may not be on the mark.

Why don't you post a little more info about the age of the engine, the ignition you run, the tuning details of the carbies, and you just might get an answer that fixes the problem. RR

T140VSIMON · 09-13-2009, 07:15 AM

Dear RetroRod, Daveforty,Beemie and Plewsy,

History of the bike, i bought her last September, spent the winter completly ripping apart and finished the rebiuld around March, i fitted a boyer mk3, single coil, power box, battery and new wiring.

She started first kick and i have run her like this for most of the summer, "great i thought " until today!

After reading your post's i thought i had better just check the timming, i adjusted it a very small amount, started her up, first kick, i then went for a spin, Oh my word, i now have a different bike, she run's smooth, tick's over evenly, Pull's like a train, no rattles and goes up and down the gears perfect with no jerking.

This been my first British bike i thought thats how they rode, Until now, i am so pleased as it sounds so tight and perfect.

So this winter it will be a head off and replace the push rod seals.

Thank you all very much for your help, i will now be keeping the bike.

Kind regards Simon.

UnmarkedBill · 09-13-2009, 06:14 PM

You weren't gonna keep it?!? Call me next time it pings! haha....

Those pushrod seals are notorious, don't let it keep you up nights. Also, the set screw on the tappet block will give you a greasy pants cuff, keep it tight with a good crush washer.

NickL · 09-14-2009, 03:29 AM

If you want to run lower octane petrol/fuel you will need to retard the timing a few degrees. Also remember that the octane rating falls off with time so don't leave fuel in the tank for months. I run BP Ultimate with a lead substitute successfully in my Morgo T120 at 9.5-1 comp. at 36 degs max advance.