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Discussion Starter · #1 ·
I was about to set the tappets on my '77 T140V after having watched Plewsy's video. Thought I would also read the workshop manual and glad I did.

Amazed to see the difference in settings between a T120 and a T140!

T120 - Inlet 0.002/Exhaust 0.004
T140 - Inlet 0.008/Exhaust 0.006

Why the huge difference???
 

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I was about to set the tappets on my '77 T140V after having watched Plewsy's video. Thought I would also read the workshop manual and glad I did.

Amazed to see the difference in settings between a T120 and a T140!

T120 - Inlet 0.002/Exhaust 0.004
T140 - Inlet 0.008/Exhaust 0.006

Why the huge difference???
Sam,

I'm no expert on this, but it will have something to do with cam duration, The cam specifications determine tappet clearance.

Personally, I run the tappets on my T120 at about .004' IN, .006" EX, as I'm lazy about checking them and If I hear 'em rattling, I feel happy.

Mr Pete is your man for this I think. RR
 

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I was about to set the tappets on my '77 T140V after having watched Plewsy's video. Thought I would also read the workshop manual and glad I did.

Amazed to see the difference in settings between a T120 and a T140!

T120 - Inlet 0.002/Exhaust 0.004
T140 - Inlet 0.008/Exhaust 0.006

Why the huge difference???
Almost exactly with me. I watched the video and have 2 manuals, a Haynes and Triumph, glad I took the time to read, and, reread the manuals, a huge difference.

I have to use the .008 & .006 setting myself, was curious why the intake has a larger clearence.
 

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The inlet has a large clearance because the T140 has a hot inlet cam and a very mild exhaust cam. They did it this way so it would meet the US emission laws and still have some torque.

Swap your exhaust cam for an inlet and once you get it timed and jetted OK it will fly ;-)
 

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Very early on I set the tappets on my 76 T140v at 2 and 4 per Plewsy's videos (bless his 'art) and with the little rattle, the bike ran splendid.
I got into the habit of 2 & 4 thou. and after the rebuild torque, occasional timing, rocker box spindle change, etc. It's been running fine under all conditions.
I think I will set it proper one spring day :) just to "see"
Have you run with both settings Sam?
 

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Discussion Starter · #7 ·
Hi DaveDone,

No, I have only run it with 6 and 8 thou.

However, I've just recently had the cylinder head refurbished and the guy who did it said that it was in a dreadful state, with very uneven rocker box mating surfaces, which would explain why the PO had them sitting on a "bed" of gasket cement.

All back together again and only started and run briefly to make sure everything worked, before sending the petrol tank and side covers off to be painted.

:)
 

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There is a common mis-conception,that the valve clearances will tighten up from expansion when the engine is hot.On a pushrod engine,they normally loosen and the intake clearance increases most (about 0.002" more on a Triumph).

Using a tighter clearance than the cam spec calls for is not usually a good idea.If a cam has 0.006" or 0.008" of quietening ramp,using 0.002" clearance probably won't even reduce valve-clatter.
A tight intake valve will lose you horsepower,and especially low-speed torque.It's not likely to cause mechanical damage if there is still some clearance.
A tight exhaust valve will lose a little power at first,until the valve burns.After that,you lose a lot of power.
 
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