Triumph Rat Motorcycle Forums banner

1 - 7 of 7 Posts

·
Registered
Joined
·
31 Posts
Discussion Starter #1
Hi,

I've just fitted a set of copper coated, allen key, mushroom head tappets to my 64 3TA.

How do I set the gap, there is no way I can see to do this visually. On the old ones you could just turn them one full flat & that would set the gap.

Any suggestions on how to set these type please?

TIA,

Andy.
 

·
Registered
Joined
·
1,293 Posts
You are unable to turn the adjusters back 90 degrees, because they are not square?

Anyway, a full flat on the original square topped adjuster is about 0.008”, just for interest.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #3
These new tappets are round, this is what makes it difficult to set them.

I can't be the only person to have these fitted?

Thanks,

Andy.
 

·
Registered
Joined
·
5,461 Posts
Unless I’m misunderstanding the issue, you put the hex key (Allen wrench) in the hex and make contact with the valve then move the wrench handle counter clockwise 90 degrees which would be the same as one flat on the old type square head.
 

·
Premium Member
Joined
·
9,796 Posts
I don't understand either.
I have allen headed tappets on my t140

Loosen the tappet, slip in the feeler gauge, tighten the tappet using the lawn key and nip up the nut. Remove feeler and re insert it to check
 

·
Banned
Joined
·
47 Posts
All adjuster tips are round, though their roundness may be of different radius.
The thread of the adjuster is still the same as it ever was (26 tpi BCY/CEI) in your case most likely. much later they changed to 24 tpi.
For either of these threads it is good enough to assume 40 thou for each full turn.
So you can use the "contact and back off" technique or feeler gauges, according to your preference. It doesn't make any difference, except if using feelers you may have to make a longer kink at the end of the blade.
 

·
Banned
Joined
·
976 Posts
They are a bit fiddly to set with feeler gauges, thats why the side plugs on the rocker boxes came on the late engines. I usually set my intakes to "barely perceptible movement" and exhaust to "faint click" instead
 
1 - 7 of 7 Posts
Top