1966 Sportster and Late 1966 FLH

These Tillotson carburetors were standard equipment on Harley motors in the years between the Linkert(M and DC) and the Bendix.  They had a unique feature, never before seen on a Harley carb:
The accelerator pump !
They "lacked" another feature the other carbs had . . . now it was gone.
The float bowl.
Gravity feed fuel flow from the tank.  Starting meant a few squirts, a choke, a couple kicks and it was running.  A simple design, with a hell-of-a-lot-of-parts !  There's more parts to these things (just look at a parts book).  I restored this one and still need the throttle cable holder metal strap deal and bolt that goes off the wood spacer block.  The bolt's hex head is displaced in the drilled recess in the spacer block.

You can buy these carbs at a swap meets sometimes for about $5.00 . . . But the carb kit is about $40.
The diaphragm is the weak link.  Big Noot said these things actually work pretty good, are tunable and have decent throttle response, and make power (at least on ironhead Sportsters).  The carb body came standard with a "racing bombsite fuel atomizer" that you pay big bucks for if you want one now.
You ever see those "vent tubes" sticking out the bottom, right side of Sportster tanks?  That tube fits a hose that vents to the top of the Tillotson fitting.  You don't need to run it.  I believe it was more of a gas vapor emission tube to keep it from venting to our squeaky clean atmosphere.

1 comment:

david ervin said...

Okay, so no one will read this but, whatever. My first Sporty was a 71 and it had a Tillotson. The bike ran pretty well but... I was between Omaha and Lincoln and she started sputtering. I tried to save the go but there was an off ramp & gas station; and it died. There was enough coast in her to get to the pump so I topped it off. Didn't need much...what the crap?! I kicked and I kicked and I kicked and I kicked some more. And then the crank locked up. At least no more kicking. When I pulled the plugs the first kick drenched my leg in gas. Now THAT'S flooded.

It took me a bit to figure the diaphragm stuck. From then on I carried a bicycle spoke wrapped around the right handlebar and when it got spitty I prodded the diaphragm and be back in business. What's that you ask? How do I take my hand off the throttle and still go? BWAHAHA. Throttle return?! You would need a leaf spring from a 56 Chevy to get that wire pulled back. Maybe two.

Now I see you can buy Tillotson "ticklers" (if you're rich). Where were they when I was 19? I wasn't rich then either but stupid can be the same thing.