The 35438 choke control knob, red plastic, three horizontal anti-slip slots that work even with winter gloves on. An inner shaft with a gourd hole pressing the choke push rod of the engine, one pinch closes or opens the choke plate, shaft and rod meeting hard, no cable, no spring, a solid feel under the hand. Two base versions, the flat one with a locating block for the flat seat, the tapered pointed one for the boss seat, look at the bottom of the old knob and take the same. The paired 35440 takes the throttle, the two shafts shaped differently, do not buy them crossed. Replace it when it will not pinch, the choke does not follow at full travel, the inner shaft is worn round and slips, the plastic cracks, or the base wears flat, a cracked shell can be replaced, a worn shaft means the whole knob goes. On install, the shaft mouth on the push rod, pinch twice and see if the choke follows, engines in the same series mostly fit, but fit is not guaranteed for every one, so comparing against the old knob is the safe way.

 FAQ 

Q1: What is this knob for?

A choke control knob, part 35438, red plastic with three anti-slip slots, its inner shaft pressing the choke push rod to close or open the choke plate at cold start, for H series horizontal engines on snowblowers, mowers and rototillers.

Q2: Is it the throttle knob, 35440?

No. The 35438 controls the choke and the 35440 controls the throttle. They look alike but the inner shafts are shaped differently and do not cross-fit. If your machine needs the throttle knob, take the 35440, or the set of both.

Q3: Which base should I take?

Look at the bottom of your old knob. A flat base with a locating block fits the flat seat, and a tapered pointed base fits the boss seat. Fit is not guaranteed for every engine, so checking against the old knob is the safe way.