A few guys have emailed us asking about Stromberg 97 hand throttle parts and how to install them. We don’t supply the hand throttle parts on new Genuine Stromberg 97 carburetors simply because most of the carbs we supply go onto hot rods and the hand throttle is not required. Some guys use the parts off their own 97 when they update to a new model, of course, but if you don’t have the parts try Max Musgrove at 97 Express, who recons a lot of 97s and often has spare hand throttle kits. Email him at firstname.lastname@example.org . If you have parts, here’s how to fit them.
Align the holes and…
The Stromberg hand throttle parts came on the 97, 48, 40, 81 and LZ models. There’s the main lever with the ball on the end, a small collar, a spring and a cotter pin. Note that at the bottom end of the main lever, on the outside edge, half of the circle is missing (you can just see it in the pic). This mates with the tab on the inside edge of the small collar piece. The tab is smaller than the ‘half of the circle’ that is missing on the lever for a reason.
To install it, you push the lever onto the throttle shaft (obviously the other end to the foot pedal throttle bracket). Make sure that the ball is pointing outwards. It should slide right over the throttle shaft bush. If you have a brand new 97, we paint that bush. So you may need to scratch the paint off first. Make sure the lever spins freely on the bush. Then push the spring over the end of the throttle shaft. It goes inside the lever a little at the bottom.
…insert the pin
Now push the small round collar onto the end of the throttle shaft (compressing the spring) so that the tab on that collar fits into the gap (the ‘half a circle’) in the bottom end of the lever. Align the holes in the end of the throttle shaft and the collar and insert the pin. Make sure you get the holes in the correct alignment. You want the lever pointing to about 10pm when you put the pin in vertically. If you do this you will notice that when you pull on the pedal lever, the hand lever does not move because the collar tab rotates in the ‘half a circle’ gap in the lever (mentioned above). Without this, the hand throttle knob would move in and out of the dashboard as you drive. It may need a little adjustment to ensure that the hand throttle knob does not move in normal driving. One more thing. It’s a good idea to support the end of the throttle shaft with a block of wood when driving the new pin, to prevent tweaking it. And if you do use the hand throttle, push it back in to dashboard (the off position) before using the pedal. It’s not like a modern cruise control where the pedals (throttle or brake) automatically overide the hand throttle! Any questions? Email us at email@example.com
Update – 16 Sept 2015.
Max Musgrove sent us some pics of the clever jig they built to support the 97 throttle shaft to fit the hand throttle parts. Thought we’d share them with you.
Hand throttle fixture
Where the pin goes