[Gary Maker]

I spent some time trying to figure out how to make a good manual choke activation setup that was simple and straight forward.

I have seen some setups that, well, almost made me cringe. A beautiful 35% Yak 54 with a DA twin cylender gas engine. It was quite an elaborate linkage setup where the activation linkage came out the front of the cowel, just behind the prop. He would reach in and pull the linkage to close the choke, flip the prop until it burbled. THEN reach in behind the prop to push it to open the choke. Hmm. Personally I guess I just don't like the idea of putting my hands in behind the prop when everything is turned on. Just a personal preference.

I finally figured out a simple way that is easily accessable and works flawlessly.

I made a standoff out of 1/8 aircraft ply that had a base about 1" wide and 1 1/4" long. Glued it to the side of the fuse inside about 6" behind the firewall on the choke side of the engine. Used a couple of Triangle pieces of ply to brace it for a good firm mount.

I then used an aileron bellcrank and bolted it to the standoff platform. One linkage rod with clevis goes from the bell crank to the outside of the fuse side. The other linkage rod uses a clevis at the choke lever on the carb and a Z bend in the other arm of the bell crank. DONE!

When you pull the rod on the fuse side, it in turn actuates the bell crank shaft to the choke to pull the choke lever to the "ON" position. Ignition on, flip the prop till it barks, push the leaver in, choke opens or to the "OFF" position, flip the prop till the engine starts...Perfect, simple working choke lever actuation setup.

NOTE: You will see in the pics that there is NO metal to metal contact using this setup. Nylon clevis to the metal throttle arm, Metal clevises to the nylon bellcrank. LHS has bellcranks for a couple of dollars each. Cheep eh?

Here are a couple of pictures to show the setup Hope others find it useful.

[scott H]

ive got to see these pics gary ive been deciding on what way to go manual choke or servo choke. ive been afaid to go servo choke because my clumbsie fingers might shut the engine down in flight. scott

[Gary Maker]

OK Scott, I hustled just for you and got the pics online... Hope it works as well for you as it does for me. Cost is next to nothing and it works perfectly!

[JeffElecRC]

Great Tip Gary! I like it and will probably try that on my next 50cc build. It's definately lighter than a choke servo, and it happily makes use of a couple widgets and thingies we've all got lying around.

[scott H]

thanks alot gary much aprecciated. excellent idea. scott.

[GMACKAY]

HY Garry i did the same thing on my yak it is nice and clean looking i put the choke
and the fuel dot and pin switch all on the same side nice and clean . i all so put a nice dash panel in and new pilot.thanks to Lee p.

[Vulcan1]

Gary,
Good ideas and thanks.
John

[bobbremner]

Looks like a great idea. I was lead to believe that a DA will not "kick" unless the eng is flipped fast enough to start. The ignition will not turn on until it it sees enough RPM. I have two DA 50s with the choke behind the prop and they work great. I have never had the engine kick unless it was flipped hard enough to start.

[Gary Maker]

Originally Posted by bobbremner

Looks like a great idea. I was lead to believe that a DA will not "kick" unless the eng is flipped fast enough to start. The ignition will not turn on until it it sees enough RPM. I have two DA 50s with the choke behind the prop and they work great. I have never had the engine kick unless it was flipped hard enough to start.

Well, your probably right my friend. I guess its just me, as I don't feel comfortable with my hands reaching in behind the prop when everything is turned on. To me, it seems a lot easier to pull a choke leaver from the side of the fuse rather than reaching in the front of the cowl around the prop for the leaver. I don't see it taking any less time and/or cost and materials doing this way either. I just thought it was a neat, easily accessable manual choke setup that perhaps others would be interested in seeing.

[scott H]

on electronic ignition once the switch is shut off there is still enough charge in the unit to give one more spark at the plug . dont chance it if you move the prop were as the magnet passes the hall switchgiven the right conditions (COMPRESSION GAS AIR ECT.)IT COULD POTENTIALY FIRE . ive seen the front choke idea not my cup off tea. on a engine with electronic ign.