TWE143 Posted July 28, 2011 Share Posted July 28, 2011 I have a Sisson choke on a WW2 Civilian Defense trailer pump, Chrysler flathead engine. Should the bottom flange around it be flat? I suspect the bottom should be flat, but it is deformed so symmetrically that I need to ask anyone who knows. The attaching bolts were both broken, possibly by rust "pack out." The deformation might have been caused by the large bolt tension. But perhaps there should be a small space between the exhaust manifold and the choke. Does anyone have an early 1940s Chrysler engine with a Sisson choke that could check its appearance and let me know? Link to comment Share on other sites More sharing options...
ply33 Posted July 28, 2011 Share Posted July 28, 2011 I believe that a number of people over on the P15-D24 discussion forum can help you with the Sisson choke. I am not that familiar, but I believe there is a gasket that goes between the manifold and the choke housing. If it has disintegrated and fallen out then there might be a gap showing there.www.P15-D24.com - Powered by vBulletin Link to comment Share on other sites More sharing options...
auburnseeker Posted July 29, 2011 Share Posted July 29, 2011 There is suppose to be a gasket between the choke and manifold. I made a new one for mine out of a sheet of dare ai say it old Hard thick asbestos matt. Link to comment Share on other sites More sharing options...
Rusty_OToole Posted July 29, 2011 Share Posted July 29, 2011 The base should be flat, held down by 2 small bolts, and there should be an asbestos gasket between the choke and manifold. It is the same material used for exhaust manifold gaskets.Dont know if the gasket is still available, I cut my own from a Ford flathead intake manifold gaskets. Link to comment Share on other sites More sharing options...
Rusty_OToole Posted July 29, 2011 Share Posted July 29, 2011 There is a specific method for adjusting the choke. Not difficult if you know how. If you do not know or do not have a manual I can tell you how to do it. Link to comment Share on other sites More sharing options...
auburnseeker Posted July 29, 2011 Share Posted July 29, 2011 My heat riser is stuck open. I did everything to try to free it when it was off the car and couldn't. I put a new sisson choke on my car when I had the engine apart for a rebuild. My choke stays on too long or strong and I have to raise the hood and pop it manually off by puching the arm down. How do I set it weaker? It starts super quick with just about a turn of the motor. I would love to not have to get out everytime and open the hood. Link to comment Share on other sites More sharing options...
TWE143 Posted July 30, 2011 Author Share Posted July 30, 2011 (edited) Reply to #2. Yes, I discovered that a gasket was needed thru an article in Skinned Knuckles. However, the ears are deformed, or maybe made that way; that is one of the things I need to know. Edited July 30, 2011 by TWE143 (see edit history) Link to comment Share on other sites More sharing options...
TWE143 Posted July 30, 2011 Author Share Posted July 30, 2011 (edited) Reply to #3. I discovered the need for an insulating gasket in an article in Skinned Knuckles. But I don't know what shape it should be. Oval outside is obvious, but what did you do for the inside--did you have the old one for a pattern? I have some high temperature gasket paper--gray heavy stuff. Edited July 30, 2011 by TWE143 (see edit history) Link to comment Share on other sites More sharing options...
TWE143 Posted July 30, 2011 Author Share Posted July 30, 2011 (edited) Reply to #5. I do not have a manual, but the Skinned Knuckles article gave the method in a sentence of so. A pin thru the hole in the shaft should engage the notch in the base. Edited July 30, 2011 by TWE143 (see edit history) Link to comment Share on other sites More sharing options...
Rusty_OToole Posted July 30, 2011 Share Posted July 30, 2011 (edited) I just cut the gasket a little bigger than the base of the choke and drilled 2 holes. The hole drilling goes better if you sandwich the gasket between 2 pieces of scrap wood. The inside is solid. I believe it is there to insulate the choke so it does not release too soon.procedure for adjusting choke.Start by removing the air cleaner.There is a tiny hole in the brass shaft of the choke and a matching hole in the base, or else there is a slot in the bearing. Open the throttle and line up the holes. Stick a piece of wire through the holes to lock the choke in place. You need a perfectly straight wire that fits as accurately as possible. I prefer to use a small drill bit.You will need to hold the throttle open about one third to free the choke.With the choke locked in place, loosen the clamp screw on the choke lever. push the lever upward until the choke blade is closed tight. Holding the lever in position, tighten the clamp screw. Check the setting by feeling the choke blade to make sure the slack in the linkage is taken up. Remove the adjusting tool.Check carefully to be sure the choke works smoothly without binding or sticking in the closed position.Replace the air cleaner. Be careful the tightening clamp does not bind the choke mechanism and that the fast idle and choke mechanism are not gummed up with oil or grease.NOTE #1 Hold the throttle partly open when making adjustments so the fast idle cam is released.NOTE #2 Do not put oil, grease or other substance on the choke mechanism or you will gum it up. The choke should be clean and move freely.Incidentally the choke spring does wear out and lose its tension over time. New ones turn up on Ebay or the old parts specialists might have one. Edited July 30, 2011 by Rusty_OToole (see edit history) Link to comment Share on other sites More sharing options...
TWE143 Posted July 30, 2011 Author Share Posted July 30, 2011 Reply to #10. Thanks Rusty.The most important to me is that the gasket is solid inside. I have several arch punches; one should be correct for the holes. Adjustment sequence is appreciated. Link to comment Share on other sites More sharing options...
Rusty_OToole Posted July 30, 2011 Share Posted July 30, 2011 (edited) My heat riser is stuck open. I did everything to try to free it when it was off the car and couldn't. I put a new sisson choke on my car when I had the engine apart for a rebuild. My choke stays on too long or strong and I have to raise the hood and pop it manually off by puching the arm down. How do I set it weaker? It starts super quick with just about a turn of the motor. I would love to not have to get out everytime and open the hood.You can get a spray can of heat riser lube at auto stores. Spray some on and gently tap the manifold and the heat riser with a small hammer. Do not hit hard. You are trying to set up a vibration to vibrate the riser loose. If you can get it to move the slightest bit move it back and forth, back and forth and it will come free eventually.It is common for them to freeze up but they usually come free with a little work.Once you get it free lube with graphite when you lube the car. Do not use oil, grease, penetrating oil or anything else. They will only gum it up.Adjust the choke according to the method in the post above. If it still sticks examine the choke carefully and see why. Be careful the air cleaner clamp is out of the way and do not tighten it too tight.If the air cleaner clamp is worn to the point it will not hold the air cleaner you may have to take it off and adjust it. The > shape gets spread open. To close it up lay the clamp on a hard surface like an anvil and tap all around with a hammer. Do not hit too hard, the trick is to close it up evenly but not too much. Once you get it adjusted to the same angle as the carb and air cleaner it will hold tight. You only have to tighten the screw snug. Do not overtighten, that is how they get bent and how the choke gets jammed. Edited July 30, 2011 by Rusty_OToole (see edit history) Link to comment Share on other sites More sharing options...
hwellens Posted July 30, 2011 Share Posted July 30, 2011 See if this helps: Link to comment Share on other sites More sharing options...
TWE143 Posted August 12, 2011 Author Share Posted August 12, 2011 Reply to #13. I was away for a while. Yes it does help, especially the sketch. Thanks. I need to find the choke rod--where did I hide it from myself! Link to comment Share on other sites More sharing options...
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