busted choke relief spring

Now that my engine is good again, yay, I get to find out about all the other things that are still wrong. I had to take the carbs out to diagnose another leak and found the relief valve non-functional.
manual says "replace carburetor body" when this happens, and I'm sure not going to replace my body for a .002 gram spring.

I saw on a Honda forum that someone has drilled out the pin and replaced a spring that way, which would be a less desirable option if I can't find a used choke plate with good relief valve.

Has anyone been able to cobble something together something that works without drilling the pin out?

I'd remove the pin and get a new spring.  How hard could it be?  

I rebuilt some TK22's from a 550 and those have a similar sort of flapper valve in the choke plates.  On those carbs, the plates can come loose, which then gets ingested by the engine.  I removed the pivot pins, fixed the broken flapper, then restaked the pin in place, after slathering it with high strength epoxy.  

I guess my previous post didn't post. Yup, I took the pin out last night. I didn't think I had a bit small enough or steady enough hand to get it out without ruining those soft posts but I did.

Now I just need to find an appropriate  spring.

Nessism wrote:

I'd remove the pin and get a new spring.  How hard could it be?  

I rebuilt some TK22's from a 550 and those have a similar sort of flapper valve in the choke plates.  On those carbs, the plates can come loose, which then gets ingested by the engine.  I removed the pivot pins, fixed the broken flapper, then restaked the pin in place, after slathering it with high strength epoxy.  

That won't be coming out again then 

I had a problem with weak flapper springs causing hard cold starting on my 305 and couldn't find new springs.
I ended up drilling a small hole through each flapper and choke plate. Than tapped the hole in the plate. A small screw now holds the flappers tightly shut. Much easyer cold starts now at 7/8th choke. Of course, full choke will now stall out the engine. This modification has caused no ill effect.

ckahleer wrote:

I had a problem with weak flapper springs causing hard cold starting on my 305 and couldn't find new springs.
I ended up drilling a small hole through each flapper and choke plate. Than tapped the hole in the plate. A small screw now holds the flappers tightly shut. Much easyer cold starts now at 7/8th choke. Of course, full choke will now stall out the engine. This modification has caused no ill effect.
 

That's an Interesting last ditch option.

I have the opposite problem with my 305. It will never start with the choke closed, but I have to close the choke once it fires and keep it closed for 30-60 seconds in order to keep it running, then I can back it off. Maybe because one cylinder was rich and one lean at startup because of the flapper?  I dunno. I never really bothered to make sure my carbs were fully tuned the way they should be, but after rebuilding the engine twice I am not messing around anymore. I am taking the time now to try and do everything right with the fuel system. I am going through the full procedure in the manual checking the function of every last thing.

I figured I'd never find another spring with the same tension as the original unless I bought an entire carb. Since only one of the straight ends broke off, I straightened out a coil on that tiny and surprisingly strong spring (fun! not) and made a new end out of it. I finally discovered its a lot easier to work on it while it's on the pin. Seems like it may work although the resistance is slightly less. Maybe a tiny dab of jb weld to stake the pin in again

Well there had to be a catch. When I went to reattach the choke plate I find that the tiny machine screws self-destructed when I took them out. They seem to be a special screw with a spreader or something inside the hollow tips, designed to stay in the choke plate and out of engines.  If you zoom in you should see what I mean





Any ideas from the experts, other than finding new screws with lock washers??  These won't even thread in anymore and I'm not much of a machinist. Its possible I could deburr them but new ones sounds like a better idea.
 

I was able to get the screws back in, but it took some effort as the ends were buggered up like yours. If they woun't go in, new screws with red Loc-Tite should work.

ckahleer wrote:

I was able to get the screws back in, but it took some effort as the ends were buggered up like yours. If they woun't go in, new screws with red Loc-Tite should work.
 

Thanks for the inspiration to give it another go. I had to file off a couple threads on one but got em both back in.. I think its still plenty long. Now where's my Loctite...