TK carb adjustment question

[Ax-man]

WOW, Thank-you, this is very helpful . Part No. 1 was not in the carb or at least that I can tell anyway. That brass main jet had two little o rings on the main body when I took it out but nothing that looks like a seat that would go under that jet nor was there anything in the carb itself. Parts 13-16 are sealing good the carb finally passed the air test with the Mighty /Vac after I got that inlet needle to seat after correcting that metering lever. I got the fuel pump gaskets in right according to this diagram. I thought I might have had them in wrong .

I got an impulse signal from both the engine and the passage way in the carb is clear and the manifold gasket is in the correct place . So I know that is good.

I am going to take that carb back apart and see if that left over piece goes in under that main jet. The leftover part doesn't look quite right according to the pic but it is worth a shot. That part has to go some where in that carb and so far I haven't seen where it goes.

Again thank-you for taking the time to post this info and helping me out.

 

[DND 9000]

No problem, please let us know if it works when you`re done.

 

[backhoelover]

Might want to check crankseals if there leaking bad enough carb will not pull full from tank from loosing impulse

 

[backhoelover]

Pretty sure I have a bunch of them diaphragm in a draw from a ebay nos carb kit lot

 

[Ax-man]

I have gotten this 80 to run sorta. The engine is good mechanically compression excellent and no crank seal leaks . I checked all that stuff before ordering that carb kit.

After taking this carb apart again I found my problem on the metering side. That darn metering lever can't lift the needle off it's seat the way it is set now. I bought a cheapie generic primer blub at the hardware store and rigged it up . It works ok got fuel into the carb and was able to prime the metering side by using the plunger in the metering diaphragm cover to lift the needle off it' seat which it turn moves that plunger under the metering lever to allow fuel to flow out of that over flow tube . No return line to the tank . Clear as mud right.

Ok, after all this the darn thing still wouldn't start till I pressed that plunger in the metering cover holding the needle off it's seat . The darn thing started and ran under it's own power ,not correctly of course because it was basically a super rich flooding type running condition with that needle off it's seat. The darn thing quit after I took my finger off that plunger and the needle reseated but couldn't move and shut off the fuel supply.

Now somehow I have to figure out a way to raise the metering lever slightly and still have the metering diaphragm be able to do it's job to be able to lift the needle off it's seat to do it's job correctly . I am going to have to alter something because maybe that kit doesn't have quite the right parts like the original stuff. I suspected this problem from the start. That plunger rod right under the metering lever is part of priming system and doesn't have nothing to do with how the carb actually runs. I don't think it does anyway . We will see.

I am waking this trimmer up slow but sure but taking that carb on and off and taking it apart is getting old . It has become a battle of wills between me and this FS 80.

 

[DND 9000]

Have a look at the pdf file attached. This is from Zama but should also help you or give you the right idea how to adjust the metering lever on your TK (Teikei) carburetor.

 

[Ax-man]

I won ,Finally got it running. The problem was in that metering lever setting and the metering diaphragm metal part that moves the needle off it's seat was a different measurement from the old one. The old one was 3mm thick . The new one was 4mm thick. I don't think the old one was that worn down. Didn't look like it anyway.

How to solve this problem. I moved the metering lever up from 2mm to 1mm. I then used my old sealing gasket that goes under the metering diaphragm as a spacer then put the new stuff on top of that . It worked. The time I was doing this I had my bulb tester out checking the carb to make sure the needle stayed seated and unseated when it was suppose to. Anyway I purged the carb and fiddled with the settings and had a runner on the second pull. After a brief warm-up and carb tweaking this little 20 cc trimmer sounded strong . I'll see what tomorrow brings . Now all I have to do is retro fit my aftermarket kill switch and get a better purge bulb set-up and we should be good to go.

Again , I would like to say thank-you for the help and I hope anyone who digs this thread up in the future will find it helpful from my experience and others with these TK carbs. Even though they are dated it really isn't that bad of a carb just different and very touchy to adjust.

 

[DND 9000]

Good. Thank you for the response.

 

[scherbd]

I won ,Finally got it running. The problem was in that metering lever setting and the metering diaphragm metal part that moves the needle off it's seat was a different measurement from the old one. The old one was 3mm thick . The new one was 4mm thick. I don't think the old one was that worn down. Didn't look like it anyway.

How to solve this problem. I moved the metering lever up from 2mm to 1mm. I then used my old sealing gasket that goes under the metering diaphragm as a spacer then put the new stuff on top of that . It worked. The time I was doing this I had my bulb tester out checking the carb to make sure the needle stayed seated and unseated when it was suppose to. Anyway I purged the carb and fiddled with the settings and had a runner on the second pull. After a brief warm-up and carb tweaking this little 20 cc trimmer sounded strong . I'll see what tomorrow brings . Now all I have to do is retro fit my aftermarket kill switch and get a better purge bulb set-up and we should be good to go.

Again , I would like to say thank-you for the help and I hope anyone who digs this thread up in the future will find it helpful from my experience and others with these TK carbs. Even though they are dated it really isn't that bad of a carb just different and very touchy to adjust.

Ax-man, I have the old FS80 Still brush cutter with the same carb. Mine runs strong, but pushes gas out the over flow tube when running. I think the meter diaphragm is keeping the needle open all the time. As you did, I am going to compare old parts to new and maybe add another gasket to get it off the needle so it will seat. Thanks, Dan

 

[mudrat2]

Old thread but this info may help someone. The old TK carbs with the tickler button on the bottom have an o-ring under the purge valve that is destroyed by ethanol.

This causes fuel to leak out of the overflow tube while running.

The o-ring was not in any kit I could find and you need to pull the brass valve out of the carb body to get to it. I used a small collet chuck to grip the valve shaft. I also routed the overflow tube back into the tank and added a priming button pump to the overflow tube to pull fuel into the carb.