new to site! picked up a craftsman 5.2 30" bar!

[chainmailer]

I see is it acceptable to block it off safely? I was tuning on it this morning and turned in the low speed a 1/8 at a time and after about a half turn total she started responding and revs started coming down almost to wear I thought that was it but then another 1/8 and It wouldn't run at all! So must be a combo of things happening!

 

[Kensie1988]

I see is it acceptable to block it off safely? I was tuning on it this morning and turned in the low speed a 1/8 at a time and after about a half turn total she started responding and revs started coming down almost to wear I thought that was it but then another 1/8 and It wouldn't run at all! So must be a combo of things happening!

Well these carbs have what I call "bridged circuits (high & low)" I don't know what the technical term is. So you will in fact have to tune both circuits at the same time to find the sweet spot because changing the low does affect the high.

Edit, turns out "bridged" isn't the word for it, there are two low speed jets that assist the high speed just behind the intake butterfly and one angled back to the high speed.



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[Kensie1988]

High speed check/main nozzle check

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[Kensie1988]

And since I'm on one, your high speed governor works off the outlet under your metering lever

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[chainmailer]

Thx kenzie so much! Awesome pics, good job! Very helpful! Didnt have the kit rk-23 hs locally so had to order it online! Came today and I thought it (check valve) was supposed to be in kit! But I'm told no so will have to order it! Hope you dont mind another question? What is procedure for removing it? Thx again for all your help! I'm sure this thread will be helping other people for years to come! Craig

 

[Kensie1988]

Thx kenzie so much! Awesome pics, good job! Very helpful! Didnt have the kit rk-23 hs locally so had to order it online! Came today and I thought it (check valve) was supposed to be in kit! But I'm told no so will have to order it! Hope you dont mind another question? What is procedure for removing it? Thx again for all your help! I'm sure this thread will be helping other people for years to come! Craig

I'm actually working on finding a replacement for that check valve myself, I've seen some part numbers floating around but haven't had any luck being able to order any.

To remove the check valve you must remove the high speed needle and take a flat punch and drive it through from the basin into the venturi of the carb an let it fall out through the choke side. I've got a very long list of those check valve part numbers that I'm going to start going through until I find one that fits.

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[Marshy]

I didn't know Poulan made em that big. Awsome!

I didn't know Poulan made em that big. Awsome!

I'd give one a try.



Skip to 8:00 to see the 5200 cut.

 

[TRTermite]

There is some around here that may know the tillotson part number for that high speed check valve. I cant remember off the top of my head but it's a little round wafer check that inserts into the carb through the high speed circuit on the metering basin of the carburetor. They were kind of notorious for sticking over time causing funky run conditions. One of which being a lean run, im not 100% sure but this carburetors high speed is affected by the low speed setting some, I'm still troubleshooting the one I have and I think I have it narrowed down to the low speed circuit is not 100%.

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Getting into it deep you may scare some one away

 

[Marshy]

I wonder if you guys could replace that carb with one from a Husqvarna 285CD. They used a Tillotson HS-136B, C, D series. Same displacement saw.

 

[chainmailer]

Thx marshy awesome video love it! That's the saw I remember running it's an awesome saw! I would love to find a different carb that would work as you can hear they have a problem with the rpms not dropping instantly there is definitely a lag there which I think is inherent to this carb! There are a couple of stihl carbs that are close to working but not quite ( choke on wrong side ect.) But it wont scare me off I love a challenge! Thx again for the video it tells me that there is a design problem that you might not be able to totally get rid of! Thx again!

 

[chainmailer]

Thinking about it some more, I bet that if you were to find a different carb that would bolt up I have a feeling that this engine when transitioning from WOT to idle suddenly the engine would probably keep dieing! Which would explain the extra low speed port! So most likely is this carb is probably the most sensitive and difficult to tune! I ran into this same thing in a Nitro RC race car I had! Was all in the low speed needle! Had to slow down and make micro adjustments then run it and adjust again and again and again till you finally hit the "Sweet spot" and after that it was "ON LIKE DONKEY KONG" ! LOL gonna find out! CRAIG

 

[Kensie1988]

I wonder if you guys could replace that carb with one from a Husqvarna 285CD. They used a Tillotson HS-136B, C, D series. Same displacement saw.

I believe I have one of these lying around, I might have to see if its possible.

 

[Kensie1988]

Thinking about it some more, I bet that if you were to find a different carb that would bolt up I have a feeling that this engine when transitioning from WOT to idle suddenly the engine would probably keep dieing! Which would explain the extra low speed port! So most likely is this carb is probably the most sensitive and difficult to tune! I ran into this same thing in a Nitro RC race car I had! Was all in the low speed needle! Had to slow down and make micro adjustments then run it and adjust again and again and again till you finally hit the "Sweet spot" and after that it was "ON LIKE DONKEY KONG" ! LOL gonna find out! CRAIG

I checked all of the circuits last night with high # test fishing line, they were all clear, so that tells me the issue is definitely in the main nozzle check valve, or there is an issue with another sensitive area I will have to track down. Keep at it and if you make any progress let me know!

 

[Marshy]

I believe I have one of these lying around, I might have to see if its possible.

I have one on a good running 285. If you need pics let me know.

Looks like you can still buy a new HS-173A.

https://sleequipment.com/tillotson-genuine-part-hs-176a-carburetor.html

 

[chainmailer]

found nozzil check valve part #530034105 at jacks small engine parts online for $15 i think it was!

 

[Kensie1988]

That's it, kinda high if that's not what the issue is though.

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[chainmailer]

yes, i agree im pretty sure thats my problem or that govenor valve! ive ruled out crank seals and intake air leaks! im trying to decide weather to just buy the new carb and just be done with it! id have $150 in it after new chain! someone said i stole it for $10 ha -ha! Does anyone know what a saw like this in good condition would sell for? thx everyone for all your help! craig

 

[Kensie1988]

More than $150 lol so your still in good shape

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[Marshy]

I would try the $15 check valve. If that doesnt work then why not just plug the govenor? There are threads on how that is done. It's still a HS series carb so should be in the same location as the ones used on the 285/2100 Husky.

Also, this manual might help you some.

 

[chainmailer]

Thx marshy your probably right! We got some big wood down from all the storms this winter so I cant wait to buck em up and make big piles of sawdust fast! Lol and thx for the service manual very nice! Big help there! Craig