High needle all the way in still rich

[backhoelover]

pg 15 on the walbro manual show you how to do the test with pictures

 

[big t double]

ok on the brass peice bypass . Take a small piece of 3/16 fuel line about 1 in long. make sure it is cut straight. put it over the bypass valve should be the same as the main valve. should let you blow. shouldnt let you suck back

If you use this method the high side needle must be fully closed. The way backhoe lover described how to check the main nozzle is exactly how I check them too. Poor mans vac/pressure gauge.

 

[CoreyB]

I took it apart and didn't see anything jump out as bad. However this is the first carb I have ever looked at. Soaked it in gas and tried to clean it up.
It did not improve it by much of any.
I will take it apart again get the numbers and take some photos.
Does anybody have a link to a rebuild kit?
I am trying to read up on the metering to see if I can rule that out for sure our hopefully fix it. The diaphragm almost felt cloth like so I am guessing that a new one would not hurt a thing. It did have some debris on it.
Thank you all for your patience and help.

 

[backhoelover]

here you go

 

[backhoelover]

rk 20hs that is the carb kit numbers

 

[backhoelover]

if it is a hs 118

 

[backhoelover]

I have the master carb check sheets from stihl. so far i have sent them out and no one has seen them but me. They are in word so i will have to send them email so send your email address if yo u want a copy it covers walbro, zama, tillotson

 

[backhoelover]

this will help too

 

[CoreyB]

Wow guys that is some great info. It will be a late night but feeling influenced.

 

[redtractor]

If yours has the notched metering lever, the diaphragm should have a nipple that needs to slide into it. Simply laying the diaphragm on top with that setup will hold the needle valve open all the time.

 

[CoreyB]

I thought I would share some photos I took. I tried to get as much detail as I could.
If you notice anything out of place please let me know.
I will try the other suggestions tomorrow and try and track down a rebuild kit as well. Our would it just be best to find a whole new carb?

 

[scallywag]

Could you post a pic of the tips of your mixture screws?

 

[CoreyB]

 

[hotshot]

Great pics right there.

That's also a high speed bypassed carb, a Tillotson HS221A. They probably changed to that in the later years to build a parallel design like the Walbro WJ type. That change was to help prevent idiots from roasting their top ends due to screwing the high speed adjuster screw in too far & thus too lean.

Attached is a pic of my older HS 118A that is not compensated. See how that brass slug is solid w/o a hole?

Now do the backhoe lover "suck-a-test" on your jet, as he spelled out in a previous post.

If the check valve fails, get a used carb off FleaBay or a sponsor here, and put a rebuild kit in it.

That high jet is replaceable from V.E. Petersen's up in Ohio, but it's easy to screw it up if you've never done one.

If the test passes, get a carb kit, check the welch plug for leaks or replace it, set the metering lever height flush to the floor edges, and it will tune fine.

There are full rebuild RK-23HS carb kits on FleaBay for $5.37 each delivered to your door. You want the metering diaphragm with the slotted nipple on the end to engage your metering lever fork, not a flat nub. There are two different types there

 

[CoreyB]

Ok so the best of my understanding and attempt, it seems that the it passes the suck blow test. So I am ordering this .
http://m.ebay.com/itm/TOLL-RK-23HS-...arburetor-Repair-Kit-/400700921075?nav=SEARCH
Hour it gets here fast so I can see if I actually fixed my first carb. Lol

 

[CoreyB]

Ok guys I got my carb kit today and think I have found the possible problem or at least a difference. I will post pics later.
I do have a question the kit I got has more than just gaskets. Should I try and replace all the pieces. I few I have no clue where they go like little screens and a needle or jet of some sort. Anyways all help is appreciated

 

[hotshot]

Should have a needle, fulcrum lever, 2 each screens & welch plugs. That's in addition to the 2 diaphragms and their gaskets. Throw out the two oblong flange gaskets (fiber/paper ones), as they are not for that Stihl saw.

Like I already told you, if the big welch is loose in your carb, replace it!

Metering side: replace the inlet needle, spring & lever, then set your lever height flush with floor of the metering chamber.

Pump side: install the big screen, fuel pump diaphragm, gasket, and cover with screws.

Pressure test it at 6 to 8# max with light oil or fuel mix to get it wet. If it holds with no bubbles passing the needle, then put the new metering gasket & diaphragm in.

If it leaks, buy a used HS-118 carb and re-use the new rebuild kit in it, as the needle seat is not replaceable, and leaks will cause the saw to flood itself out when just setting there.

 

[CoreyB]

Should the metering lever have any play on the plunger side?

 

[CoreyB]

Ok I think I got it. The metering lever had to be touch below the dish floor. Will test it in wood this afternoon and see.

 

[Chainsaw Jim]

Ok I think I got it. The metering lever had to be touch below the dish floor. Will test it in wood this afternoon and see.

Post a pic and I'll let you know if the lever is at the correct level. You don't want it set too low.