Stihl 361 Leaky Carb

[16TAF]

I’ve been working on a Stihl 361 and the only issue I’m having is the carburetor pushing fuel out when the saw sits. When I take the air filter housing off it’s wet with fuel where it meets the carburetor.

I’ve installed a new carburetor kit and the metering lever has been checked and is set properly. I’m thinking the carb has a bad seat?

Any help is appreciated, I’m fairly new to working on these and carburetor issues are a pain for me.

 

[FederalQ]

If you don‘t have the tools to pressure check things the cheapest option may be to buy an aftermarket carburetor and try it. I know mine has a weep hole drilled below the intake floor that drains through the cylinder wall into the crankcase. That may have been a running change to alleviate fuel pooling on the bottom of the intake boot. You could look through the carb to see if one is there.

 

[16TAF]

If you don‘t have the tools to pressure check things the cheapest option may be to buy an aftermarket carburetor and try it. I know mine has a weep hole drilled below the intake floor that drains through the cylinder wall into the crankcase. That may have been a running change to alleviate fuel pooling on the bottom of the intake boot. You could look through the carb to see if one is there.

I actually have an aftermarket carburetor coming tomorrow. I do need to order a pressure and vacuum tester.

 

[Stump Shot]

I actually have an aftermarket carburetor coming tomorrow. I do need to order a pressure and vacuum tester.

One for carburetors is fairly affordable. Here's a generic made one...
https://www.ebay.com/itm/1574148677...xI%2B%2BcuetcFeybK7I|ampid:PL_CLK|clp:2332490

 

[Stump Shot]

Tip- Soak gaskets in fuel mix prior just to installation so they will swell and seal as well as make sure they are on the proper side of the diaphragm.
Also, metering lever height needs to be adjusted to the exact proper height with the corresponding gauge for correct function.

 

[Junk Meister]

One for carburetors is fairly affordable. Here's a generic made one...
https://www.ebay.com/itm/157414867741?_trkparms=itmf=1&aid=1110006&rkt=4&asc=20231107084023&mech=1&algv=SimVIDwebV4WithCtxRankerV1UnifiedFeatures&pmt=1&amclksrc=ITM&sd=167977715065&sid=AQAKAAAAEDZ4oDux4lqMYwQZVXpuoaM=&itm=157414867741&noa=0&plcampt=0:152368487019&algo=HOMESPLICE.SIM&ao=1&rk=4&pid=101875&b=1&mehot=none&lsid=0&meid=332e721b90ca44aa96b3fbf6508444e0&pg=2332490&_trksid=p2332490.c101875.m1851&itmprp=cksum:157414867741332e721b90ca44aa96b3fbf6508444e0|enc:AQAKAAABELbQdNnV9E6H66rV4nIZYAZCOANuR76zl8wG%2FmKawEdd%2FZzO2T5yUdpwsFRr7Sz0JKF0FrRyP%2BU23IPpoQBmyWSlNzZWWsBunmKXW5ZVTR9HXN6wmLKvJGGEQDQIgknvzannydDdm4wvHfbV3zsf2NUz%2Bp015QGzIsdDzS5js%2BFWZZgNzGdJp2%2BBGvEhmDLtg%2FYaCxMMoPTdhZmMs%2BjpOfhMkSGwb8cr%2F9EB%2BZVcN1Ie2yfmDgoCX6eksE5vCGg9D4DLYr0jb%2BHFiquDno8ZrLlcJthF6VbjLCWVee87htYtUY3EjeUmZV0Byza9nbFl9UNVOodz1KBx8FGVCbw8Kn7lrBx8xI%2B%2BcuetcFeybK7I|ampidL_CLK|clp:2332490

I have a Silverline Mitey Vac setup, Will this carb tester work better or be more convenient? TIA

 

[Junk Meister]

One for carburetors is fairly affordable. Here's a generic made one...
https://www.ebay.com/itm/157414867741?_trkparms=itmf=1&aid=1110006&rkt=4&asc=20231107084023&mech=1&algv=SimVIDwebV4WithCtxRankerV1UnifiedFeatures&pmt=1&amclksrc=ITM&sd=167977715065&sid=AQAKAAAAEDZ4oDux4lqMYwQZVXpuoaM=&itm=157414867741&noa=0&plcampt=0:152368487019&algo=HOMESPLICE.SIM&ao=1&rk=4&pid=101875&b=1&mehot=none&lsid=0&meid=332e721b90ca44aa96b3fbf6508444e0&pg=2332490&_trksid=p2332490.c101875.m1851&itmprp=cksum:157414867741332e721b90ca44aa96b3fbf6508444e0|enc:AQAKAAABELbQdNnV9E6H66rV4nIZYAZCOANuR76zl8wG%2FmKawEdd%2FZzO2T5yUdpwsFRr7Sz0JKF0FrRyP%2BU23IPpoQBmyWSlNzZWWsBunmKXW5ZVTR9HXN6wmLKvJGGEQDQIgknvzannydDdm4wvHfbV3zsf2NUz%2Bp015QGzIsdDzS5js%2BFWZZgNzGdJp2%2BBGvEhmDLtg%2FYaCxMMoPTdhZmMs%2BjpOfhMkSGwb8cr%2F9EB%2BZVcN1Ie2yfmDgoCX6eksE5vCGg9D4DLYr0jb%2BHFiquDno8ZrLlcJthF6VbjLCWVee87htYtUY3EjeUmZV0Byza9nbFl9UNVOodz1KBx8FGVCbw8Kn7lrBx8xI%2B%2BcuetcFeybK7I|ampidL_CLK|clp:2332490

I checked a donyboy UT video He gave the parts $ for Walbro as 57-11-1 I looked on the bay and didn't see one googled it and $383 so I never looked any farther. I bought the STENS @Stump Shot suggested in post #4.. Theng U Verry MUCH.

 

[Sloughfoot]

One for carburetors is fairly affordable. Here's a generic made one...
https://www.ebay.com/itm/157414867741?_trkparms=itmf=1&aid=1110006&rkt=4&asc=20231107084023&mech=1&algv=SimVIDwebV4WithCtxRankerV1UnifiedFeatures&pmt=1&amclksrc=ITM&sd=167977715065&sid=AQAKAAAAEDZ4oDux4lqMYwQZVXpuoaM=&itm=157414867741&noa=0&plcampt=0:152368487019&algo=HOMESPLICE.SIM&ao=1&rk=4&pid=101875&b=1&mehot=none&lsid=0&meid=332e721b90ca44aa96b3fbf6508444e0&pg=2332490&_trksid=p2332490.c101875.m1851&itmprp=cksum:157414867741332e721b90ca44aa96b3fbf6508444e0|enc:AQAKAAABELbQdNnV9E6H66rV4nIZYAZCOANuR76zl8wG%2FmKawEdd%2FZzO2T5yUdpwsFRr7Sz0JKF0FrRyP%2BU23IPpoQBmyWSlNzZWWsBunmKXW5ZVTR9HXN6wmLKvJGGEQDQIgknvzannydDdm4wvHfbV3zsf2NUz%2Bp015QGzIsdDzS5js%2BFWZZgNzGdJp2%2BBGvEhmDLtg%2FYaCxMMoPTdhZmMs%2BjpOfhMkSGwb8cr%2F9EB%2BZVcN1Ie2yfmDgoCX6eksE5vCGg9D4DLYr0jb%2BHFiquDno8ZrLlcJthF6VbjLCWVee87htYtUY3EjeUmZV0Byza9nbFl9UNVOodz1KBx8FGVCbw8Kn7lrBx8xI%2B%2BcuetcFeybK7I|ampidL_CLK|clp:2332490

I've got that one. It works great for pressure testing these little carbs. Kinda slow airing up footballs and basketballs though.

 

[Coupe]

Find someone with a pressure tester and put 8 or 10 pds of pressure
and if will not hold it would point at the needle and seat. And if you put
a new needle in I would say your seat is faulty.

 

[16TAF]

Find someone with a pressure tester and put 8 or 10 pds of pressure
and if will not hold it would point at the needle and seat. And if you put
a new needle in I would say your seat is faulty.

I’ve got the tester Stump Shot posted coming tomorrow. Hopefully I can find the issue.

 

[cookies]

remove the needle and use a pencil tip to scrub the seat clean and it will highlight any wear ridges, scratches etc

 

[Stump Shot]

I’ve got the tester Stump Shot posted coming tomorrow. Hopefully I can find the issue.

Test to 7 PSI or .5 BAR for a minute and it should either hold or if it leaks down ever so slightly in two minutes is a pass. Otherwise look for leaks in a glass jar of water with the hooked-up and pressurized carb dunked in. Where the air bubbles come out is the clue to where it's leaking from and what needs attention.

 

[EFSM]

Walbro uses a chrome plated needle seat that is quite durable, but I have see them wear through to a yellow metal after a lot of hours. It is possible to replace the seat if you have a donor carburetor—I’ve done this quite a few times. Measure the distance from the seat to the pump face of the carb, use a small punch to drive the seat out the filter chamber, and install a new seat the same depth.

 

[16TAF]

I got the pressure tester today and tested the carburetor. After adjusting the metering lever down just a tad it’s holding pressure. It’s still seeping fuel. It’s coming out of the hole with the screwdriver pointing at it.

 

[FederalQ]

That‘s the impulse circuit. Did you change out the pump diaphragm?

 

[16TAF]

That‘s the impulse circuit. Did you change out the pump diaphragm?

Yes, it was changed

 

[EFSM]

Normally a leak there means a perforation in the pump diaphragm.

 

[16TAF]

Normally a leak there means a perforation in the pump diaphragm.

I just tried an aftermarket carburetor and it was leaking from the same spot.

 

[FederalQ]

You can test to make sure the tank vent is operating with the pressure tester. The vent is located under a small panel on the clutch side near where there would be an arctic switch by the handle mount. Fine debris can accumulate there.

 

[16TAF]

You can test to make sure the tank vent is operating with the pressure tester. The vent is located under a small panel on the clutch side near where there would be an arctic switch by the handle mount. Fine debris can accumulate there.

I hooked the pressure tester to the fuel line and it wouldn’t build any pressure. The fuel line is new OEM and the vent looks clean. The fuel cap is new OEM also.