John Deere STX38 , Leaking Needle and Seat

This carb was leaking gas into the intake manifold. It can fill the engine with fuel, very dangerous.

[@dargno]

No matter how many carb video's you do, I always learn a new way of going about things. Everyone does things different and, frankly, your way is easier than mine most of the time. Thanks for making my life easier lol

[@BrucesShop]

I just film what I do.

[@lukedvisscher4676]

That last comment. "She's probably running a little leaner than before!" Just cracked me up Bruce. Thanks!

[@BrucesShop]

I think it was.

[@not2fast4u2c]

I like watching all the different carbs you have done ..I learn something new each time

[@BrucesShop]

Thanks Jim

[@Mr_Tecumseh]

I'm glad you showed the carb kit number, it made my life easier. I have an STX38 in now. The gas leaked into the case and slowly made a big mess. I thought it was an engine seal or gasket leaking oil, nope it was gassed down oil coming thru the governor shaft. I had another kohler engine identical I was going to stick on in place and worry about the seal/gasket later. It was just the carb so now I dont have too. But I took mine apart cleaned it and now I don't hear any air leaks, but I'm changing that needle to be safe. Selling machine, don't need that happening again. I have the yellow deck STX38. Their will be a breif video.

[@BrucesShop]

Right on.

[@rickg4802]

It's me again Bruce. Finally got that 6.75 HP B&S to prime. I cleaned the filter housing again and used 2 gaskets, one I modified a bit, but it works. Thanks for all your help.

[@BrucesShop]

Good for you R Greene. Persistence is the key to fixing small engines.

[@Dastardly84]

This year was the first time I started replacing the brass seats in the Walbro carburetor on Briggs engines. I didn't even know you could do it before. The same can be done on Kohler carburetors. Wish I knew a few years ago as I tried replacing the needle and it never fixed the problem, even though if you blew into the carburetor inlet no air escaped. I ended up buying new carburetors for those engines. Keep em' coming Bruce.

[@BrucesShop]

Thanks for the great comment.

[@michaelfredrickson4325]

This was a great video. Thank you for taking the time to show us the process.

[@BrucesShop]

You are welcome.

[@MrGoosePit]

My Scott's branded John Deere has a Kohler Command engine. Noticed the gas tank near empty and thought it strange. Checked the oil and sure enough it was full of gas. Got the carb kit with the seat included. Used the self-tapping screw/bolt trick to get the old seat out. Pressed the new one in with a vise. So far, so good. I also added the gas-line cutoff for backup. If I'm not using the tractor for long periods I too shut the gas off and run the carb empty. Thanks to you, and some others on Y.t., I had confidence to try the fix myself. Thanks as always Bruce!

[@BrucesShop]

Yes these brass seats are tricky this one just took a new needle. You may have heard the disappointment when I said Brass seat ARGH!!!

[@larryjones6049]

Like I said I did work in shop for 20 years. I think you would be a huge asset in a professional shop your that good. You would be surprised at how most can’t do what you do. Great.

[@415orazio]

Thanks for all you videos. I have learned much from watching them. I also own a JD STX38 with a yellow deck and bought it used over 20 years ago. My home sits on just shy of 1/2 acre and I have had excellent luck with it and it is still going strong. I find it interesting though after watching this video, that the carb on my mower has a fuel shutoff solenoid on it that attaches to the bottom of the fuel bowl. I have a Kohler CV12.5S engine on it, and not sure if the one you worked on had the same. Keep the videos coming and thanks again.

[@BrucesShop]

I think the yellow deck STX38 are just a bit better machine.

[@Jake-lr8zy]

Good Job as Always Bruce. I Always Learn Something New Each Time I Watch Your Videos.

[@BrucesShop]

I learn something too. I really do

[@tonym6920]

HI, great job Bruce! I wish I had that much space in my garage, lol. Your videos are great, thanks!

[@BrucesShop]

It takes time every afternoon to clean it up.

[@watermanone7567]

Nice video. I have used a q tip cut one end off and put it in a low speed drill, use a little polishing compound and run it in the seat pocket for a few seconds to polish the seat. Flush it out really good with carb spray. Seems to get rid of any varnish, fine scratches etc. and works really good. Then when the needle is installed it has a nice surface to run on and it seats well. Thanks for the video's.

[@BrucesShop]

Great idea.

[@Budro4764]

I was going too comment about the same thing with the Q Tip and valve grinding FINE compound.... Ethanol gas eats up those Viton tips on those needles........ If that trick doesn't work with the Q Tip then you need to change the brass seat. Which is a different kit and more expensive. 40 bux U.S. I make my own jack out tools for those seats.......... Briggs carbs has those same brass seats on some of their carbs also.... A pain in the but if you don't have the tools to jack them out...........

[@watermanone7567]

Yes, If they are to gone, I use a 1/4-20 tap and 1/12 inch screw with a nut and washer on it and jack the old seat out. Install the new one with a Toro 815990 installer seat tool. Taps in pretty easy. Usually works great and fast to do with this homemade tool. Wish I could find a 1/4-20 self tapping bolt, it would make it even faster not to have to tap the old seat.

[@Budro4764]

Do you have a Fastenal store in your area ?? They have them ~!~!

[@watermanone7567]

I will check. I think one is about 15 miles from here.

[@KensSmallEngineRepair]

Do you have a Mityvac? I generally test for pop off pressure on needles and seats. 5-10 psi is normal, under 5 or not holding at all means leaks. I've seen many motors hydraulic due to gas in the oil, that's why I always say CHECK THE OIL EVERY TIME YOU USE A PIECE OF EQUIPMENT. Past the full mark on the dipstick smelling like gas is a dead giveaway to a bad needle and seat. Love the videos, need to get a recorder so I can upload some of my customer's work.

[@BrucesShop]

You should do a few videos.

[@SteveRobReviews]

Now that sounded just great to me. Nicely done Bruce

[@BrucesShop]

Thanks Steve

[@Turningwrenches85]

Excellent job, fixing another machine sir cant wait for another video.

[@BrucesShop]

Thanks John

[@Turningwrenches85]

Bruce Pender your welcome

[@alkuhn4883]

I noticed on this, "John Deere STX38 , Leaking Needle and Seat" video that the fuel filter "small engine" generic style was being used. This style of filter has a coarse wire filter (fly screen) that will only stop large rocks and small animals. The automotive style with a paper element will filter far smaller particles for about the same price. Having worked at FRAM Canada, I saw the results of inferior filtration on a variety of applications where fluids needed to be cleansed. "You can pay me now, or pay me later".

[@BrucesShop]

Thanks Al appreciated.

[@joeo1352]

Looks good Bruce

[@ZippoVarga]

Great video as always My Great Northern Friend! Cheers! Sean~

[@BrucesShop]

Thanks Sean. As always.

[@jean-luclevesque3070]

Hey Bruce, not sure this is related but my JDstx38 back deck starts fine, runs well for 10 minutes then stalls out. Like it is overheated and needs to cool down

[@BrucesShop]

I would check the engine coil if the entire machine shuts own. One thing about coils when they start failing the very small wires in the coil go open to current flow.

[@davessmallenginerevival2847]

Very good Bruce. My fingers crack like yours. I guess I haven't figured out how to use gloves yet ha ha

[@BrucesShop]

Well the carb spray just ruins them in seconds but I try to use them.

[@rogeroconnor5182]

nice when things go as planned,you can relax for awhile from all those mowers that gave you heck!

[@BrucesShop]

Yes you got it. I fix the flimsy hood next week I hope

[@jerryf2426]

Bruce use O'Keeffe's Working Hands at night and seal the cut with super glue the next morning with washed dried hands. This keeps the wond from continually cracking open. Heals fast.

[@BrucesShop]

Thanks Jerry sometimes the hurt.

[@SouthpawDavey]

i envy you organization Bruce. And great information. Thanks Mate.

[@BrucesShop]

The organisation does take time though.

[@carlcap14911]

Bruce have you ever considered getting a ultrasonic cleaner for cleaning carburetors and other small items? You just put the items in the ultrasonic cleaner container and leave it there for about 15 to 20 minutes and presto it's clean!

[@BrucesShop]

Christmas is coming!!!

[@geojor]

thanks Bruce ...

[@nashguy207]

Good job Bruce. The stx38 is one of my least favorite lawn tractors john deere ever made. The engines were ok its the rest of the mower that wasn't up to the quality of typical john deeres back then. My neighbor bought one and had a lot of problems with his I was always fixing stuff on it the deck and the linkages weren't very good. The LX178 in the background of this video. Is it a kawasaki water cooled engine?

[@BrucesShop]

I agree with you The stx38 is not put together very well. The Lx178 (mine) is a little hot rod. Compression of 10-1 and liquid cooled. Good for dusty stuff.

[@nashguy207]

Yes I agree about the LX178 I have one inherited it from my father in law. The great mowers with the kawasaki water cooled engine. They do have a lot of power.

[@BrucesShop]

Thanks Mr. Nash

[@40ounce58]

Great video Bruce!

[@BrucesShop]

Thanks sir

[@rickg4802]

Hello Bruce, I have something of a quandary. I am working on this Craftsman 6.75 HP with a Briggs and Stratton engine. I have cleaned the carb twice, put a new primer bulb on and tested the bulb. No fuel coming into carb. Put a second gasket on the breather housing (2), still no fuel being sprayed into the carb. I sprayed starting fluid into the carb and the engine runs and will continue to run until I shut it off. Any ideas on what might be causing this? Thanks for your input. Rick

[@BrucesShop]

Is the red primer bulb cracked around the hole. That has gotten me as there was no finger seal.

[@Jake-lr8zy]

kzbin.info/www/bejne/o36oqoCmhs2Ajac Bruce Pender's Video: The Little Things Can Fool You (Lawnmower with briggs) Also, is the air filter housing warped?

[@BrucesShop]

Thanks Jake

[@kevinsanders6236]

well done bruce.

[@BrucesShop]

Thanks Kevin.

[@peterhouben3753]

Use heal balm for cracked skin ,on your hands works a treat. Peter

[@BrucesShop]

I use Dawn dish-washing detergent.

[@rickg4802]

It is a new red primer bulb. It has no cracks. The primer bulb was seated in the white housing before I snapped it into place. I used a socket to snap it in place. Again, Thank you. Rick.

[@BrucesShop]

The carb bowl seal also helps to seal the air pulse. just trying to help. I hope that is OK.

[@rickg4802]

Bruce Pender It is absolutely OK. I need all the help I can get. I will replace the bowl gasket and see what happens. Thanks. You not only help people by repairing their equipment, you also help people with you knowledge. I like the details in your videos.

[@Budro4764]

Is it the bulb with the hole in the middle of it ?? If not, you have put a 3.5 HP bulb on it. Wrong one.... Always when taking a bulb out spray carb cleaner in the hole to clean the passage way out that is molded in the air box......... There is a screen in there also. That has to be free of varnish/gunk also..... Note where the gasket is line up on the carb body and make sure that hole is not clogged up also.... It is a very small hole and is often overlooked..... Hope this helps Mon Ami..............

[@rickg4802]

Boo LuQuette Yes it has a hole in the center of the bulb. I used my air compressor to blow out the screen inside the filter housing. I will have to use carb cleaner on the screen. Not sure if I am thinking about the same hole as you, but on each side of the carb where the filter housing screws go, just to the inside of the carb is a small hole on each side. I sprayed them with carb cleaner. I also tried to get a very small wire poked into those holes to no avail. The wire was probably the size of a bread tie wire and that was to big. I also blew them out with air. Thank you for your input.

[@Budro4764]

Ok sounds like you have covered all 3 bases so far, but haven't made it to home base yet to score a run. I haven't made a short vid yet on that subject , but I will in a few minutes. I need to go in my shop and get a few things.. Stand by for about 30 minutes...........

[@sperrytops]

Awesome video!!! Keep it up...

[@BrucesShop]

Thanks Joey.

[@lenscap8925]

Best piece of advice I got from the lawn mower mechanic (after the bill was paid) was to run the carb bowl dry by turning off the gas at the tank. Pressure on seat is too high when sitting with gas in tank and heat

[@BrucesShop]

I do that to. thanks

[@henningbergmann5494]

Love this

[@BrucesShop]

Thank you

[@jimw7916]

I prefer "Zed" over "Zee" hahaha

[@BrucesShop]

Right. Thanks for the comment.

[@patrickderp1044]

when you run out of mustie1 there is... BRUUUUUCE PENDER

[@BrucesShop]

haha Bruce here.

[@toroon]

Any snowblowers yet? Just put the lawnmower away. A sad day indeed. Oh well, next years weeds await!

[@BrucesShop]

Yes they are lined up now.