Tecumseh 640266 (640288) Detailed Carb Clean [4K]

In this video I show you in detail how to clean a Tecumseh carburetor from a lawnmower. I also end up having to jet this carb as well (drill the jet). This video shows specifically the 640266 carburetor, but it applies to many other Tecumseh lawn mower carburetors. Similar carburetors would be: 640288 640118.

Carburetor Rebuild Kit: 632760B
Emulsion Tube O-Rings: 632547
Bowl Gasket: 631028A
Bowl Nut/Jet Gasket: 27110A

[RichardNavarrete]

This helped me so much today. Thank you for adding the details about part numbers, sizes of tools. And thank you for not skipping critical segments like assembly, cleaning tiny screw holes... It made all the difference.

[cassandra]

Great video! I had the exact same problem with the bowl gasket. I couldn’t figure out the issue until your video explained it and showed how to fix it. Thank you so much!

[wm]

Good stuff thank you. I’ve learned a lot just by watching. My Grandson Loves your videos also. 👍🏼

[robcole]

Well I just subscribed after seeing you replace that seat and drill out the jet. Felt you know what your doing. Some in here that do videos don’t have a clue and it aggravates the hell out of us that do have a clue lol. Great video

[benjamincresswell]

A penny for your thoughts: I bought a brand new lawn mower at Rural King in the fall of 2023 called a Pulsar 21''. It's got a 199 cc 4 cycle engine on it and it was on sale for $99. I mowed with it about 5 times last fall and it worked very well for a dirt cheap mower. But when l stopped mowing for the year, I didn't dump the gas out of it. In the spring this year after filling it with fresh gas it didn't want to keep running. There is no choke, no adjustable throttle, just a primer bubble and the bail controlled on/ off switch. I put about 1 ounce of Chevron Techron Fuel Injection system cleaner into the full gas tank of mostly fresh gas and after priming it a few times to keep it going, it seemed to straighten right up and I was able to mow the lawn. I have mowed the lawn at least 15 times since with no noticeable problem. But just Monday, 05AUG24, on a cold start, it began to act up again. So again I put about 1 ounce of Techron into the full tank of fresh gas and after pumping the primer between 50 and100 times to keep it running, it finally began to run well enough to mow the grass. I was able to mow about 1/3 of the yard, about an hour or so, befor it began to act up again. Now it's struggling in the taller grass, going to WOT, slowing down and then recovering. It does OK in the lower grass. I know it's starving for fuel and if it had a choke I'd simply put the choke on partly.*(my snow blower has always had to have the choke on partly to keep it from hunting/ surging since brand new) I am wondering what the Techron was clearing? Is there something that you know of? Why was Techron able to resolve the problem early this spring, and for an hour or so here in mid summer, but doesn't seem to be able to clear it up completely this time? Is it something in the gas? It's fresh gas, bought about 2 weeks ago, and it's the same gas I burn in my truck (2017) I am about to rip the carb down and drill out the main orifice, but I am wondering what the root cause of the problem is. What is in there that is restricting the fuel that the Techron was able to clear? I do not believe it is water, because I do not believe the Techron would have fixed it. Maybe I'm wrong, do you know? I have a full set of numbers letters and fraction drills and it's not beneath me to figure out what size the main discharge orifice is and then open it up a couple thou, but I just wonder what's causing the leaning that the Techron was able to fix in the spring, and for about an hour again just yesterday? I wonder if after I open it up if it will again lean out. If you care to, you may respond to moparbens @ yahoo dot com please. ben/ michigan.

[rufusmedrano]

I’m glad you made the wise decision to change the bowel gasket

[daveschidlmeier]

Excellent through detailed video. I would have never seen some of them very small jet holes on the idle jetting.
The 6.5 HP mower is now an easy start and runs like new.
Very informative video . Thanks for posting it.
Good Job !!!

[joannaking]

Your video helped me bring my mower back to life. Thank you so much. I was dealing with gas pouring out of the carburetor.

[ozseymen]

Perfect explanation with clear scenes. Thanks a lot.

[johnlocker]

An easy test for a brass float. Make a cup of HOT WATER. Now put the brass float into hot water. If there is a leak you will see bubbles coming out of the float. No bubbles, you are all set. Bubbles you can solder the hole.

[Warpedsmac]

That original needle seat was installed upside down...wrongly....the grooves face inward to carb.

[geo]

Hi bill can you install new float and pin on carb installed on mower?

[synergyacousticcovers]

How do I identify all the same component parts you reference for a Tecumseh Carb 640052. Have the same issue w/ the needle seat on a snowblower. And emulsion tube o rings are shot. Thx!

[dougsorensen]

You showed the Tucumseh tool trying to get the o-ring out. It is also for measuring the float height which is easily adjusted?

[Sheeeeeeeeeeeeiiitt]

Regarding the idle air restrictor jet…Is there some sort of spring/ball built within top hole of the jet? For instance when I cleaned the bowl nut passages (you can stick the wire through the center passage hole and see it from the side passage holes).

Also when screwing the jet back in should I put the cap back on and seal it with nail polish? Thanks for sharing this video it was very helpful.

[jarosawdomanski]

I have had a problem for a long time. The engine is still working irregularly (higher and lower revs) like yours before improving the hole with a drill.
What diameter drill bit did you use at the end of the video to correct the hole? Unfortunately, I can't understand because I don't speak fluent English.
Best regards from Poland!

[thuswaldner]

I think it is better to remove the bowl gasket before cleaning so you can get all of the metal surfaces

[drcajundan]

Did you put emulsion tube back in correctly? I think you put it in reversed...

[Pushyhog]

your really mild bill, not to wild. ya think?

[eathans_small_engines]

How many turns in is your air-fuel jet