Jump to content
Oldman

Tecumseh Enduro-640025 OHH55 OHH60 OHH65

Recommended Posts

Posted (edited)

Hello,

I installed a carb on a small craftsman generator with Tecumseh Enduro 5.5hp LotFancy 12U-2760-D. The engine ran excellent. Shut off and set, no leaks. Presumed everything is fine. Next day the bulb had a hole and gas appeared to have melted through? The needle & seat must have failed as well as there was gas coming out the air intake? I found a rebuild kit Oregen 49-427 and Napa carries the primer bulb SME 704950. Hoping Napa's bulb will be quality.

Any help greatly appreciated.Has anyone else bothered to rebuild this aftermarket carb?

 

Regards, Oldman

IMG_2499.JPG

tecumseh-LotFancy 12U-2760-D.jpg

Edited by Oldman

Share this post


Link to post
Share on other sites

Do you have a photo of what you need. I probably have some old ones around here if you cant find one.. That system is problematic. I install a fuel shutoff in the machines that have that type of seat.

  • Excellent 1

Share this post


Link to post
Share on other sites
Posted (edited)

Hello,

      I can get a picture then the original carb Tecumseh 640017 Series 8 which didn't use the brass seat. (I never cared for the set-up with the rubber tipped needle). A fuel shut-off would be tight under that tank.

 

 

    Regards,

    Oldman

Enduro 2500.pdf

Edited by Oldman

Share this post


Link to post
Share on other sites
17 minutes ago, Desko said:

Hello,

    no they have 640017B in stock and it is 78.00, slightly different could be tweaked. The 640017 is out of stock at 46.50, must be OEM? Nice site as I used them before, I see a few of the other components there, which is nice.

 

Oldman

Share this post


Link to post
Share on other sites
13 minutes ago, Oldman said:

Hello,

      I can get a picture then the original carb Tecumseh 640017 Series 8 which didn't use the brass seat. (I never cared for the set-up with the rubber tipped needle). A fuel shut-off would be tight under that tank.

 

 

    Regards,

    Oldman

Enduro 2500.pdf

If you just take a photo of the parts you need ill check if i have them here. Its worth a shot may seal better than what you have. Meanwhile the fuel shutoff will work.

Share this post


Link to post
Share on other sites

I believe the 640017B is the updated kit and the other is oem either or should work though but don't exactly quote me on that its been awhile since I've worked on a tecky 

Share this post


Link to post
Share on other sites

I see the photo. Let me look. Pretty sure I may have the needle and perhaps the seat.

Share this post


Link to post
Share on other sites

Looked but to no avail. I have some like the one in photo but no rubber tip.

Those carburetors used to drive me insane also with the same problem. Only when i read the excerpt that i attach below from Brian's Miller site did I understand the problem and why it happens. To further substantiate his comments a snowblower usually does not have a fuels filter. So I started following his advice and haven't had a leaky walbro in years.

 

The older Walbro WHG #52, #60 and #64 carburetors are reliable and they seem to last a long time before requiring service. Most older Walbros are worth rebuilding, because the float valve seats are made of hardened solid bronze, which is actually harder than cast iron. They were manufactured back in the day when most business owners took pride in their products and offered their customers a quality product.

But the newer Walbro carburetors, especially the ones that come on recently-built aluminum block small air-cooled engines, are notorious for leaking gas after several years of use. Although overhaul/rebuild carburetor kits are available, it really does no good to rebuild them and install a new fuel inlet valve because the float valve seat is made of soft brass, which erodes with use due to microscopic particles of dirt/debris that pass through the filtering material in the fuel filter, and in most Walbro carburetors, the seat is not replaceable. The fuel inlet seat in older Walbro carburetors are made of hardened compressed bronze, which is actually harder than cast iron. There is no indication or records of when Walbro made the change from the hard seat to the soft seat.

The filtering material in fuel filters can only filter out so small of particles of dirt/debris. Any heavy particles that can pass through the filter will build up in the bottom of the float bowl and can eventually clog the main jet. Lightweight and suspended particles gets sucked up through the main jet and is burned in the combustion chamber. On very rare occasions, a hair can pass through the filter and become lodged in the float valve fuel inlet seat, causing the carburetor to flood with gas. When this happens, the hair can be removed with [150± psi] compressed air and the same float valve and seat can be reused.

To put it in plain English: If your Walbro carburetor doesn't leak gas out the choke end, but need an overhaul/rebuild, then it may be worthwhile to install a new kit. But if it does leak gas, then I doubt that a new float valve will fix the problem. Your only options are: install a fuel shut-off valve and turn off the fuel every time the engine is not in use, or install a rebuilt Carter/Kohler K-series carburetor.

About 90% of small engine carburetors are made by Walbro nowadays, and I don't think that one is better than the other. The trick to getting the soft brass seat (and needle/float valve) to last longer is to use a fuel filter with a very fine mesh or pleated paper element. The finer, the better. Because it's the microscopic dirt/debris/grit that passes through the filter that causes the seat (and needle/float valve) to erode and wear. And every pressed-in brass seat that I've replaced ALWAYS leaked gas. There's just no way to get them to seal with the carburetor body, not even with high strength liquid thread locker.

If a Walbro carburetor drips fuel, and a new carburetor is out of the question, the only options is to either install an under-the-[gas] tank or in-line fuel shut off valve (lots of people do this). Or a new carburetor can be purchased, and hope the leaking fuel situation doesn't happen again in a few years. (Walbro is like Walmart or Sam's Club, they want 'em keep coming back. This undoubtedly is how many world-wide, major businesses nowadays keep selling new high-dollar replacement Chinese-made carburetors and other engine parts to unknowing or ignorant customers.)

  • Excellent 1

Share this post


Link to post
Share on other sites
Posted (edited)

Hello,

    I totally agree. I also enjoyed the read. Oh, and thank you for looking for the needle valve. There is a kit out there for this needle & float ( Oregon 49-427 / Rotary 13271 ). As you know after market. I had always steered clear of "aftermarket" anything. The brand new china carbs work even if temporary, how-be-it, engineered with sub-par components. I was sent replacements but they sit in the box. There are only a couple of parts that can be salvaged from these "clones". A-1 Miller is a great site and Brian is a genius for sure. I have two LM Tecumseh and two HM. Gas inlet on opposite side of the carb. I even have the replacement main jets genuine Tecumseh. I have done everything known to man & mechanic to use these carbs to no avail. Now they sit on my shelf. OH series Tecumseh are very strange for the earliest OHV Engines I'm aware of? This little Enduro Generator is about useless anyways. I can run a few lights or a power tool in the field, that's it, (2500 watts). I rebuilt the factory 640017 and have yet to even start it up, pretty sure it will run fine. Now there is the 8hp Briggs with updraft carb which is known to be "almost" impossible to prevent leakage while not in use, this has a fuel shut off. A mouse resided under the shroud and urinated unto the condenser & points! I removed the condenser and cleaned the housing, then tested the coil, (as the mouse gnawed on the condenser lead shielding), a nice piece of antique rubber shrink wrap fixed that. I will use the Nova Chip to replace the condenser, looking for a nice spot to mount and ground the chip. This Homelite puts out 3500 watts and a true 240 volts. Now this is a bear to start as the compression is incredible off the pull start! Installing a stater and flywheel ring gear with electric starter is extreme and costly. (12v system & battery) I only keep these items functioning for the emergency situation so they sit for years at a time.

I think I do this for the challenge, (making the garbage components function) due to the unforeseen future and lack of OEM. Realist? I really appreciate your input. Again, thanks for looking for the needle.

 

Regards,

Oldman

tecumseh-LotFancy 12U-2760-D.jpg

Edited by Oldman

Share this post


Link to post
Share on other sites

The shut off valves seems like the sensible solution.  My 3 old farm tractors all have fuel tanks above the engine, gravity feed no pumps.  I always shut off the fuel when I shut them down.  The glass fuel filter bowls always had shut offs just for that reason.

Share this post


Link to post
Share on other sites

I've grafted other engine carbs onto a lot of Techy motors over the years for that very reason and I'm with @formariz - the older bronze seat models were far superior and worth rebuilding. In the past, I actually ground the seat when they started leaking and used a rubber tipped needle to fix the issue - but they never lasted all that long due to the issue of that soft seat so those engines got a like-sized carb off another engine. Even modified some of the older Briggs engine carbs to work on the Techy's - it took a lot of work to make the throttle and choke work correctly but they ran excellent and stopped leaking. This practice of building equipment to "just barely good enough" is why I buy very little new equipment - I'd rather have something that is 30yrs old and repairable instead of disposable junk.

 

 

Sarge

  • Excellent 1

Share this post


Link to post
Share on other sites

It used to drive me completely insane that these things would leak and many times I had also done a Carter or a Kohler carburetor at the same time and those would never leak. I knew then that it could not be something I did wrong.

Still related but on a slightly different note, another thing that always frustrated me was the carburetors on snowblowers. Again Walbro's. Most snowblowers that I hear are not running correctly. Most are surging. There is no way to adjust them since they have a fixed jet. After buying a Chinese knockoff for mine and being disgusted with the results since it started surging also before the end of the season I adapted a regular carburetor to it with high and low speed adjustments, and guess what? It runs correctly 99% of the time. When it varies a little probably because of the weather a little turn of the high speed adjustment and its perfect again. Also put a fuel filter in it. Since then no more frustration with the blower.

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Recently Browsing   0 members

    No registered users viewing this page.

×