Amazon carburetors

[John2189 521]

I thought I read that some amazon carbs needed a hole drilled out?  I did a search, but couldn’t find it 

[wallfish 17,772]

What carb/engine type are we discussing here?

Why can't the original carb be serviced/rebuilt and used?

[John2189 521]

12 hours ago, wallfish said:

What carb/engine type are we discussing here?

Why can't the original carb be serviced/rebuilt and used?

Its on a k341. Don’t have the original carb.  The tractor was given to me a few years ago. It had a thrown rod. The carb was not with it, so I bought one from amazon. Anyway the engine runs very rough and runs hot. 

[pfrederi 18,520]

Hot usually means too lean a mixture.  Cheap cabs sometimes show up with dirt blocking passages.  Check the main needle.

[John2189 521]

Ok thanks I’ll take it apart to see if it is blocked. 
when I do try to adjust, it doesn’t make very much difference 

[oldlineman 1,510]

better off picking up a good OEM and rebuilding it. Cheaper in the long run

[953 nut 58,979]

These universal one size fits all carburetors don't actually fit anything properly. I bought one years back and found that the body was for a 10 or 12 HP Kohler (# 26) but was jetted for a 14 or 16 HP Kohler. It wouldn't work well on either size engine.  As others have said, find a used  OEM Carter # 30 and rebuild it.

[Wild Bill 633 869]

My experience with China carbs is you always get a little extra inside. Machining chips that is.

[GAJoe 852]

On 5/18/2025 at 8:49 AM, Wild Bill 633 said:

My experience with China carbs is you always get a little extra inside. Machining chips that is.

There's a YouTube video where the guy removes the bowls from several knock-off carbs and shows how much metal shavings he gets out by simply tapping them on a dark glossy surface. 

I've seen a ton of questions on other forums where the OP is asking for help with one of these China knockoffs. Until there's a list of which ones have demonstrated reasonable quality control and dependability then the problem is fixed by removing the China junk. Their price alone gets them enough sales that they don't have a great deal of incentive to improve their quality. I bought a Snapper RER that had one of these on it causing a flooding condition without a load. I did a rebuild on it that was mostly "O" rings that helped some. The main jet 's tiny O ring was hard as a rock. But still the flooding while no load was happening. Start mowing and all sounds great. The idle stops flooding and sounds good when I close the in-line gas valve, until it runs out of gas. I always kill it by closing the gas valve and let it empty the carb.  I contacted the seller of the Snapper and asked what he did with the Walbro that was on it. He said that the bowl had a hole in it so he threw it away and got the China knockoff. Said that the price was right.. 

On 5/18/2025 at 7:46 AM, 953 nut said:

These universal one size fits all carburetors don't actually fit anything properly. I bought one years back and found that the body was for a 10 or 12 HP Kohler (# 26) but was jetted for a 14 or 16 HP Kohler. It wouldn't work well on either size engine.  As others have said, find a used  OEM Carter # 30 and rebuild it.

 

I did find a "new-old stock", genuine B&S OEM carb, new, in the box B&S# 799728 on Ebay for $40 so I bought it. It's got both the B&S emblem and "Nikki" in the casting. They were $120 back in the day. I'll put a Viton O ring on the main jet and cross my fingers. I'm hoping that the Japanese Nikki carbs had good quality control. From what I read they are what B&S had to go to to meet EPA regs for cleaner air and not adjustable. I'll try to remember to report back on how it does.

 

I was looking for a Walbro, even if it was on a blown up motor for a good price, and found a B&S 12.5HP I/C Quiet with recoil for $75. The motor isn't locked up and shows 68psi compression when I put 12 volts to the starter after changing the oil.

 

The Walbro needed a good cleaning. I stripped the slot on the imulsion tube and have spent a lot of time trying to get it clean still in the carb. We'll see if my efforts were successful. I'm waiting on the parts to complete the rebuild and find out. I wouldn't have bought those parts if I hadn't seen evidence of my cleaning working without going into detail and making the post even longer. Again " I'll try to remember to report back on how it does." 

 

Do y'all think that I should check the valve clearances and the cylinder condition before trying to start it? I've had guys say "Just run it and see how it runs and sounds." But I added the head gasket, breather gasket, and exhaust gasket  to my carb' parts order so that I can. I think that I will. If it runs good when I finish I'll replace the black 10HP with the matching 12.5HP and keep the 10HP for backup. It starts aufully easy.

Edited May 20 by GAJoe
spelling error

[Handy Don 13,576]

Vanishingly few buyers will spent $X for a demonstrably high quality carb that would give 15+ years of service with little trouble when a toss-the-dice option for one quarter of $X is available. 

Personally, I’ve bought and used aftermarket carbs (and pre-cleaned them) with 75% success (3 good, 1 fail) but I’ve gone in with my eyes open and knowing the risks. 

There just isn’t a sustainable business model/market for high quality parts. 

[Razorback 1,090]

I need to replace the carb on my Speedex 1631. OEM Briggs carb is crazy expensive, but I have decided that I WILL save up and order one.

Edited May 22 by Razorback
Fix a spelling error

[GAJoe 852]

On 5/19/2025 at 8:56 PM, GAJoe said:

I did find a "new-old stock", genuine B&S OEM carb, new, in the box B&S# 799728 on Ebay for $40 so I bought it. It's got both the B&S emblem and "Nikki" in the casting. They were $120 back in the day. I'll put a Viton O ring on the main jet and cross my fingers.

 

Update on the Nikki carb.

I replaced the two O rings that usually fail and result in flooding with Viton O rings and installed a better fuel filter to hopefully avoid problems. I replaced the Chinese carb with the new B&S OEM and made sure that the governor was set properly. I started it and let it warm up. The surging problem is gone . When I lowered my throttle to minimum setting it died so I got my tachometer and adjusted my idle speed screw to 1750 RPM. The tachometer shows that it is running about 3100 RPM at max throttle. Correct me if I am wrong, that RPM is controlled/adjusted by the tension of the spring on the governor. I could bend the tab to change that, correct?
My main question is about adjusting the fuel/air mixture jet setting. I have been unable to find that proceedure anywhere. The engine origionally had a Walbro LMT carb I do believe as the service manual that I downloaded doesn't have the proceedure for a Nikki made carb. I am refering to B&S SM 270962 Single Cyl L-Head Sec03 Carburetion. I did find the LMT instructions on pages 47 & 48. Would this same proceedure work for the Nikki?

 

 

Edited May 24 by GAJoe