Best Diaphragm Carb ?

There are several good diaphram carbs out there, most are used on chainsaws. McCoulloch used Walbro and Tillotson, Homelite used Mikunis and Zumas. Early Tecumseh engines used on snowblowers like Ariens also used a good reliable diaphram carb. I have used them all but like the Mikunis and Tecumseh best. They are readily available and can be had for not much money. My tecumseh carb works equally well on a 2-stroke or 4-stroke of comparable size. Hope this helps.

Well, Otero, I have two of these carbs and they are identical except one is set up for a primer bulb which you will need if you aren't using a gravity fed fuel tank. That carb is #47 411, I'm sure that's an obsolete number. It came off of a 3.5HP Tecumseh 2-stroker, model #THO98SA, or TH139SA, or TH139SP. There are three versions of this same engine, one has a 12 volt electric starter, one has a 115 electric starter, and the third is pull start only. You can cross reference the carbs you are looking at to these engine model numbers. The non-primer bulb carb came off of a 3HP Briggs and Stratton 4-stroke engine on a lawn edger. These carbs don't care if they are hung on a 2 stroke or a 4 stroke, they work great on both!!!!! If you purchase a used one you might want to consider getting a rebuild kit. The diaphrams get hard and crack over time and crud builds up on the innerds, especially now that ethaol is so prevalent. Rebuild kits are cheap and I just installed one in about an hour last week. Good luck.

These carbs have such small orifices that any coagulation or varnish is going to clog them. I usually put stabilizer in my premix and my regular gasoline. Then every 6 months or so I put a capfull of gumout in the tank to rinse out the crud out while I'm riding. The engine doesn't run quite as well on that tankfull, but it keeps her going in the long run. The carb I rebuilt last week had been on the shelf for a couple of years. Apparently I left some gas in it when I took it off the snowblower engine and varnish crystals built up on the diaphram itself. I cleaned that then sprayed brake cleaner through the channels using one of those tiny plastic hoses that comes with WD-40, then blew the channels out with compressed air using a basketball inflator needle. She works like new.