Kelly 1,028 #1 Posted May 29, 2008 I have a 656, nice tractor, but the carb is giving me fits . I've put 4 diff. carbs on it none better than the rest, till today, I pulled one at the junk yard, cleaned it, changed the needle and float and bowl gasket, got it to run pretty good, not great but didn't need the choke on full to run and I could rev it up couldn't do that before , but the more it ran the more it needs the choke set 1 notch . I completely rebuilt the orig. carb only to make it worse than it was before I pulled the welsh plug and cleaned the 3 little holes and all the rod that you can't get to, can't remember the name of it, moves freely when you shake the carb. act's like I have a vac leak, or not enough fuel, probably that. Any help on these carbs would be great, This is a very nice tractor just needs to run better. Share this post Link to post Share on other sites
Kelly 1,028 #2 Posted May 29, 2008 and no a big hammer is not the answer Share this post Link to post Share on other sites
sorekiwi 761 #3 Posted May 29, 2008 Well, I'm no expert as I'm still not real happy with the carb on my 502, but I have had that one apart about 20 times so far... The biggest gain I've had so far was by cleaning the passage that the rod you are talking about is in. Mine was free enough to rattle, but when I broke down and removed it there was a lot of crud in that passage. I drilled out the plug on the bottom, cleaned it all out, and spun up a new brass plug that was an interference fit to seal it back up again. The other trap on these early carbs is that you are not supposed to remove the main jet, as it is installed at the factory, then a hole is drilled through the side. If you remove the main jet and reinstall it, then this hole will almost certainly not line up with the hole in the casting. The fix here is to turn a narrow groove around the main jet, at the height of the hole to allow the fuel (air? - dont remember) to get to the hole. Its hard to find tech info on the early Tecumsehs, the best source I have found is here: http://www.perr.com/forum/ But I have been tempted to get the big hammer out... Hope this helps Share this post Link to post Share on other sites
sorekiwi 761 #4 Posted May 29, 2008 Another thought.... Are you using a fuel pump? Mine was gravity fed, as the old pulse pump was missing. I havent found an origional one yet, so in the meantime I'm using a Briggs pulse pump. It definately helped a bit. I can probably find the part number if you need it. And yes it does look completely wrong on the tractor... Share this post Link to post Share on other sites
Kelly 1,028 #5 Posted May 30, 2008 Is this the part you are saying cut a groove around? the bottom hole? the top hole is in the upper groove very small hole. and yes it is gravity feed, looks like it never had a pump of any kind. Share this post Link to post Share on other sites
sorekiwi 761 #6 Posted May 30, 2008 Is this the part you are saying cut a groove around? the bottom hole? the top hole is in the upper groove very small hole. and yes it is gravity feed, looks like it never had a pump of any kind. No, thats the one in the bottom of the bowl. I'm talking about the brass jet that goes up the middle of the main carb casting. (its the piece above the bit you posted a picture of). I had a photo at one stage but of course I cant find it now. There is a drawing of it on page 18 of the L Series manual (diagram 35) that shows a standard jet (no groove) and a service jet (with groove). You want to copy the service jet by machining a groove around the standard jet. (Note: you only need to do this if the jet has been removed from the carb - the factory drilled the hole in the side once the jet was installed, so removing the jet screws up the alignment of the hole in the carb with the hole in the jet. I hope this makes sense!) Here's a picture of a pulse fuel pump on a 552. I dont know, but I thought your engine would have something similar? I was wrong about the pump I'm using, it's a Honda part: Mine is black, not white, plastic. Share this post Link to post Share on other sites
kpinnc 10,686 #7 Posted May 30, 2008 I put a Kohler carb on my L-157. It works great! Kevin Share this post Link to post Share on other sites
sorekiwi 761 #8 Posted May 30, 2008 Found a picture! You can see the hole drilled up in the threaded part of the jet. If you remove the jet then you need a groove around this part to enable fuel to get to this hole. You could probably do it with a carbide bit in a dremel or something, I did it (very carefully!) in the lathe. Brass can be a bit tricky sometimes and want to grab the lathe tool. Share this post Link to post Share on other sites
