ebinmaine 67,423 #1 Posted May 19, 2018 We have a pro-made non name-brand log splitter. Built by a logger, for splitting big butt end stumps. The engine is a 6.5 horse Briggs and Stratton industrial/commercial. The engine will only run right and smooth if the choke is half closed. Also, it doesn't like to run below about 1/2 throttle much at all. That doesn't matter to awful much because it's always at or near full throttle in operation. If it's put to full open choke it runs very erratically..... Up/down... Up/down...Up/down...Up/down... I took apart the carb and cleaned it out by spraying all through with Berrymans B12, reassembled with new gaskets, float needle. It's a bit more even but still won't run right unless at half choke. Does it really matter at all if it's happy running that way? Share this post Link to post Share on other sites
953 nut 55,189 #2 Posted May 19, 2018 If you are closing the choke at all you are reducing the air flow and an internal combustion engine is essentially an air pump. Reduced air flow results in reduced power. There is fuel starvation and a good soaking and blowing out all passages should do the trick. 1 Share this post Link to post Share on other sites
ebinmaine 67,423 #3 Posted May 19, 2018 14 minutes ago, 953 nut said: Reduced air flow results in reduced power. There is fuel starvation That's what I was thinking too. If the splitter runs fine although at half choke... And has plenty of power..... Does it do any harm to leave it the way it is? Share this post Link to post Share on other sites
JoeM 7,873 #4 Posted May 20, 2018 EB if I am thinking right, there are a couple of small ports in the in the bowl nut. I've had to stick a fine wire through them to correct the same problem. I tried just spraying, but that didn't work. Now, I make using that wire as a practice on all the ports. ??? 1 Share this post Link to post Share on other sites
ebinmaine 67,423 #5 Posted May 20, 2018 35 minutes ago, OILUJ52 said: if I am thinking right, there are a couple of small ports in the in the bowl nut. Yep you're right. I did spray them but I'll try the wire tomorrow. Share this post Link to post Share on other sites
Digger 66 3,478 #6 Posted May 20, 2018 9 hours ago, ebinmaine said: I took apart the carb and cleaned it out by spraying all through with Berrymans B12, reassembled with new gaskets, float needle. Was the carb really gummed up when you tore it apart ? If so ( as stated above ) the main may still be full of crud . I'm not a big fan of sticking a steel wire into a brass main . I would opt for a good soaking then a few blasts of carb cleaner followed by compressed air . 2 Share this post Link to post Share on other sites
ebinmaine 67,423 #7 Posted May 20, 2018 1 hour ago, Digger 66 said: Was the carb really gummed up when you tore it apart ? That's the thing.... It really wasn't to bad. I'll take another look at the main jet bolt though. 1 Share this post Link to post Share on other sites
squonk 41,067 #8 Posted May 20, 2018 Running an engine under load with a leaned out mixture can overheat it and damage pistons and valves. 1 1 Share this post Link to post Share on other sites
ebinmaine 67,423 #9 Posted May 20, 2018 Did some poking around online and it seems this carb is known for NOT being repaired with a good cleaning. I found several posts indicating 2 or more cleanings and then still not fixed so it was replaced and problem solved. Aluminum throw away carb and P.O. ethanol usage. Oh well..... Fleabay here I come... 1 Share this post Link to post Share on other sites
oldredrider 2,548 #10 Posted May 20, 2018 I had one of the Briggs do the same thing. Cleaned it until it was spotless...several times. Never would run right. Finally put a new carb on it and problem solved. Odd part is, I saved the bad carb and ended up trying it on another Briggs that needed a carb. It ran perfectly on that motor. Mystery I never have figured out. 1 Share this post Link to post Share on other sites
tunahead72 2,412 #11 Posted May 20, 2018 Don't give up on the bowl nut idea. Poking those holes with a very fine wire has solved poor running problems on several B&S engines for me recently. You can find carb wire kits online at motorcycle parts places if nowhere else. Share this post Link to post Share on other sites
ebinmaine 67,423 #12 Posted May 20, 2018 1 minute ago, tunahead72 said: carb wire kits Would a Very fine mechanic wire or a very small wire drill work? 1 Share this post Link to post Share on other sites
wallfish 16,994 #13 Posted May 20, 2018 6 minutes ago, ebinmaine said: Would a Very fine mechanic wire or a very small wire drill work? Cut a piece of electric wire. The braided type and unravel a single piece out of the braid. Different gauge wire has different size pieces of braid and you probably have some hanging around the house anyway. Plus it's copper and not as hard as steel wire and you can make it as long or short as needed. Works for me 4 Share this post Link to post Share on other sites
diesel cowboy 263 #14 Posted May 20, 2018 or I've used the paper coated twist ties from a loaf of bread. It's a small piece of soft wire inside. Just strip some paper off one end and leave it on the rest so there's a little more surface area to hold than just the wire Share this post Link to post Share on other sites
wallfish 16,994 #15 Posted May 20, 2018 3 hours ago, diesel cowboy said: or I've used the paper coated twist ties from a loaf of bread Oh yeah, used those before too. They also make good jumpers for a blown fuse. Small enough to burn up if there's real short but sturdy enough to get you home. Share this post Link to post Share on other sites
Sarge 3,463 #16 Posted May 22, 2018 I just went through 5 Briggs carbs last weekend, all had the main fuel feed holes in the plug filled solid from ethanol use. A lot of damage to the casting itself as well - all cleaned with a common welding torch cleaning wire tool. These are used to clean the various openings on cutting torch heads, available at nearly any farm or welding store, cheap. Just a simple set of wires 2"-3" long with spiral teeth on them and a piloted end that is smaller, generally. They work great on carbs but be careful on brass jets and aluminum ports - too much cleaning can change the original bore size and screw them up. Ethanol erosion is the culprit on the newer carbs, hence the required replacement. The manufacturers have now set them with fixed jetting per the emissions rules to a very fine point - one slight alteration from that and they run like crap - almost no level of cleaning will fix them, either. I'd like to patrol the local stations and hunt for all the folks using ethanol in small engines - then beat them with the gas pump hose nozzle as a lesson...I hate having to fix the damage from the stuff. Sarge 1 Share this post Link to post Share on other sites
ebinmaine 67,423 #17 Posted May 22, 2018 6 hours ago, Sarge said: A lot of damage to the casting itself as well - I did check the bowl bolt/Jerry and I think my issue may be up in the casting. Hence.... I'll order a replacement carb. Share this post Link to post Share on other sites