Torrence20 19 #1 Posted October 21, 2018 So I’ve got. 310-8 it has the 10 hp magnum. Once the motor runs great. Smokes until warm then it stops if it take it from idle to full throttle without feathering it slowly it pops bangs backfires etc. so I pull the choke out quickly and push it rite back in then it smoothes out and runs great. If I have a good load on and am pulling a big hill once it bogs down it will stumble as well not nearly as violent and it then smooths out with no help from the choke. When I first got thise unit it wasn’t running had old gas in it. I drained the system blew out the tank put new fuel line and filter on removed the shitoff and took the little filter off of it reinstalled with a new tank bushing,pulled the carb cleaned and cleaned it... it was very gummed up. Not a lot of corrosion just varnish and thick jelly like goop it ran great after I did all that. After some run time it began all of this and I also noticed the fuel filter was running about half full at first now there is nothing in it I can watch closely and see the fuel going thru it but there isn’t any sitting in it. Any ideas where to start? I’ve since had the bowl back off the carb and it still looks good and clean. I’ve taken the fuel line off from the pump and it’s pushing fuel out albeit not a lot but it does still move fuel I think it might be getting a tad weak but I’m not convinced it’s my problem Share this post Link to post Share on other sites
953 nut 51,737 #2 Posted October 22, 2018 If you are using gas that has ethanol in it, STOP! You can locate ethanol free gas on this site. https://www.pure-gas.org/ When you cleaned the carburetor did you soak it in a quality carburetor cleaner and use compressed air to blow out all the tiny passages? 2 Share this post Link to post Share on other sites
Torrence20 19 #3 Posted October 22, 2018 Thanks for the gas advice but there is none near me and yes I soaked it in the best dip avalible to me ran it’s thru my ultrasonic sprayed out all passages with brake clean followed by air 1 Share this post Link to post Share on other sites
Torrence20 19 #4 Posted October 22, 2018 Any one aware of a flow rate these pumps should put out? ie. after x amount of revolutions of the engine there should be x amount of fuel in measuring cup? Share this post Link to post Share on other sites
Mows4three 825 #5 Posted October 22, 2018 Torrance20: Find a marina near you. They sell gasoline with out ethanol in it. I won't run anything but it in my 2-cycle equipment. We still run Ethan all laced fuel in the summer in our tractors but switch over to non-ethanol fuel in the fall so they over-winter without worries. Cheers! Dave 1 Share this post Link to post Share on other sites
The Tuul Crib 7,332 #6 Posted October 22, 2018 21 minutes ago, Mows4three said: Torrance20: Find a marina near you. They sell gasoline with out ethanol in it. I won't run anything but it in my 2-cycle equipment. We still run Ethan all laced fuel in the summer in our tractors but switch over to non-ethanol fuel in the fall so they over-winter without worries. Cheers! Dave Yeah Dave I agree with you ethanol free is the way to go. I run nothing but ethanol free and all my small engines. 1 Share this post Link to post Share on other sites
520hC-120 136 #7 Posted October 22, 2018 Sounds like a fuel pump to me. My 520h had this same problem not too long ago and I replaced the pump with an original. Now it works fine. Share this post Link to post Share on other sites
Torrence20 19 #8 Posted October 22, 2018 Any one had any luck with the aftermarket mechanical pumps? Found a couple of them for around 35 bucks Share this post Link to post Share on other sites
clueless 2,898 #9 Posted October 22, 2018 I've used a couple, they seem to work fine. Share this post Link to post Share on other sites
bitten 133 #10 Posted October 22, 2018 I would try Sea-foam first. 2 Share this post Link to post Share on other sites
peter lena 8,072 #11 Posted October 22, 2018 I agree with , bitten , sea foam gets it done. with the fuel we have today , any advanced help will take care of it. I initially used the sea foam aerosol , and the hot soak prescription , that really got things moving and probably loosened up a varnish build up. I regularly use sea foam and stabil for any longer term idle issues. don't wait for carburetor issues , stay after it , pete Share this post Link to post Share on other sites
elcamino/wheelhorse 9,054 #12 Posted October 22, 2018 6 hours ago, Torrence20 said: Any one had any luck with the aftermarket mechanical pumps? Found a couple of them for around 35 bucks You can get an electric pump (Facit Posi Flo #60300n ) from Aircraft Spruce for $39.46 . That includes shipping. 1 Share this post Link to post Share on other sites
Torrence20 19 #13 Posted October 22, 2018 (edited) I was at an update class recently and they advised to stop using sea foam and start using stabil marine 365. Test results showed sea foam to be hard on rubber components when used with fuel with ethanol in it... you can take that for what it’s worth. And I haven’t decided if it want to go thru the hassle of messing with putting an electric pump on or just go with another mechanical Edited October 22, 2018 by Torrence20 Typo Share this post Link to post Share on other sites
953 nut 51,737 #14 Posted October 23, 2018 (edited) It is the ethanol that is hard on rubber parts! Edited October 23, 2018 by 953 nut Share this post Link to post Share on other sites
Torrence20 19 #15 Posted October 23, 2018 I’ve always been a marvel mystery oil fan myself Share this post Link to post Share on other sites
BESTDOGEVER 218 #16 Posted October 28, 2018 I'm about 3 years into my aftermarket pump on my 310 still working great. The boggong on the hill is kind of a dead giveaway as a fuel problem the aftermarket pump was about 35 bucks Share this post Link to post Share on other sites