johnnymag3 2,515 #1 Posted June 21, 2020 (edited) Have an M10 with low hours......346 to be exact. Starts immediately, runs perfect for a few minutes... runs at wide open forever....but when its at low rpm's after 2-3 min. all H3LL breaks loose... snort, pop, powie...stalls. Wait 5 min, starts right up and then the same cycle begins again Thought there was trouble with fuel so I removed tank, lines , filters carb. Cleaned and replaced everything. SAME situation. Put on a tested carb from an M12...and did same thing. Snap .crackle . pop. Like a shotgun !!! Tried a freshly rebuilt carb,,,,,,,same issue. Changed plug, no change....There is no fuel in the filter after a bit, and its usually dry looking. If I mess with the choke flap it will be better when it sucks in some fuel. This seems like maybe the fuel pump is my only link left to change in this saga. Please advise..... Also ran it with no gas cap, no change... BAFFLED IN NY THANK YOU AS ALWAYS Edited June 21, 2020 by johnnymag3 addition Share this post Link to post Share on other sites
squonk 41,023 #2 Posted June 21, 2020 Take the fuel filter off. I had some of those clear plastic ones air lock and cause issues. Share this post Link to post Share on other sites
johnnymag3 2,515 #3 Posted June 21, 2020 5 minutes ago, squonk said: Take the fuel filter off. I had some of those clear plastic ones air lock and cause issues. going to do that right now......will let ya know the outcome.... I will be under here while its running.... Share this post Link to post Share on other sites
johnnymag3 2,515 #4 Posted June 21, 2020 (edited) took off filter, same issues.....exactly...... thats me wanting to scream bloody help Edited June 21, 2020 by johnnymag3 addition Share this post Link to post Share on other sites
Tractorhead 9,064 #5 Posted June 21, 2020 Did you cleanup the fins with removed cover? maybe engine overheats while airpath is clogged? 1 Share this post Link to post Share on other sites
johnnymag3 2,515 #6 Posted June 21, 2020 2 minutes ago, Tractorhead said: Did you cleanup the fins with removed cover? maybe engine overheats while airpath is clogged? does this after 2-3 min. also the only thing on this tractor is wax.. !!! He does not mow with it. Machine plows snow only, and does that very little Share this post Link to post Share on other sites
Tractorhead 9,064 #7 Posted June 21, 2020 Can you make a small vid of that, that can be helpful to hear that Sound before stalling. Share this post Link to post Share on other sites
johnnymag3 2,515 #8 Posted June 21, 2020 Could it be electrical? Points? any ideas will help....im running out of places to look. 1 minute ago, Tractorhead said: Can you make a small vid of that, that can be helpful to hear that Sound before stalling. it pops, spits and misfires....I have no way to video, sorry Share this post Link to post Share on other sites
Tractorhead 9,064 #9 Posted June 21, 2020 If you have a Boat tank or a Fuelcanister, put it on the Hood, connect a line to the carb and try it without the Fuelpump. Share this post Link to post Share on other sites
johnnymag3 2,515 #10 Posted June 21, 2020 12 minutes ago, Tractorhead said: If you have a Boat tank or a Fuelcanister, put it on the Hood, connect a line to the carb and try it without the Fuelpump. ok, not through the pump then, just gravity feed to carb. like the old models 1 Share this post Link to post Share on other sites
Tractorhead 9,064 #11 Posted June 21, 2020 Just to ask, the oillevel is ok? Share this post Link to post Share on other sites
johnnymag3 2,515 #12 Posted June 21, 2020 6 minutes ago, Tractorhead said: Just to ask, the oillevel is ok? Full, and clean Share this post Link to post Share on other sites
ebinmaine 67,274 #13 Posted June 21, 2020 No points so that's out. Engine carboned up inside? 2 Share this post Link to post Share on other sites
Tractorhead 9,064 #14 Posted June 21, 2020 Ok, just asked to be sure. Share this post Link to post Share on other sites
johnnymag3 2,515 #15 Posted June 21, 2020 2 minutes ago, ebinmaine said: No points so that's out. Engine carboned up inside? I had this engine apart last year to look it over, cuz he wanted me to. but it was spotless 1 Share this post Link to post Share on other sites
Skipper 1,788 #16 Posted June 21, 2020 (edited) Perhaps a coil gone bad. Acting up when heated. Haven't seen it but.......... Like Eriks input on carbon build up too! Edited June 21, 2020 by Skipper 5 Share this post Link to post Share on other sites
johnnymag3 2,515 #17 Posted June 21, 2020 11 minutes ago, Skipper said: Perhaps a coil gone bad. Acting up when heated. Haven't seen it but.......... this engine does not have a coil....its a magnum 10 hp....this happens after like 2-3 minutes. If you yank the throttle to full in time, it will stumble, then run fine at full throttle all day....its when you are at half or lower on the throttle. Lower rpms So strange Share this post Link to post Share on other sites
ZXT 2,401 #18 Posted June 21, 2020 28 minutes ago, johnnymag3 said: this engine does not have a coil.... Yes it does, bolted under the shroud. It's not an automotive style coil, but it's still a coil. Coil breaking down is my first guess, but I think @Tractorhead is on to something. Sounds like it is getting hot and dying out. It may not mow grass, but a rodent could certainly pack the cooling fins full of debris! 1 Share this post Link to post Share on other sites
johnnymag3 2,515 #19 Posted June 21, 2020 If you saw where this machine was kept, there are no mice !!! he is so meticulous. Anyways, Ive been through it many times and there are no foreign objects anywhere. It happens way before it even gets hot....sometimes not at all. It will run full all day long, but when its at a lower rpm its acts up....Badly... Share this post Link to post Share on other sites
johnnymag3 2,515 #20 Posted June 21, 2020 There is nothing in that area of cooling...ive checked... ..im going to try the isolated gas tank idea, and take the fuel pump out of the equation Share this post Link to post Share on other sites
johnnymag3 2,515 #21 Posted June 21, 2020 if it was the coil, do you think it would be ok sometimes....then fail others ? It will run at full tilt all day.....Very strange situation....but I do appreciate all of the input....hope to find the problem soon !!!! Share this post Link to post Share on other sites
8ntruck 6,991 #22 Posted June 21, 2020 I think the gravity fed fuel experiment will be very informative. 1 1 Share this post Link to post Share on other sites
johnnymag3 2,515 #23 Posted June 21, 2020 (edited) 17 minutes ago, 8ntruck said: I think the gravity fed fuel experiment will be very informative. I do also...it removes fuel feed from the problem....This is the tractor last year, before restoration Edited June 21, 2020 by johnnymag3 wont show picture 1 Share this post Link to post Share on other sites
skrusins 128 #24 Posted June 22, 2020 If your sure its not a fuel problem then it's electrical maybe the mag needs to be check for clearance or a carbon buildup under the head and make sure the valve seats are good and not sticking. If all else fails try an electric fuel pump just for a test. You can put in place of the fuel filter just for the test. 1 1 Share this post Link to post Share on other sites
tunahead72 2,403 #25 Posted June 22, 2020 1 hour ago, johnnymag3 said: ...This is the tractor last year, before restoration I'm being thrown off by this photo... The vertical muffler tells me the engine is a K series, but it does look like a Magnum peeking out behind it. Don't know if it matters, but has the exhaust been modified at all? Share this post Link to post Share on other sites
