Oldtoolsnewproblems
ArboristSite Operative
So my 80s era Ariens rideon has a Kohler K3610s 18 hp engine in it. The K3610 i believe is a higher compression version of the K341, making 18 instead of 16 hp but running a much hotter exhaust and larger carb. I've been running it the last year ish with a spare carb from a K341 becasue I lost a piece of the original carb during cleaning. the smaller carb worked ok, great idle and great high end, but always hunts in the mid RPMs (i didn't want to tweak the governer) and the biggest issue was the huge backfire i would get EVERY time i shut it down, bad enough even I couldn't live with it. I finally found the missing carb part and now my issues begin.
The K3610 carb has a shut-off solenoid to stop the backfire and dieseling, I've never seen a replacement carb that still has that. I put the original carb back in, set the float and tuned it. it idles great and revs up way smoother than the little carb did, but as soon as it hits the high range, it starts spitting black smoke, running pig rich. I had replaced the float seat so i suspected that, but hooking up a fuel line to it, pouring gas in until the bowl was full and then putting my mighty vac on it it held 5-10 psi with only a slow leak down. unless that is supposed to be a perfect seal, which seems unlikely, I don't think it's the seat. what else could I be missing? I can't imagine its too much fuel pressure, as the other carb did not have this issue. i have hte main screw turned basicly fully in, theres nothing I can do with the screws to get this into spec. I can see a clogged passage making it run lean, but pig rich?
unless anyone has a magic 8 ball I fear I'm just gonna take it apart and together again and hope for a change.
The K3610 carb has a shut-off solenoid to stop the backfire and dieseling, I've never seen a replacement carb that still has that. I put the original carb back in, set the float and tuned it. it idles great and revs up way smoother than the little carb did, but as soon as it hits the high range, it starts spitting black smoke, running pig rich. I had replaced the float seat so i suspected that, but hooking up a fuel line to it, pouring gas in until the bowl was full and then putting my mighty vac on it it held 5-10 psi with only a slow leak down. unless that is supposed to be a perfect seal, which seems unlikely, I don't think it's the seat. what else could I be missing? I can't imagine its too much fuel pressure, as the other carb did not have this issue. i have hte main screw turned basicly fully in, theres nothing I can do with the screws to get this into spec. I can see a clogged passage making it run lean, but pig rich?
unless anyone has a magic 8 ball I fear I'm just gonna take it apart and together again and hope for a change.