garjess 0 #1 Posted June 29, 2016 I got a b48m motor from a friends grandpas barn. I've replaced all the ignition parts, cleaned and rebuilt the carb and fuel pump, checked intake for leaks, compression check 120-125 psi but I can only get it to turn 2900 rpm. It runs great up to 2900 but any faster and it spits and sputters, regardless of the carb settings. The only way it will go faster than 2900 is if I unhook the governor arm and manually move the throttle. Doing this, I can get it to about 3000 but it sounds awful. The name plate on the breather says 18hp at 3600 rpm When I got it, the intake wasn't attached to the motor and I later found out there were several Onans laying around. I'm wondering now if this is the correct carb for this motor. Plate on the motor B48M-GA 018/3417A A783309136 Plate on carb DD-11 Date 73 Any help with this would be appreciated. I'm out of ideas at this point. Thanks Gary Share this post Link to post Share on other sites
Maxwell-8 4,367 #2 Posted May 15, 2021 Maybe to late to help you but may help others: check is she is running on all 2 cylinders. Check if both exhausts are getting hot. Share this post Link to post Share on other sites
