BradButlerNC
Forum Newbie
- Joined
- Oct 3, 2011
- Threads
- 1
- Messages
- 3
Let me start this off by saying im new here. I work on small engines all the time, though i cant just figure this one out I figure theres probably guys here alot more experienced than me, have a shot at it - i tried to be pretty detailed. :smile:
Been messing with a riding mower my grandmother gave me, its like new but it quit on her and she went and bought another one. Has a briggs 14.5 OHV on it. Originally had the ****ty "nikki" carburetor, i tossed that in favor of a walbro (completely rebuilt) from another running 14.5 that had a knock.
When i got it i found the intake valve not opening was causing no start. No biggie, popped the valve cover, had a broken pushrod. Replaced pushrod, set both valves to .006 gap COLD.
Popped the flywheel cover off and pulled flywheel, key was fine but i replaced it anyway, sanded rust off flywheel and coil, coil gap is fine. New plug, strong blue spark when cranking. Also has fresh oil change of briggs SAE 30 oil.
Go to fire it up, it will turn and turn and not sound like its hitting at all, then itll POP and smoke back through the intake every 5-10 seconds or so while cranking over. This is with choke on, with choke off it just fires over and doesnt change a tone.
Heres whats NOT wrong with it that ive figured out.
Cam is timed correctly (verified correct piston location and valve timing with dial indicator)
Spark is timed correctly
Getting fuel, float not leaking, jetted correctly
Choke linkage and throttle linkage working correctly
All sensors working properly
Motor has plenty of compression, only about 10 hrs on whole mower.
What can it be? Only thing im thinking is there may be something with the valve lash. I may try opening it up to .008 and see if that helps. Ideas? I normally dont have this much trouble, but this damn thing is killing me.
Been messing with a riding mower my grandmother gave me, its like new but it quit on her and she went and bought another one. Has a briggs 14.5 OHV on it. Originally had the ****ty "nikki" carburetor, i tossed that in favor of a walbro (completely rebuilt) from another running 14.5 that had a knock.
When i got it i found the intake valve not opening was causing no start. No biggie, popped the valve cover, had a broken pushrod. Replaced pushrod, set both valves to .006 gap COLD.
Popped the flywheel cover off and pulled flywheel, key was fine but i replaced it anyway, sanded rust off flywheel and coil, coil gap is fine. New plug, strong blue spark when cranking. Also has fresh oil change of briggs SAE 30 oil.
Go to fire it up, it will turn and turn and not sound like its hitting at all, then itll POP and smoke back through the intake every 5-10 seconds or so while cranking over. This is with choke on, with choke off it just fires over and doesnt change a tone.
Heres whats NOT wrong with it that ive figured out.
Cam is timed correctly (verified correct piston location and valve timing with dial indicator)
Spark is timed correctly
Getting fuel, float not leaking, jetted correctly
Choke linkage and throttle linkage working correctly
All sensors working properly
Motor has plenty of compression, only about 10 hrs on whole mower.
What can it be? Only thing im thinking is there may be something with the valve lash. I may try opening it up to .008 and see if that helps. Ideas? I normally dont have this much trouble, but this damn thing is killing me.