Stepney 2,311 #1 Posted June 15, 2017 Hey, all. Took the old 1077 out for a brief run this afternoon, just wanted to cut a few short passes.. could have used the push mower but figured the old Horse would like the exercise. Fired right off as it always does, ran perfectly. Warmed it up, and mowed down the section of grass, as I slowed the engine and had disengaged the deck, it suddenly made a pop and started making a funny noise through the exhaust, just like the sound of the decompresser when the engine first starts.. only it persists now through the entire throttle range, and it is backfiring pretty bad. I tried to idle it to the shed but it didn't have the power to move, so I pushed it down. Any idea what's going on here? I just had it apart a few weeks ago to check the valve lash, as per the book, and everything was pretty much spot on, but I set it anyway. What would make it do this?? Share this post Link to post Share on other sites
tunahead72 2,329 #2 Posted June 15, 2017 37 minutes ago, Stepney said: ... I just had it apart a few weeks ago to check the valve lash, as per the book, and everything was pretty much spot on, but I set it anyway. What would make it do this?? No idea, but I would check your recent work carefully, just to make sure you put everything back together properly. I'm sure others will have better ideas. 1 Share this post Link to post Share on other sites
R. L. Addison 299 #3 Posted June 15, 2017 Sounds to me like an exhaust valve problem to me, - carbon, broken spring, crack in valve or seat (rare), valve rotator (again rare ), or not impossibly, compression release. Where there are moving parts, things can go amiss! Share this post Link to post Share on other sites
Stepney 2,311 #4 Posted June 15, 2017 Yeah, I figure it was the valve. I'll start pulling it apart later on tonight.. hope it isn't anything too serious it was running perfectly 5 minutes earlier. Share this post Link to post Share on other sites
skippy1969 135 #5 Posted June 15, 2017 I agree,I would check the valves. Share this post Link to post Share on other sites
Stepney 2,311 #6 Posted June 18, 2017 Well, I went to work on it today and I had to move it out of the way so I could roll my old Broadmoor out, .. and wouldn't it fire right up and run perfectly. I checked everything over anyway, and found nothing wrong. ..I have no idea now. Share this post Link to post Share on other sites
953 nut 50,997 #7 Posted June 18, 2017 6 hours ago, Stepney said: fire right up and run perfectly. I think it had a chunk of carbon keeping the valve from closing all the way and it passed it, sort of like a kidney stone. 2 Share this post Link to post Share on other sites