All,
I am stumped by an issue I am seeing, and I am hoping someone in this forum can give me pointers of things to investigate.
I've a Honda Harmony II, HRR216S3DA from 1999. It has been a great mower, but the transmission recently gave up the ghost while self propelling up a fairly steep hill. While trying to engage the transmission, it was slipping and catching, and making a ratcheting noise. It also appeared to be making a knocking noise while it was disengaged also (note this, I will come back to it), when the engine was idled down low (couldn't hear any noise at operating engine speed). I knew the transmission was shot, so I rotated the belt off the transmission pulley, and out of the mower, and restarted the engine. Perfect engine noise, quite idle and revved up normally also (so, engine under no load to drive transmission pulley). In looking at the transmission, the engagement pawl lever and actuator were very worn, and oil had been leaking from the transmission. So, I ended up getting a new transmission kit, the cable holding bracket and rubber bumper (which bolts atop the transmission and under the driven pulley), and left and right side height adjustment arms (which slide over the transmission output shafts to the wheels). In this way, with the exception of the belt (which is pretty new) and the driven pulley (looks like new), everything else is new out to the pinion gears and wheels. Replacement was pretty straightforward, and everything went together very well.
Filled it back up with oil and gasoline, and the transmission works great! But ...
The mower has the same low speed knock it had before. Knowing it cannot be the transmission, it sure sounds just like connecting rod knock. After spending $200 to replace the transmission, I was sick to my stomach. I used the trusted big-screwdriver-to-ear method to "stethoscope", and things sounded normal under valve cover. If I listen to crankcase upper half (by the governor shaft), I can clearly hear a knock ... but, I am not convinced it is rod noise. The oil looks fine (but, it had only been in the crankcase for 10 min or so). I looked real close, and cannot see any metal flakes whatsoever. I replaced the blades (got new ones in order also) to no avail. Same noise. I guess I can mow the lawn, and see if it throws a rod, but if it is something less serious that I can fix, I'd rather do this before things get worse. Problem is, I cannot even conceive what else it could be.
Any ideas? Noise is proportional to RPM. Much more pronounced at lower RPM (but, there is less overall engine noise, so it is easier to hear). Still, as operating speed is increased, the noise diminishes until - at operating speed - all seems normal. Blades do not seem to be interfering anywhere. I am stumped at what to look at next.
Thanks in advance for your ideas!
Chris
I am stumped by an issue I am seeing, and I am hoping someone in this forum can give me pointers of things to investigate.
I've a Honda Harmony II, HRR216S3DA from 1999. It has been a great mower, but the transmission recently gave up the ghost while self propelling up a fairly steep hill. While trying to engage the transmission, it was slipping and catching, and making a ratcheting noise. It also appeared to be making a knocking noise while it was disengaged also (note this, I will come back to it), when the engine was idled down low (couldn't hear any noise at operating engine speed). I knew the transmission was shot, so I rotated the belt off the transmission pulley, and out of the mower, and restarted the engine. Perfect engine noise, quite idle and revved up normally also (so, engine under no load to drive transmission pulley). In looking at the transmission, the engagement pawl lever and actuator were very worn, and oil had been leaking from the transmission. So, I ended up getting a new transmission kit, the cable holding bracket and rubber bumper (which bolts atop the transmission and under the driven pulley), and left and right side height adjustment arms (which slide over the transmission output shafts to the wheels). In this way, with the exception of the belt (which is pretty new) and the driven pulley (looks like new), everything else is new out to the pinion gears and wheels. Replacement was pretty straightforward, and everything went together very well.
Filled it back up with oil and gasoline, and the transmission works great! But ...
The mower has the same low speed knock it had before. Knowing it cannot be the transmission, it sure sounds just like connecting rod knock. After spending $200 to replace the transmission, I was sick to my stomach. I used the trusted big-screwdriver-to-ear method to "stethoscope", and things sounded normal under valve cover. If I listen to crankcase upper half (by the governor shaft), I can clearly hear a knock ... but, I am not convinced it is rod noise. The oil looks fine (but, it had only been in the crankcase for 10 min or so). I looked real close, and cannot see any metal flakes whatsoever. I replaced the blades (got new ones in order also) to no avail. Same noise. I guess I can mow the lawn, and see if it throws a rod, but if it is something less serious that I can fix, I'd rather do this before things get worse. Problem is, I cannot even conceive what else it could be.
Any ideas? Noise is proportional to RPM. Much more pronounced at lower RPM (but, there is less overall engine noise, so it is easier to hear). Still, as operating speed is increased, the noise diminishes until - at operating speed - all seems normal. Blades do not seem to be interfering anywhere. I am stumped at what to look at next.
Thanks in advance for your ideas!
Chris