honda mower issues

[honda 03]

the rpms go up then back down a few times then straightens out. then does it again. otherwise runs well. it only seems to do it when the blades are engaged. I also hear a screeching sound when I'm cutting tall grass. what could be the cause of these things. the carb is brand new. also, it was surging before i put the new carb on.
model number- 917.377792
serial number- 040503m 002201
the rear wheels also lockup when pulling backwards

 

[Oddjob]

The rpm’s are due to the governor adjusting to the load you are putting on the engine. I wouldn’t worry about it. The locked up wheels are due to the pawl in the driven axle being stuck, probably needs lubrication. Very common on Hondas. You need to take rear wheels off and disassemble the gear assembly. You’ll need circlip pliers to get it apart. Carefully note the order that the parts come out in, so you can reassemble. The pawl sits on a tiny spring that resides in a groove in the axle. The pawl looks like a small elongated letter D. Clean and grease all parts and reassemble. Do one side at a time so you have a model to go by when you screw up the order of the parts. But don’t worry, there are diagrams on line showing all this. You can try to squirt penetrating oil past the gear etc without disassembly, but that likely won’t work. While you have the axle exposed, make sure there isn’t corrosion where it goes through the body of the mower. I have had a Honda where this was the reason it was so hard to reverse but usually it’s the pawl. The pawl is supposed to engage when you engage the drive and then retreat into the groove (the gear has a ramp on it that pushes the pawl down) when you pull back.

 

[Oddjob]

Re screeching noise: suspect you have a slipping belt. When the tall grass puts an extra load on the blade the belt powering the selfpropel slips. Try tightening the belt. If the belt is old or glazed, you may need to replace it.

 

[nbpt100]

I may be wrong but I do not think the mower you have has an adjustment on the belt. You can try straying some belt conditioner on it to see if that noise goes away. It is not a permanent solution. It is more to help trouble shoot. If the noise goes away you know pretty darn sure it is the belt. You may want to replace it at some point but it does not sound like an urgent problem.

It is possible the noise could be the blade clutch. Hard to say with out being there to see and hear.

Also try to adjust the governor to make sure it is set correctly. Plenty of on line videos and it is easy to do. It is possible it has moved a hair and is causing some of the surging issues.

Good advice above on servicing the rear wheel drive issues. Think of the mechanism as like a ratchet. It is called a one way clutch. It only drives in one direction. Like a ratchet. Clean it out good. Use steel wool to remove any rusting on the shafts. Use a light grease or oil. Keep in mind the grease will attract grit to collect. There are seals but they are not perfect and likely worn on any machine with decent use. You can also put some light motor oil in the ball bearings while you are at it.

All sound like minor problems but jump on them before they are worse. Good luck!

 

[honda 03]

sounds relatively easy. do you guys have access to the books on this mower?

 

[nbpt100]

Plenty of good videos to guide you on You Tube.

 

[Oddjob]

When I suggested tightening the belt, I was using shorthand. I really meant to tighten the cable for the self-propel. This would in turn pull harder on the belt when you pull the bale back and act to tighten the belt. The cable could have stretched a little or maybe slipped. Or the belt may have stretched or gotten glazed/less flexible. Or all of the above. Tightening the cable is the easiest fix, so I would try that first. But do it a little at a time like one revolution of the nut, and then see if the squeal went away. Look in your owners manual for the procedure for cable adjusting and for belt replacement. The Honda manuals are all available online. I’ve never had noise coming from the blade clutch, but sounds like nbpt100 has. As he said, it is impossible to nail these things perfectly without actually having the machine in front of you. I could be completely wrong, but this is where I would start. Good luck.