RPM Update
A couple of weeks ago I put the mower on the bench and went to work.
First, removed and cleaned the carb. I discovered that the previous runaway was caused by not firmly seating the carb against the cylinder head, there is 1/32 or so of unthreaded stud that prevented snugging it up. I didn't see that at first so I didn't use the spacers from the air cleaner housing. The local Honda dealer didn't have a carb kit so I didn't replace all of the gaskets/o rings but I did replace the larger spacer-gaskets which would be 13, 14 and 15.
After cleaning and re-installing I could not get RPM to 3200 on high. There are 4 points to adjust RPM (excluding governor): 1st is the throttle stop screw on the carb; 2nd is the adjustment screw on the control; 3rd is the ferrule placement of the throttle cable to the control and 4th is the throttle cable adjustment at the throttle lever. After tweaking and re-tweaking these adjustments I then proceeded to the governor with no affect on increasing RPM. Moving the governor arm manually would increase RPM so I started to tighten the governor spring by bending the attachment "hook" to shorten it. Still, 3000 rpm was all I could get.
When I put everything back together to cut the lawn as soon as I engaged the blade the RPM's shot up 3600 before I switched to low speed and cut the lawn at 3000 rpm. About half way into the cut the engine began stalling out when I tried to re-engage the blade after emptying the bag. I never did try to engage the blade to check RPM when the mower was on the bench.
1. I'm getting inconsistent RPM readings from the tach (
Digital Hour Meter Tachometer Tach Tacho for Yamaha KTM Honda Kawasaki BMW Motorcycle Dirt Bike ATV UTV Quad Generator MX Snowmobile Boat Outboard Jet Ski 4 2 Stroke Gas Engine : Amazon.com : Automotive ) most of the time it is appears to be accurate, but at others I can hear the engine rev up yet the tach displays 2500 rpm.
Anyone have recommendations for a decent tach? The non-contact versions won't allow me to install and keep it on the mower so I can monitor performance. I would like one to keep on the mower until I'm confident the issues are resolved.
2. Prior to cleaning the carb the RPM's would decrease when I engage the blade, now the RPM's increase. Which is right?
3. Why and when would someone replace the carb? I cleaned it according the video from the European site, there doesn't' appear to be any blockages. BUT, I didn't replace the o-ring on the "jet set, pilot" but it appeared fine. Also, I've heard about removing the choke butterfly to get at some balls??
4. When I adjusted the pilot screw it had no effect on rpm whatsover. Should that be???
The valves are dead on. Gas tank was cleaned and gas flows freely to carb.
I would appreciate and suggestions.
Thanks, Bob