Mower valve lapping

[Gary Olson]

The Bad Boy mower manual says the Kawasaki engine needs a lap the valve seats, clean the combustion chamber, and lap the valve clearance soonly. I haven't lapped a valve or seen a combustion chamber in a few decades; and it was a V6 Mustang. Anything twiggly I need to know?

 

[lugbolt]

not needed.

 

[jaxs]

No offense intended, but terminology used in your post makes me believe you are misunderstanding what the manual said.

 

[Gary Olson]

No offense intended, but terminology used in your post makes me believe you are misunderstanding what the manual said.

Nope, found the service manual. Specifically shows getting a special tool for lapping the valve seats; and cleaning the valve mating surfaces for the seats.
The owners manual stated to set the valve gap, and lap the top of the valve stems but the service manual said only gap the valves properly.

 

[Runs With Scissors]

I don't have any insight on this, but WOW.

At least they are honest about it I guess.

Speaking of valves though.

In my "more stupid days" I bought a used Honda CRF 450F and somewhere about 30 ish hours after I had it, I stalled it in the woods, and had to tow/push it out cause the valves "stretched".

I fixed it, and then promptly sold it, just to buy a "new" Honda CRF450F..........Well guess what.......about 30'ish hours after I had it, those damn valves stretched again and I was pushing/towing it out....again.

One of the guys I rode with kept giving me sh!t about buying a Honda.

Long story short, I called Honda, and there answer was the valves stretch was because, and I quote, "It is a high performance racing bike". He must have repeated that 20 -30 times during our conversation.

Disgusted, I hung up, ordered new valves, fixed it and promptly sold it.

Then I went out and got me a "brand spanking new YZ450F", and never had another problem...........(except for crashing......crashing was always a problem.....My mind would constantly "write checks, that my body could not cash')

So now I ride a L2501

 

[William1]

Before I did anything, I'd do a leak down test to determine if anything needs to be done.

If something needs to be done to the valves....
You remove a valve
Inspect the valve seating area and seat, looking for pits. Pits? New valve, cut the seat.
Cupped valve? Replace the valve, may have to cut the seat, might be able to lap.
Light wear? Lap the valve
If... after the work is done and you have too tight valves, you lap the stem to shorten it enough to enable proper adjustment.
If you do not understand any of this, you need a QULAIFIED mechanic.

Honda MX bikes had a too soft valve material, the valve faces cupped and needed replacement, the fix being aftermarket stainless steel valves. Owners could get away with shimming once and if they kept reshimming, eventually catastrophic failure was the result.

 

[Runs With Scissors]

Owners could get away with shimming once and if they kept reshimming, eventually catastrophic failure was the result. should Should just buy a Yamaha and be done with it.

Fixed it for ya!

 

[mikester]

Fixed it for ya!

I think I'd rather get a Kubota diesel and not worry about it!