When to check motor valve clearance.

H

Hunkydory

New member
Lots of contradictory opinions on how often to check motor valve clearances here & on the internet. From experience with my old Honda 40’s & lots of recent reading about it, I decided it was time or perhaps even past time to do it now at 540 hours on the replacement Honda 60’s. I found one valve out of tolerance on the #1 motor & 5 out on the #2 with some out enough on the #2 motor to be somewhat worrisome, because I don’t know & through research reading, find any direct point, where the out of spec, could start creating engine damage. Fortunately, the valves on both motors were not very far out of tolerance, so doubt any damage was done & now very glad, I decided to check & adjust before motor damage did occur.

I will be checking mine at about every 400 hours in the future, though I know one person who has three thousand hours on their motor & it’s still running great without ever having the valves checked.

Jay
 
Hunkydory":1pwofblp said:
Lots of contradictory opinions on how often to check motor valve clearances here & on the internet. From experience with my old Honda 40’s & lots of recent reading about it, I decided it was time or perhaps even past time to do it now at 540 hours on the replacement Honda 60’s. I found one valve out of tolerance on the #1 motor & 5 out on the #2 with some out enough on the #2 motor to be somewhat worrisome, because I don’t know & through research reading, find any direct point, where the out of spec, could start creating engine damage. Fortunately, the valves on both motors were not very far out of tolerance, so doubt any damage was done & now very glad, I decided to check & adjust before motor damage did occur.

I will be checking mine at about every 400 hours in the future, though I know one person who has three thousand hours on their motor & it’s still running great without ever having the valves checked.

Jay
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The mfg. service manual tells when scheduled maint. should be performed.
Too tight doesn't allow the valve face to rest on the seat long enough for cooling, resulting in Burnt valves. too loose makes excessive noise, WAY too loose can spit out the shim.
:thup :thup :wink: Three thousand hrs. is a lucky person living right. :)
 
Some of that was probably how good of a job they did at the factory. I suspect next time they will be pretty close to where you set them.
 
Jody, very likely they will. From our conversations, it did with you in the past & me too on my old Honda 40’s.

The service manual, as tsturm points out does recommend a much more often approach, such as accessing to check valves, water pump, thermostat, spark plugs & timing belt every year, which I doubt many do or for that matter necessary to do. The same with daily run checks. There is a more moderate approach, that most of us follow, especially those who chose to do their own maintenance, where we try to balance the cost & time taken for preventive maintenance with the actual need for it. The valve check & adjustments are, I think a good case in point. If I owned & operated a single engine aircraft instead of slightly overpower twins on a boat, the preventive maintenance would align strictly with the manufacturer recommendations enhanced by law regulations.
 
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