Temperature of cylinders on a 416h after mowing

[artfull dodger 329]

I would also take readings while she is running,  All engines will "heat flash" after being shut down, even liquid cooled ones.  The temps while running are more important that the heat flash temp right after shutting off the cooling flow of air guys.  

[Cee245 754]

 

@artfull dodger,

Great points about cleaning the carbon out and setting the valve gaps.

I haven't done this ever and have 800 hrs.  I would like to do this but I would need some guidance.  I've always been into Honda 250r' s which are 2 stroke and don't have a lot of experience dealing with a 4 stroke motor with the valves and such. 

Thanks Cory

 

[artfull dodger 329]

Its done with a cold engine and does take some engine tear down.  Both the exhaust manifolds/muffler and intake running with carb must be removed to access the lifter chambers.  You manualy roll the engine to TDC and then take your feeler gauge and check the clearance on both intake and exhaust valves.  It takes 2 wrenches to adjust the lifter.  One is a 9/16th and has to be really thin.  Onan used to offer a special wrench set for this.  Easier to get a cheap 9/16th wrench and grind it thinner to do the job.  After you do the first side, repeat the process for the other.  easy peasy.   Decabon is just removing the cylinder heads, cleaning them and the tops of both pistons, inspect the bore for any damage or odd wear, then reinstall new head gaskets and torque to sequence.      Mike

[Cee245 754]

Mike,

Thanks for the great info!

 

 I have done many repairs to my 416 but never have gone too deep other than ignition module under flywheel and I know mostly how to do this but don't want to hurt the aluminum(?)  heads. Would a wire cup brush in my 4 1/2" grinder clean and NOT DAMAGE the heads/ top of pistons ect?

 

I looked up a guy called Craig Arndt on YouTube. He shows in great detail how to do the valve adjustment on a 520. Seems like he does good work.

 

Are the P216 and P220 valve adjustment specs the same?

 

Very doable for me. Just need the precious time to do it.

 

Cory

[artfull dodger 329]

You dont want to use anything that will scratch the surface where the gasket goes and any scratches on the head help carbon stick more.  I use a brass wire wheel on my dremel motor tool to clean the non gasket areas, and a straight razor to make sure the gasket surface is scraped clean.  Then a trip in the parts washing tank to remove grime and any grit, then wipe down with clean shop rag and its assembly time.   A small putty knife works as well for scraping the carbon deposts off the non gasket areas and the to of the piston.  A rag and carb cleaner helps as well.  Just get the worst off, doesnt need to look factory fresh here.  You should be able to look up the valve adjustments online.  I would have to find my books to see if they are the same.   Google is your friend here.