Honda GCV190 Leaking Exhaust Valve Stem

[volvofan94]

Hi All,

I'm trying to restore a Honda HRX217K5HZAA (the electric start model) I recently purchased used for a great price. However, is the engine is torn apart, in a tote, and previous owner said it smoked while running. "Some assembly required" is the theme for this project, but it's great to see how Honda designed these engines.

Got around to look at the cylinder side of the block, removed the intake and exhaust valve springs and to my surprise the exhaust valve oil seal is missing whereas the intake has one. I'm feeling confident this may have caused the smoke from the muffler reported by the previous owner. Also, the exhaust port on the head and piston top is covered in burnt oil. The spark plug was coated in oil too.

Do I look into replacing the exhaust valve guide? Or would purchasing a valve stem oil seal for the exhaust valve be a good way to go?


Thank you!

 

[StarTech]

Well it got to be either a HXA or HZAA but it can't be both.

First there is no exhaust valve stem seal. Second there is no valve guides available so if badly worn it is a new cylinder assy.

 

[volvofan94]

Sorry for the confusion on the model number, I corrected my mistake.

Tonight I'll do a leak down test on it to see if there's an issue with the cylinder block. If there is, then it's time for a replacement.

 

[volvofan94]

Quick update:

Did the leak down test during the week, and the engine passed. Also, I took the piston out, placed carb cleaner in top of the cylinder to check for leaks on the valves and cylinder head casting, no leaks were found. Lastly, I got ahold of an abbreviated shop manual for the GCV190 and checked the tolerances for the PTO, flywheel, and crank rod journals. Those are all within spec. Parts are on order then when they arrive, I will begin putting the engine together and start it up! Still at a loss why the PO said the engine smoked when it last ran...

My next question is, how much crank end float is normal on the flywheel side of a GCV190? Compared to other Honda lawn mower engines I've torn apart the GCV190 seems to have more end float.

 

[volvofan94]

To close out the thread, I got the engine running last week and ended up replacing the entire cylinder assembly as suggested, but went further to replace the piston and rings too. The crankshaft was within spec as was the connecting rod and wrist pin. Started the engine and no smoke!