Snapper commercial series 18

[slomo]

Got a new to me used Snapper CP215518HV Commercial. Has a Honda GXV160 on it at 5.5hp.

Engine serial number GJAJA-1009562
Type A1AS

Here goes the story.

Engine had 149psi of compression and held for 10 min easy. Removed valve cover. Rockers were ultra sloppy. Got them set to 0.006" and 0.008" exhaust. Now it has 110psi and holds there. Engine smokes. Owner said it was way over filled with oil. And he removed oil to the full mark. Now engine didn't smoke. I picked it up in the dark, bad move on my part.

Anyway at home, oil was exactly on the full mark. Fired it up next day. She's a smoker. Changed oil and put it back exactly on full on flat ground. Noticed fresh oil was dripping on the deck under carb. I was like what?? Leaking from the air filter/carb 90 degree elbow onto the deck. Removed the block vent hose that runs to carb. Blew oil out of the dipstick with stick open. The vent hose is open but has restriction/baffling. Guess to slow down oil from escaping. Anyway engine running and vent hose off carb, you see oil vapor pushing out the hose constantly. Say 30 seconds later you see oil drips heading to the carb slash cylinder.

Also the revs were sky high when I got it. Kicking around 4500rpm LOL. Someone put a new OEM carb on it. Jets were shiny brass yellow, float was clean white plastic. Zero residue in bowl. I was stunned. Owner said it had a new carb. Was thinking Chinese in my head.... Fixed the throttle cable for proper revs, tach verified.

At 110psi on compression, I thought the rings were good. Guess the oil ring is not working. Getting blow-by into the cylinder from vent line. Was shocked to see basically 150psi. So is my diag correct? She needs new rings and maybe a piston? Definitely an oil control issue.

slomo

 

[bertsmobile1]

Could be a head gasket blown into the push rod tunnel / timing belt tunnel (can never remember which one is what )

 

[slomo]

Could be a head gasket blown into the push rod tunnel / timing belt tunnel (can never remember which one is what )

I had that on my mind too. But this is a Honda GXV160 commercial engine. Also the compression gauge held PSI as long as I didn't fiddle with the hose off the gauge. I've never heard of these engines tossing a head gasket. Course with super high revs when the previous owner started it, anything is fair game. No telling who installed the new carb to create the high revs. Think the last owner is a big trash picker upper and resells what he finds on peoples curbs. I would of thought the compression would of lowered some. Needle didn't budge at all in say 15 minutes.

So holding compression got me thinking bottom piston oil ring. Much easier to pull the head than open the case up I guess. This is a new purchase off of facebook marketplace. Previous owner agreed to refund my money next Sunday. Hmmmm. Wonder if I should pull the head off???



slomo

 

[slomo]

Look at the cylinder fire ring. Looks like a stout gasket.

So super high revs, way too much oil. Head gasket makes some sense.

There is hardly anything on Google about a GXV160 and blown head gaskets.

 

[slomo]

Removed the head. Head gasket was perfect. Like you removed it from the OEM Honda package. Same gasket as above. Zero blow out evidence. Onto the piston.

Noticed when the piston goes back up it pushes a small dribble of oil. Tells me the rings are seized or broken slash non functioning. Has good compression at 110psi. Cast iron bore was cherry. Oil ring must be dead. I'm calling it = piston rings and maybe a new piston. What do you guys think?

slomo

 

[bertsmobile1]

Other thing to check is the breather.
They do get stuck closed which will cause excessive crankcase pressure and lots of smoke .

 

[slomo]

Other thing to check is the breather.
They do get stuck closed which will cause excessive crankcase pressure and lots of smoke .

I did. It's open but has restriction blowing into it with your mouth. Thought it was baffling to slow any oil down from leaving the block. I figured it would be wide open slash essentially no restriction. Are they wide open?

Think I answered my own question. Most all breather hoses are slightly restricted or baffled to limit oil leaving the engine.

slomo

 

[bertsmobile1]

I did. It's open but has restriction blowing into it with your mouth. Thought it was baffling to slow any oil down from leaving the block. I figured it would be wide open slash essentially no restriction. Are they wide open?

slomo

Reed valve so you should be able to suck ( emptying the crankcase ) but not blow.