GXV140 Overheating

This is still a problem. I've checked everything I can, cleaned everything I can. It appears to be running lean, causing overheating and also hunts. Carb is clean. I'm thinking air leak, maybe head gasket.

Any one have head gasket problems before? How easy of a replacement is this? Thanks

-There seems to be a bit of oil spray coming thru the breather, not much just a little.
-I ordered new carb gaskets just to be sure I didn't have a leak in one of them. They seemed to be stuck on pretty good and I doubt they were leaking, but hopefully that solves it.
-The RPMs are set at the manual recommended settings. I attempted to increase the RPMs at the governor which resulted in a runaway every time. I could not get the RPMs any higher than the recommended levels.
-Engine runs very smooth at low RPM. Idle screw works great.
-I seemed to notice more and more hunting going on when its warming up, maybe this is normal, not sure. No hunting when I engage the blade.
-Engine runs smooth (seems to me anyway) when I'm mowing, but still overheats. I had to let it cool between mowing the front and the back.
-Also ordered replacement governor springs, just because.
-Opened up valve cover, not much to see in there.
-Seemed to be air coming out between the head and the muffler? This seemed weird to me, probably not supposed to happen... Maybe I should investigate this further? I had the muffler off during this whole ordeal and everything seemed normal there. Maybe I put it back on wrong or air is coming around from somewhere else.

I ordered the shop manual off of Amazon, I hope it helps. I'm worried that I've fought for this mower and dumped money into it only for some probably easy issue to haunt me for the rest of my days. And I'll spend another $150 for the shop to mess with it in the off season, unless I can get it figured out. I should have taken my $500 and bought a new mower instead of a 14yr old one...

Could running 91 octane fuel be causing this?? A friend at work suggested that I step it back down to 87 octane.

KC_kid said:

Could running 91 octane fuel be causing this?? A friend at work suggested that I step it back down to 87 octane.

Click to expand...

Worth a try :/

Hey Dudes, I apologize for never finishing this thread. After re-reading the whole thing just now, how exhausting this problem was!
The solution for my problem - run 87 octane gas. Not 89 and not 91 and not 93 Octane and preferably with no Ethanol, lucky I could find a station close with no Ethanol (pure-gas.org).
Mower runs like a top now, start to finish. This should turn out to be a lifer, I don't plan on replacing my mower!

Wow thats wierd
I have run my GXV 140 and GXV 160 on Shell V Power Nitro + ( NB genuine 99 Octane in the UK ) for 7 years , no problems until. The current one of running rich on the GXV 160 ( but I think its down to a a very clean looking but 7 year old air filter. ) ordered a new air filter!

I have an HR215HXA that I purchased new in 1999. I have used premium unleaded gas. This spring the mower seemed to be overheating, throwing oil out of the crankcase breather. I found this post, changed to low octane unleaded gas. The mower has run fine since and no oil coming out of the breather. Thanks for the post.

If These 2 engines are allowed to run in a over heat condition for an extended period of time the real culprit will rear its ugly head and low octane non ethanol gas wasn't the solution. I suggest start setting any extra money aside in a mason jar labeled - new mower jar - because it's going to be needed.

I was just reading this thread and thought my experience 2 or 3 years ago might be helpful to someone:
My golfing buddy's 25-yr old Toro walk-behind mower started exhibiting the same symptoms as this thread's subject mower. I offered to help, and after using it a few times until it died out, and noticing that I had to add fuel before each use (after a one week interval between uses) I concluded that fuel was leaking through the carburetor (while the mower sat in my garage waiting for its next use) and into the engine, thus thinning out the oil and causing poor lubrication while the engine was running until it overheated causing the engine to stop. I figured it was a bad float valve in the carburetor, but rather than mess with the carburetor, I obtained a cheap shutoff valve and spliced it into the fuel line (the mower did not previously have a shutoff valve) and instructed my buddy to close the valve immediately after each mowing, and the mower never had another problem.

Maybe the blade is dull. This will cause the engine to overheat.