GXV140 Overheating

[KC_kid]

Mouse nest blocking air flow.

I'm wondering if I find this under the cover somewhere. Looks clean at a glance, but I haven't removed cover yet.

 

[KC_kid]

No, I have not. I will make sure and do that when I'm working on it. Clean muffler, replace electrical, double check clean cooling fins, check RPMs and throttle linkage. Might get a new air filter although I hate to replace a filter I am 90% sure is clean. I know carb, oil and gas are clean. Engine acted exact same with 2 separate clean carbs and fresh oil. Running 89 octane gas.

I took off the muffler but there wasn't much to it, no apparent blockage and no spark arrester to clean. I replaced ignition coil and spark plug, although spark plug looked OK and I did not get the coil tested. Cooling fins were as clean as can be. Throttle linkage worked exactly as described in the manual. I also replaced the air filter with new. I had been using a Kohler air filter from HD and while it fit perfect, maybe it had too much restriction? I replaced with a Cub Cadet filter that had the Honda part number listed as a direct replacement.

The last thing I need to do is double check my RPMs are good, then I will mow mid week and hope it goes well.

 

[KC_kid]

The tach didn't come in yet but it was time to mow. I adjusted throttle and governor setting a tiny bit faster and mowed. Ran good and did the whole yard, never shut it off but when I was done, smoke puffed from the engine - not the muffler. Pulled dipstick and rotated the crank - smoke comes with each stroke, dipstick and muffler. It was overheating but not enough to shut it down.

What next? Could my rpms really be slow enough to overheat it or do I need to thoroughly clean fuel system - tank, screen, lines, carb. I guess it is running lean? I hope it's not valves or compression. To my knowledge the head has never been removed, nor the valve cover.

Any opinions? It also hunted while warming up, but stopped when warm and ran smooth under load.

 

[KC_kid]

To me, this is mind boggling:
Engine starts easy and runs good, until it slowly dies after decent use and you find it is overheated.
Or, it mows your whole yard perfect and when done, you find it's overheated.

I don't get it, supposed to be an easy, reliable engine. I still believe that, even though this HR215 K1 turned 14 in April. Hydro trans works absolutely perfect. Deck is as solid as the day it was cast. Operates smooth and easy, until the overheat!!

edit: using 30Wsae oil, I think per manual.

 

[BlazNT]

Time to clean the carb with carb cleaner and compressed air. Check float and needle valve for proper movement.

 

[robert@honda]

To me, this is mind boggling:
Engine starts easy and runs good, until it slowly dies after decent use and you find it is overheated.
Or, it mows your whole yard perfect and when done, you find it's overheated.

You say it is overheating...what are the exact symptoms that it is overheating? Just smell and smoke from the oil filler? Anything else?

How about the breather tube between the air cleaner case and the engine block? This is supposed to vent fumes and positive air pressure from the crankcase. If it were blocked, excessive pressure could force oil out from the seals, or perhaps "poof" a bit of smoke when removing the dipstick? Just a guess, but can you confirm the breather tube is not bent, kinked, and is clear?

 

[motoman]

KC, Read the plug. (consult any auto repair book for pictures of over lean condition) .Borrow an infrared temp gun and perhaps the pro's will advise expected head temp. I measured 310F on my intek at the sparkplug . The sump oil runs up to 300F. You probably cannot judge "overheat" just because of smoke. Worn ring/bore allows oil into the chamber to smoke under normal temps. Pro's will chime in...

 

[KC_kid]

I didn't see anything too crazy with the plug, although I can't read them well and looking at diagnosis pictures didn't get me anywhere.
Breather tube is confirmed clean, clear and not kinked. I pulled it off tonight to inspect.

I will clean out full system this weekend and use brand new gas. It's odd to me that the same thing happens on 2 different carbs.

The symptoms are engine dying and can't restart till it sits for a while. Also smoke will come out off the top of the engine, from under the red cover when it shuts off. Smoke also comes out of the dipstick tube and when you pull the recoil, it will puff smoke out as the piston strokes. Smoke doesn't roll out but it's not a small puff either, it will smoke a decent amount. Smells hot. The oil was burnt when I changed it last, black, and it was low after only maybe 10 hours of use because some of it burnt off. I will check temps with IR thermometer during next mow. I thought of that last time but didn't know what temps to look for, thanks for that info.

 

[exotion]

Have you adjusted valves? Exhaust valve could be we bit to tight

 

[KC_kid]

Have you adjusted valves? Exhaust valve could be we bit to tight

I have not adjusted valves or taken off valve cover for inspection. I may pop the cover for inspection and pictures, when I am flushing fuel/ cleaning carb this weekend.