(Another) Dumb Question
 

I've read over and over on many different posts about air leaks in your carb or having the wrong carb adjustments making the engine run lean can cause overheating.
The dumb question is, if the tractor seems to be running great, how do you know if it is running lean? :Huh:

Pull the spark plug and post a pic of it. Obviously the pic you post need to be of the end that goes in the engine.

Heres a little chart.

:ROTF2: Good one!

Adjust it until it blows smoke on a quick rev, then back it off just a little. Rich is better than lean on an air cooled motor. Obviously, you don't want it so rich it carbons the combustion chamber with coal black soot... but it needs to be on the rich side.

See, sometimes you just overlook the obvious. I'll pull the spark plug and post a pic of the end that goes into the engine. :biggrin2:

Thanks, that's what I want. It really runs great for 1 3/4 hours solid. Then acts like it's starving for fuel. I've been tweaking a new carburetor.

Here's the plug. Without cleaning it, the gap is .030.

Attachment 93335

Here's some info on reading the spark plug.

http://www.ngksparkplugs.com/about-n...d-a-spark-plug

Thanks, I appreciate it. My spark plug looks normal to me.

I would richen the carb just a hair and throw a new plug in it.

Not sure how long you ran it in the engine. Amount of time run and at what RPM would make a difference. I would call that going towards the lean side just a little.. Is this a twin? if so how does the other look in comparison?

You are on the lean side. I agree with Tim, give it some more fuel.
I would also be checking the air filter and filter housing. Either the engine is burning a bit of oil, or it is getting a bit of dirty air. Looks to me like it's getting dirty air. How loose is the throttle shaft? A loose throttle shaft will make it run lean, and suck in dirty air.

Generally better to err on the side of rich....!

You must not have seen post #7. It's a new carburetor. It now has a new shut off valve, filter, fuel line, air filter and pre-filter, and spark plug. That plug was in it with a carburetor with a worn throttle shaft and the old air filter.

Yup, put a new plug in it. 3-4 hours of regular use and have another look

I just put a new plug in it. This is a 1250 with a Kohler K-301 AQS engine.

We'll look for a new picture in about a week :-)

Yes, I need to mow but we had a downpour today. Hope it dries off enough tomorrow. It takes me two hours to mow. We'll see.

I did miss that.
I bet that's why the plug looks like that then....:BlahBlah:

Ran the 1250
 

The Cub did great today. Mowed for just under 2 hours non-stop. Here's a pic of some of the yard, the Cub is by the garage. It's a little over an acre with three buildings, trees, trees, and more trees.

https://i.imgur.com/N4EjFqt.jpg?1 https://i.imgur.com/TTwjYj9.jpg?1

But, I did wear this cap this time. Maybe that had something to do with it!

https://i.imgur.com/xNhLVsl.jpg?1

Yard looks great!.. 2 plus hours is a good amount to burn some fuel and engine hot.. Hows the plug look?

Okay, I'm burning the midnight oil. I knew that. I'll keep my eye on it. :NailBite:

https://i.imgur.com/CFXwpdR.jpg?1

Nice yard Rocky. Where did you get the original hat from? Got a link?

Looks good, but it was probably too soon to pull it to see. Looking at plug color is an indicator to how it is fueling, but not a choice method, or "procedure" used to tune. You can check carb tune without pulling a plug.

Yes, what can i say? I just couldn't wait to see what the brand new plug looked like after adjustments.
How often do you check the timing? I do the static timing. Honestly, I haven't checked it for awhile. I have no idea how to read the hour meter. It's 42 years old. It has a few hours on it, and who knows how many previous owners.

Once the timing is set, I'd say it shouldn't need checked but only maybe every 150 hours. You could make it part of the tune up and check it when you change the spark plug. But only need to do that on about the same interval. By true hours of operation, 150 hours isn't that many, but most people it takes 2-3 years to put that many on a tractor. Pull it every few years, if it looks good, clean it and put it back in. When it shows wear, replace it. I'm not one of those guys who thinks they need replaced before they are worn out. I don't remember the last time I even had the plugs out of any of mine.

Thanks, Jonathan. This has been a great tractor. Stuff started to show up after adding the new carb, mostly just tweaking. But the clogged shut-off valve was unexpected.
By the way, did you get my reply to your PM?

I bought it 6 or 7 years ago. I looked real quick and didn't see them. Maybe contact them. http://www.tractorhats.com

I did. Just a lot going on. Bad week. :beerchug:

Just wanted to make sure I did it right. Moving on. Hope things get better for you. :ThumbsUp: