LawnBoy overheating?

I have a LawnBoy 10415 Gold Series 4.5hp 2-cycle lawnmower.

I bought it at a garage sale at the beginning of the season last year. It worked great for most of the season, but in August when it started getting really hot I started to have problems.

It would always start first or second time, but after about 10 mins of mowing it would cut out/stall. You would hear it struggling just before it did, normally as you went over a deep bit of grass. if you hear it struggle and quickly lift it up (so it has less work to do) it will keep going for another minute or 2 , but eventually it will stall even if you are just running it on the sidewalk with no work to do.

Once it has stalled you can't immediately restart it as the blade seems to have locked in position. If you tip it on its side and rotate the blade by hand you can free it up. After doing this it normally restarts and runs for maybe 1 or 2 more minutes and then cuts out again ( same thing with the blade locked again)

I am an amateur at this sort of stuff but happy to get my hands dirty and would like to learn how to fix it. Any idea what the problem could be and is it something I could attempt to fix? Or should I just take it to a professional?

Firstly check to see if there is any damage to the cooling fins on the engine. If some cooling fins have snapped off the engine will not cool down properly. Also, is there any debris or grass around the engine on the deck? Make sure the deck is spotless and there is no grass stuck in the cooling parts of the engine.
If this is all okay what is the condition of your blade? A damaged or blunt blade won't cut grass correctly and the engine will be working hard.

What kind of oil are you mxing in with your gas?
A lean fuel air mixture could cause this also.
There is a lawn boy expert (twostroke who will be along shortly, I'm sure he will know what is wrong with your Lawn Boy. He collects them and probably has one just like yours

clean exhuast port/muffler area. may be on the bottom of deck on that model, could be carbon build up, also coil could be getting hot.

i reread your post and also could be coming apart inside, early sign of improper gas mix or just plain getting tired. Rob berring going bad?

I've got a model 10415 as well. Sorry to hear that you're having problems.

I'd try everything recommended above -- particularly cleaning the cooling fins and the muffler -- although a clogged muffler problem usually takes a long time to develop and it sounds like this thing came up quickly.

I would also make sure that the air filter is clean.

Welcome to the forum -- note that there's a Lawn-Boy forum here also and there are a few of us who are hard-core LB hobbyists.

Thanks for all the feedback!

I have been using Sta-bil mixed with E85. Home Depot told me that's all I need to add? Is that right?

In terms of blade condition and cleanliness... It's a bit worn, I plan to replace the Blade and clean the exhaust ports etc. before I start using it this year. I will thoroughly clean all over and check cooling fins as well.

DUDE!!!! Sta-bil is not two stroke oil! You have been running straight gas through it. Sta-bil is a fuel stabilizer. You need to buy a two stroke oil and mix it in your gas. If you don't know the correct ratio, either find out or use a product like OPTI-2.

OMG! Now I feel stupid. Really shouldn't listen to the guys at Home Depot!

Do you think I have done some damage or could it be fixed?

I would think some damage has already ocurred, but if you put the two stroke mixed fuel in it and it runs, I would not stress about it right now. Hopefully there was enough residual oil in it from previous uses to protect it a little. The one good thing about two strokes is if there is any damage that would effect its running ability, it will show up quick. These engines require a high amount of compression to run and if everything ain't kosher, it won't work. Good luck.