I just need to share this story with some folks that understand the sense of accomplishment that comes from working something out with your own two hands.
A couple weeks back, I had an entirely self-inflicted problem with my push lawnmower. As it turns out, I had every tool I needed to fix it already on hand. This is the first complicated repair I've done that didn't require at least one run to the store for tools. I feel good about that.
I'd sharpened the blade in the mower for about the 8th or 10th time and I guess that was too many. She ran a little rough. I got two mows out of it, then she wouldn't start. I assume because the blade was too far out of balance. I didn't originally think the blade, so I swapped in an old (but good) spark plug, played around with some other stuff. Air filter, etc. When I went to pull off the muffler to check if it was blocked, one of the bolts snapped. %^!!#$%! Self-inflicted wound #1.
I took her inside and did some disassembly and tried a couple different styles of Easy-out. No luck. Hmmmm.........
I thought, "Hey, I've got a drill press, I can do this." So I started disassembling to get the motor off the deck. The motor bolts were rusted from 6 years stored under the back deck.... and - based on some Internet research - may have been held in with red Loctite... the kind you need to heat to remove. My impact gun was not doing anything on them, so out comes the 30" cheater bar.... You can see where this is going. Twiiiiiiiiiiist SNAP %#!^!^#%!! Self-inflicted wound #2.
At this point, I saw how things were going, so I just self inflicted wounds #3 and #4 on the other two motor bolts.
Great. So now I have a mower motor with four bolts broken off flush with their respective surfaces. But I've got a drill press. What sizes do I need to make these holes? The muffler was held on with two bolts, only one of which broke. My Rockler Thread Detective told me the muffler bolt was a 1/4-20. Great! I happen to have a 1/4-20 drill and tap.
The other bolts were a little tougher because I did not have an intact example. I did a little quick Googling. Based on the wrench size (1/2") I guessed these were 5/16-?? bolts. Great! I happen to have a 5/16-18 drill and tap.
My drill press only goes down to 300 rpm, which isn't ideal, but it worked ok. I ended up using a couple 24" clamps and a couple 36" clamps to clamp the motor into some 6" car cribbing I had on hand (Example - Not my image) so that the motor could be squared to the quill and secured to the table.
1 hole ended up just about perfect. 1 hole ended up pretty good. 1 hole ended up "good enough to make work". The 4th hole, unfortunately the one for the muffler, I just couldn't get it to set in the correct place and just ended up drilling it anyway. They all threaded up beautifully, though. It would've been easier with a ratcheting tap wrench, but I don't have one. I ended up using an old sliding-T handle style breaker bar that I got out of a Craigslist toolbox purchase, a 6" extension, and an 8-point socket (also out of a Craigslist toolbox purchase) to drive the 5/16-18 tap.
Ran to the store for a new spark plug, new blade ($23 ain't bad in my mind), new oil (store sold 20oz bottles for $4.79... right next to 1 quart bottles, also for $4.79 ), and 3 new stainless steel 5/16-18 bolts and lock washers. I tried to find a stainless steel muffler bolt, but it was a weird shoulder bolt w/ a 3/8" shoulder. All the store had for 1/4-20 bolts was 1/4" shoulders.... the 3/8" shoulders were 5/16-18 threads. I can get them from McMaster - for $10.xx per bolt. I ended up just putting the one bolt in and tightening it down really good.
I started putting everything back together. Wife came down and asked me what I want for dinner. And I drop a screw down into the housing. #^!&%&!^# I say "Great, now I have to take all this stuff apart to get that screw out!" Wife says "Why don't we just buy a new mower?" Says I.
This time, I liberally apply PB Blaster to every single bolt that I'll even think about removing. Everything goes smoothly.
I put it all back together again (without dropping anything). Put on the new blade. Popped in the new plug. All new oil. Put about a 1/4 tank of gas in (not NEW gas, but only in the can for probably a month, I've never had fuel issues with any of my equipment). Rolled her out of the garage and into the drive... in case things went pear shaped. PULL! Puff-Bump-WHIIIIIIIIIIIIIIIIIIIRRRRRRRRRR.
Dang thing started up first pull!
And the blade didn't go flying off and chop off my feet.
She's just a tiny bit louder than before, so the muffler probably isn't sealing 100%. But it's sealed enough so that the auto-choke thermostat works and that's all I care about. Total out of pocket was $23 blade, $2.50 spark plug, $5 for oil (but I've still got about 24oz left), and $5 for bolts.
tl;dr - Broke some bolts on the mower. Drilled and tapped new holes. Reassembled and started first pull.