Ordering a pulley for my QA42A, need to make sure it's the right one

[jimbob200521]

Long story short, I believe my 682's Series I KT17 finally gave up the ghost yesterday so now in an effort to keep my snow moving equipment running, I am going to transfer the QA42A to my 14hp 129. So that means I need to get a new 1/2 pulley for it and order a belt. I'm looking around on McMaster-Carr.com and have settled on part number 6204k22.

http://www.mcmaster.com/#v-belt-pulleys/=q7yfx9

I selected a cast iron 4.15" pulley with a 3/4 bore to use. I believe in looking around online, this is the pulley many have used on there machines but want to make sure. Also, what is pitch dia and how would it effect my setup (i.e. did I pick a pulley with the right 3.4" pitch dia. for a type A belt)? Does anyone who's ordered these pulleys from mcmastercarr know if they have set screws in them?

Next up, since I'm getting a slightly smaller pulley (4.15" vs 4.5"), what's a good belt size to use? Would a 30" 1/2" belt work for me or should I go smaller? Any words of advice would be greatly appreciated, thanks!!

[J-Mech]

Why do you think you blew the motor?

It will come with set screws, and you can't pick a pulley by pitch diameter. The one you picked is fine.

[jimbob200521]

Originally Posted by J-Mech

Why do you think you blew the motor?

I haven't had a whole lot of time to check into it but yesterday afternoon we used it to drag the Christmas tree out to the burn pile and when I was on my way back to the garage, something started sounding...not right. It started having trouble holding RPM, the lower the throttle the more unsteady it sounded. I had to throttle up and even feather the choke a bit to keep it running. It sounded really, really rough. I'm not sure if it'd be a lifter or possibly rod but it really sounded like it was running on one cylinder by the time I got it back into the garage. When I started to idle down, it just chugged and died. I checked all fuel connections, I checked the oil for gas, I checked spark plugs/all other electrical connections, and removed the air filter. After cranking, all I got was smoke out of the exhaust and it was coming back up through the carb pretty heavily, too.

Now that I think it matters, when I was at work with her last week cleaning up some parking spots after the weather reached positive digits again, it started to sound, I don't know if this is a good descriptive term, but when I'd load the thrower up, it would sound like it was growling, almost very throaty when she'd work hard. I figured it was just because I was working her good with the snow but now I'm not so sure. I took a flashlight and looked around without removing any tin and I didn't see anything and there's no oil leaking, but as she sits right now, she's a broken tractor that won't run