Did you compare the new belt and cable with the old ones. No real adjustment on these. How about engine RPM?? Over speeding the engine would cause a faster speed. The newer machines always sound like they're not spinning fast enough, but they are. I would check the throttle speed.

I have one of those 6.75 self propelled craftsmans. Yes they are fast. They are great out on open lawn but not too great for trimming because of the speed. Backing off the throttle will help but then you loss power and these 6.75HP's run like a 3.5HP. Mine is front wheel drive so I just push down on the handle to stop the thing when trimming. I don't use mine too much, I let the wife use it. It keeps her off my tractors and the fast speed is good for her big butt.

I used the correct cable,belt and the engine speed is also correct. You would think Sears would offer different drive gears or pulley's to slow it down. I am very spoiled as I have two John Deere JX75's and they are way, way better. Yes, they cost a lot more but you get much better quality. I was hoping to have a nice inexpensive mower but it just propels to fast. The story behind the Sears mower is this. While at a garage sale, I took a second look at this like new mower and the women say's "You want it, take it free" My husband has had it with it" Honestly, the mower looks brand new! I serviced it with new oil, air filter, plug, blade, belt, cable and new grass bag. Great looking mower, starts first pull but be ready to run like heck to cut your lawn!
Thanks for the input.

JTFS, My late father bought one of these a few years ago & I use it occasionally, I too notice that It moves too fast for me I'm 56, But I did find that If you only engage the lift bar a little bit instead of all the way it will move slower and does not effect the engine speed.
Post how it works for you.
Glenn

You Got To Be Kidding Me! After discussion here regarding the self propell speed, which is way to fast, I have since found out this is a typical complaint on this mower. I took the mower out this past weekend and found this mower to be a complete joke! The wheels are spinning like crazy and when the wheels do grip it's a complete chore to keep the mower straight. Meaning.. the wheels are going real fast and if the left one grabs, well, it pulls left and if the right wheel grabs, well, now it wants to go right. A complete struggle to cut the lawn and forget going up hills. The trick is to run with this mower and keep up with the self propell speed amd it works just fine! Very sad that this mower is on the market. I will say, the B&S 6.75 HP motor does run great but the self propell is a very poor design.

I agree too that the self propel is a poor design, I too have to move preety fast to keep up with it, So know I only use it when I'm in a hurry to get the grass cut !!!

Glenn

I have a new Craftsman Power-Propelled mower. It has a Briggs 6.75 hp engine and is a 22" cut. Model No. 917.376450. Mine may be different than what you guys are discussing but I am able to control the speed of the mower by backing off a little on the drive bar to slow it down.

I have a new mower with the same problem. I am going to try and attach a spacer to the handle do the throttle won’t be full open. Maybe a device I can turn for, say, 3 speed. but it’s 1 day old, so I’ll consult the manu. First.

having decided that slowing the mower by the throttle cable, or not quite engaging the power to the wheel seem less doable than changing the pulley, and, no doubt, the belt, I guess that's the way to go. I don't know, however, how it is built because I haven't looked. How is the pulley attached? How could I know what size pulley or belt is correct for the speed I want? Which Pulley would be the one to change, given all the information needed? Are there any pictures, schematics or layouts of the drive design I might consult in advance? That always helps me when I build amplifiers from scratch. I know when I'm ignorant! thanks for any help.

The speed difference (Revolutions per second) is the ratio between the diameters of the pulleys, or the ratio of the perimeters of the pulleys (PI* diameter) If Pulley A is the same diameter as B, they will run at the same speed. It A is twice the diameter of B, B will run twice as fast. If A is half the diameter of B, B will run half as fast.

The only other consideration is the space for the pulley, You obviously can not double the size of a pulley if it then is rubbing on the deck.

I just bought one of these used, a 917.377190 in decent shape. Off and on for the last couple of months, I've been working on it, the usual maintenence, snuffing it up. The self propel speed does stand out, and is a real problem for what I use it for, mostly trimming my yard where the riding mower can't go. Literally have to run after it. The front wheels are burning rubber all the time. I've found that some Craftsman items seemed to be designed to fit under a price point, and this appears to be one of those things. No self propel speed or engine speed controls.

The only way I found to remedy this problem was to adjust the governor spring adjusting lever at the carb flange by bending it back as far as it will reasonably go. This brought the engine rpm down to about 2150 rpm. The propel speed is now at least reasonable. How far back the governor lever on the engine itself will go is limited by the crankcase breather fitting under the front of the fuel tank.

To bring the RPM down a skosh further, I might try bending and shortening the Governor lever to carb throttle link slightly.

A razor sharp blade is a must, if it's going to cut grass at this engine running speed. A clean carb is also a must, with a dirty or gummed up carb, it will surge.

The Sears manual can be handy, it has a parts ID list. https://www.manualslib.com/products/Craftsman-917-377190-2883166.html