Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

danen_inc

Check your receipt, but in the U.S. Lowe’s has a 30 day return policy for power equipment. Just pack everything up and take it back to the store. You don’t even need a reason for returning it, but the fact that it’s missing parts and damaged is full justification in anyone’s book. Have them give you another 928 and have them set it up.

The John Deere is made by Simplicity, which has about as good a reputation as any brand of snow thrower. Likely the crate for yours was damaged in shipping and some parts dropped out somewhere. That’s why I would have Lowe’s set it up. You can double check the setup when you get the 928 home. However, if you want to set it up yourself, inspect the next create for any damage before you take it home.

Mac

The JD 928e uses the B&S 305cc Snow Series engine model number 200000. This engine is rated at 13.5 ft-lbs. of torque in accordance with SAE J1995. Under that standard torque is measured at 3060 RPM and horsepower is measured at 3600 RPM. If we assume a flat torque curve, which is not likely, you can calculate horsepower using the following equation.

HP = Torque ft-lbs. x RPM / 5252

Substituting the values you would get the following.

(13.5 x 3600) / 5252, which is 48600 / 5252, which is 9.25 horsepower.

It’s likely that torque is less than 13.5 at 3600 RPM, so I would round this off to 9 horsepower. Now you know where the 9 in 928 comes from, and the 28 is the width in inches.

By the way, to get 11 horsepower you would need 16.0 ft-lbs. Torque at 3600 RPM. To get another 2 HP out of this engine at the same RPM requires getting more air/fuel into it. That usually means either a bigger carburetor and/or a less restrictive exhaust system and/or a different cam profile. However, B&S could just put a stop or different linkage on the 9 HP engine that prevents the throttle from opening 100%. Why, it’s all in marketing. Customers are willing to pay more for more HP, but it’s cheaper to have fewer engine models. The solution is to build a 11 HP engine and then limit the maximum throttle setting for the 9 HP model. Then again, maybe there is no difference at all and the 9 HP is really the 11 HP engine, but it’s only marketed as 9HP. You would need a dynamo to figure it out.

I don't know what method B&S uses to change the HP of otherwise identical engines, but it could be nothing more than some linkage going into one hole of a plate attached to the shaft of the throttle butterfly on the 9 HP engine and that same linkage going into a different hole on the 10 or 11 HP engine. You wouldn’t be able to tell this from looking at the part numbers as they are all the same, it’s just what hole the linkage goes into. On the 9 HP engine, that set up limits the throttle opening to just 82% of full open, which knocks off 2 HP. I don’t know if this is how B&S does it, but it would explain how otherwise identical engines can have different power outputs.

The advantage for B&S is they can easily span a large HP range with just a few engines, which means they can reduce the cost of those engines. It’s also means dealers have to keep fewer parts in inventory. Likely there’s an easy means to get the maximum power out of one of these engines, but if you have a drive system, impeller and auger designed to handle 9 HP it’s really not a good idea to put 11 HP into it.

Then again, as I said in Reply #14, "maybe there is no difference at all and the 9 HP is really the 11 HP engine." I certainly wouldn’t fee ripped off by getting 11 HP for the price of 9 HP if the rest of the machine can handle it.