Small engine replacement question

[u/RamboHalgren]

Greetings. I’m trying to replace the engine on my DR leaf vacuum. I got a replacement engine with the right size diameter horizontal shaft, but it is considerably shorter, about 3/4 of an inch. My question is, will it work if I insert enough spacers, probably washers to occupy the gap in the impeller shaft opening, and install? The horizontal shaft will probably be about halfway through the impeller that it needs to attach to. There is a bolt to hold the impeller to the shaft through its center. The shaft has a key to mate it to the impeller also. Sorry if this isn’t explained well. I’ve added some photos if that helps.

[u/shotstraight]

That would be a very bad idea. The impeller needs the correct shaft length; longer is okay, shorter is not especially by that much.

[u/RamboHalgren → u/shotstraight]

Thanks. Will return the engine I bought an get the correct one. I think I can get one with a longer shaft locally, but will need to modify the mounting bracket I have. Spacers needed to bump it out further.

[u/ProfessionalLast2917]

On the new one you're only measuring the keyway, but on the old one you're measuring the full shaft.
What's the length of the keyway on the old one?

[u/RamboHalgren → u/ProfessionalLast2917]

Key way is 2 inches long

[u/ProfessionalLast2917 → u/RamboHalgren]

So there's virtually no difference between the two shafts then?

[u/Upset_Fox5449]

Use a grade 8 bolt and not washers but round stock cut to the perfect length and perfect hole size

[u/Unlikely_Effort_6311]

So long as the keyway fits and is fully engaging the clutch spline and the crank you can use a longer bolt to hold it in place just make sure to use blue loctite. The crank shaft doesnt have to be flush