I am working on installing a new Harbor Freight 6.5 HP engine in place of an old B&H 5HP engine on a turf vacuum. Everything has been going fairly well (with the exception of a major modification to the exhaust system that I was required to make to get it to fit) except that when I went to install the impeller fan on the crankshaft, it slides so far onto the crankshaft that it actually bottoms the fan out on the housing before the fan bottoms out on the shaft. So of course, the fan won't spin like that.
I am like 80% sure that I have it all installed correctly, so my question is, is there some way to put a spacer or something on a crankshaft to hold the components out farther away from the engine?
At this point, about the only thing I can think of is finding a fat stack of washers with a 3/4" ID but that sounds a little too redneck for a brand new engine - even if it is a HF turd. Any alternatives or tricks out there?

you will need to find a locking ring, the ring will have 2 set screws on one side. otherwise the washers will rub on the block. try the local hardware store for this item.

Great - thank you.

Are those rings a generic piece, or are they designed for small engines? Aluminum or steel?

I found some locking collars on Grainger and would like your input on which you think would stay put on the shaft the best without eventually loosening or sliding back. There was a "set screw" one like this:
http://images.grainger.com/B279_33/images/products/small/SMALL-2X569.JPG

And there is a 2-screw "clamp style" one like this:
http://images.grainger.com/B279_33/images/products/small/SMALL-1L692.JPG

Which would hold better? I'm thinking that the clamp style would work better...but if I were to put a little hole in the crankshaft for the set screw type, there is no way that one would move...

Or I could just get a couple of them and use them as spacers against the "necked down" portion of the crankshaft - that way, even if they slid back a bit, they wouldn't rub the block...thoughts?

At this point, about the only thing I can think of is finding a fat stack of washers with a 3/4" ID but that sounds a little too redneck for a brand new engine - even if it is a HF turd. Any alternatives or tricks out there?

Some mowers do use spacers inside the blade adapter to lower the mower blade. Redneck or not all the spacers amount to are thick washers. If you can find something that will fit inside the impeller you could take up some space this way, just remember that the mounting bolt must be long enough to engage the crankshaft properly so as to properly hold the impeller.

Thanks for the comments

If you can find something that will fit inside the impeller you could take up some space this way
I'm assuming you mean behind the impeller? Because the impeller fits snugly on the shaft and there is no getting anything inside there...


just remember that the mounting bolt must be long enough to engage the crankshaft properly so as to properly hold the impeller.

The mounting bolt is plenty long enough, I won't use the collars to move the impeller out beyond where it needs to be - just to keep it from sliding too far onto the shaft and into the blower housing.

Those Rednecks can get years of service out of something most people would consider junk. Have a good one. Geo

Those Rednecks can get years of service out of something most people would consider junk. Have a good one. Geo

Thanks, I will see if I can pick one up for use around the farm.

BTW, here is my "redneck" fix on the muffler:

Muffler flange won't fit due to interference w/ blower housing:
http://i111.photobucket.com/albums/n150/joedola/Misc/Photo_030309_001r.jpg

Flange cut off and handlebar tubing insert:
http://i111.photobucket.com/albums/n150/joedola/Misc/Photo_030309_008.jpg

Fits like a glove:
http://i111.photobucket.com/albums/n150/joedola/Misc/Photo_030309_010.jpg

Thanks for the comments


I'm assuming you mean behind the impeller? Because the impeller fits snugly on the shaft and there is no getting anything inside there...

Nope! I mean inside where the impeller slides on the shaft. Of course this won't work if the end of the impeller is open and does not have anything that butts up against the end of the crankshaft. Good looking muffler mod.

Nope! I mean inside where the impeller slides on the shaft. Of course this won't work if the end of the impeller is open and does not have anything that butts up against the end of the crankshaft. Good looking muffler mod.

OK, I see where you were going with that - no, the end of the impeller is open, so that won't work. Thanks for the compliment. It was a minor mod, but the 3D nature of it required a lot of test-fitting/grinding to get it aligned.

I like the exhaust header you created, now it's a hot rod. Have a good one. Geo

I like the exhaust header you created, now it's a hot rod. Have a good one. Geo

ya thats a DERN GOOD IDEAR :D

OK, I bought the collar from Grainger and this is what I got - they come in a pack of 3 for just under $8.00:
http://i111.photobucket.com/albums/n150/joedola/Photo_030709_002.jpg

This is one of them installed - you can see I just needed a bit of clearance so that the fan wouldn't rub on the bolt heads. The "set" screw on the collar fit in just right so that it is actually digging into the groove for the woodruff key. This actually uses the slope of the end of the groove to push the collar into the impeller fan. I also used RTV black as a locktite substitute on the set screw - I hope that one doesn't come back to bite me in the keister. The fan sits about 1/8" to 3/16" out farther than it used to, so I installed a new crankshaft bolt that is just a bit longer to make sure I am engaging with enough of the crankshaft threads:
http://i111.photobucket.com/albums/n150/joedola/Photo_030709_003.jpg

Impeller fan installed:
http://i111.photobucket.com/albums/n150/joedola/Photo_030709_004.jpg

Buttoning it up:
http://i111.photobucket.com/albums/n150/joedola/Photo_030709_005.jpg

Done deal:
http://i111.photobucket.com/albums/n150/joedola/Photo_030709_006.jpg

We fired it up and it works great. The thing sounds like a chopper is about to take off when you crank up the RPMs, but it does work great. I know this because the kids accidentally left my gloves up near the sucker and "phlatph phlatph" they were "in the bag."

Now to the next problem. There are two safety interlock switches on the machine. One to make sure the bag is in place and one to make sure the suction fitting is in place. Supposedly, if either one is missing, the engine should be disabled. I have confirmed that the switches are "open" when the parts are missing and "closed" when the parts are installed.

Conversely, I have confirmed that the wire that I tapped into on the HF engine at the on/off switch is one that only kills the engine when it is closed. So my conundrum is this:

If the on/off switch wire has to be "closed" to kill the engine and the safety intelock switches have to be "open" to kill the engine, how do I get the two of them to play nicely together? Right now, I can't get my feeble mind to grasp a way to make the safety interlock switches work with this wire on the engine. Does that make any sense?

What kind of engine was on it originally? Almost all small engines are short to ground to kill.

What kind of engine was on it originally? Almost all small engines are short to ground to kill.

It was a B&H. This HF motor appears to be short to ground to kill as well. That is why I said that "the wire that I tapped into on the HF engine at the on/off switch is one that only kills the engine when it is closed."

Is there maybe another wire somewhere that has to be hot for the engine to run?

It was a B&H.

Do you mean a Briggs and Stratton?

The wire you need to tap into to kill the engine would be the one listed as (Black) that plugs into the coil, before the kill switch plugs in, on the attached wiring diagram for your engine.

Do you mean a Briggs and Stratton?

Ooops - yes B&S

Thanks for the diagram. I'll take a look at it and try to find a way to make this work. It is looking like I tapped into the wrong circuit.