K21 Deliveries

[Tim Kish]

Actually still have them on the bench. Was thinking about taking them apart to see what the balls and races look like.
Radius’ look the same on both

Actually still have them on the bench. Was thinking about taking them apart to see what the balls and races look like.
Radius’ look the same on both sides.
View attachment 324464View attachment 324465View attachment 324466

Some manufacturers do , some don't.

 

[Buckshot]

Do they have a brand name on them? Steel cage? Tabbed or riveted?

Are you sure the bearings are fully seated in their pockets?

They were NTN. Tabbed.
Yes I’m positive they are fully seated.

 

[Buckshot]

Those used bearings look good for more than 4 gallons of fuel.

I feel like I could have left them in, motor ran great before I took them out.

 

[Terry Keeley]

Any way to measure the distance between the step at the front of the crank to the back of the counterweight? Then the corresponding distance in the case?

Even a rough measurement with calipers would tell you if that's the issue or whether it's bearing fit related.

If it is the cause of the problem a simple fix would be to make a shim to fit between the step on the front of the crank and the inner race of the front bearing.

 

[tnrcboatracer]

Terry, adding a shim to the crank will allow the crank to float rearward towards the drum. Maybe NG.....

 

[Terry Keeley]

Terry, adding a shim to the crank will allow the crank to float rearward towards the drum. Maybe NG.....

Ya, you'd have to check the clearance between the drum and crank but most motors have 0.025" or more.

I'm talking about a 10 thou shim. If the reason there's no end play is in fact that the inner races are being pressed into the outer races due to the crank being too "short" that would fix it.

I do think it's probably something else tho, if that were the case the rear bearing would have little or no internal clearance as well and there's no way it would last for four gallons of fuel, especially the way Buck ran it.

Probably too tight a fit on the front bearing, either the crank, case or the bearings themselves are oversize or are only C2 or less to begin with. Someone needs to have a good look at with a decent mic and bore gage and have the specs for the bearings.

Is there end play when you install the WIB C3's?

 

[Bengt Bjorkhage]

I am starting to receive deliveries of the K21 engines. They are coming in slowly as he can only make 5 to 10 engines per week, given the situation in Ukraine.

The K21 comes with a cable collet for 3/16" cable and two head buttons. One head button is for a standard glow plug and one is for a turbo plug.
The engine does not come with a carburetor. A CMB 21 bolt on carb works well and Speedmaster makes a carb as well.

The K21 price is $350.00 plus $17.00 for Priority mail.

The bearings are adequate, but not the best. I suggest replacing the large bearing before you start racing. I can include #6000 WIB bearing for $12.00.

The original K21 test engines performed well, beyond expectations. After delivering over 100 of the K45 engines without any reported failures and zero complaints, I expect the K21 to be a favorite for both sport and race drivers.

If you want one of the K21 engines please send me a check or money order and your mailing address address. I will not de[posit your payment until your engine is ready to ship.

Again, they are coming in slowly. I have ordered 100 of the K21 engines and at the rate I am receiving them, I expect to have received the complete order in April or May.

Al Hobbs
2402 Old US Highway 91
Cascade, Montana
59421

Hallo Al
I have order k21 and k45 from you compel on ebay

We have test the keps 21 3dprinted an it runs very good
in begining of may i should test the keps 45 3dprinted

Best Regards
Bengt Björkhage

 

[Bengt Bjorkhage]

I am starting to receive deliveries of the K21 engines. They are coming in slowly as he can only make 5 to 10 engines per week, given the situation in Ukraine.

The K21 comes with a cable collet for 3/16" cable and two head buttons. One head button is for a standard glow plug and one is for a turbo plug.
The engine does not come with a carburetor. A CMB 21 bolt on carb works well and Speedmaster makes a carb as well.

The K21 price is $350.00 plus $17.00 for Priority mail.

The bearings are adequate, but not the best. I suggest replacing the large bearing before you start racing. I can include #6000 WIB bearing for $12.00.

The original K21 test engines performed well, beyond expectations. After delivering over 100 of the K45 engines without any reported failures and zero complaints, I expect the K21 to be a favorite for both sport and race drivers.

If you want one of the K21 engines please send me a check or money order and your mailing address address. I will not de[posit your payment until your engine is ready to ship.

Again, they are coming in slowly. I have ordered 100 of the K21 engines and at the rate I am receiving them, I expect to have received the complete order in April or May.

Al Hobbs
2402 Old US Highway 91
Cascade, Montana
59421

Hallo Al
Here is a video of the first test of the keps21 3dprinted an a new os 21
Bengt

 

[Al Hobbs]

The K21 small bearing is recessed 0.040". If you only press the bearing in even with the crankcase, the bearing is not fully seated.