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Feb 24, 2020, 12:41 AM
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K&B 6.5CC DF motor, It lives! :)


Hey engine nuts, before I destroy this nice little engine that needs new bearings;

1.How do you take the front machined Alu. hub off?
2. Can one change it to different short hub, and is it available, to make it into a prop plane engine?
Last edited by Sam Ehab; Mar 03, 2020 at 09:00 PM.
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Feb 24, 2020, 01:46 AM
AMA 46133
SeismicCWave's Avatar
Quote:
Originally Posted by Sam Ehab
Hey engine nuts, before I destroy this nice little engine that needs new bearings;

1.How do you take the front machined Alu. hub off?
2. Can one change it to different short hub, and is it available, to make it into a prop plane engine?
If the KBV 82 is any indication I would say probably a tapered collet is holding the prop drive hub.

The closest thing I found is a K & B .48 ducted fan engine in MECOA. Here is a link to the exploded diagram and yes it is a tapered collet holding the prop drive hub.

http://www.mecoa.com/kb/48/4825-exp.pdf

MECOA also has a K & B .48 aero engine listed. Here is the exploded diagram.

http://www.mecoa.com/kb/48/4800-exp.pdf

So in theory you can get the collet and the drive hub for the aero engine and fit it on the ducted fan? Ok you don't even need to change the collet. They are both the same part number. Just buy the shorter drive hub for the aero engine 20-4801 and you should be able to use a prop on it.
Feb 24, 2020, 02:00 AM
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Thx man. I did look at the Meccoa site and didn't even see the 6.5CC, they had the 7.5CC so I wasn't quite sure. Although I suspect the 6.5CC and the 7.5CC may share many parts. I'll order some bearings soon and check out that 20-4801
Feb 24, 2020, 06:04 AM
GloBroz PowerLab
1QwkSport2.5r's Avatar
Chances are the only differences between the .40 and .45 is the crankshaft and/or piston/liner.

Get ready - they’re screamers. Don’t forget the speeders mantra. RPM RPM RPM!!!!!!!!!!!
Feb 24, 2020, 06:41 AM
Registered User
I had the 7.5 for a few years but sold it when someone offered me more than I could turn down.
Feb 24, 2020, 10:00 AM
GloBroz PowerLab
1QwkSport2.5r's Avatar
I wouldn’t mind finding a 3.5cc DF/Marine engine sometime. I have a boat that needs more oomf than the OS 21 SE-M can muster.
Feb 24, 2020, 10:32 AM
Scott
Pylonracr's Avatar
Quote:
Originally Posted by 1QwkSport2.5r
I wouldn’t mind finding a 3.5cc DF/Marine engine sometime. I have a boat that needs more oomf than the OS 21 SE-M can muster.
Tim, I have your 3.5 marine engine. Never run. Send me a PM.

Scott
Feb 24, 2020, 02:18 PM
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A few months ago, I ran my K&B 3.5CC FIRE Aero on a test stand, it just loved to rev with a regular muffler, I was worried the prop blades may depart!
Feb 24, 2020, 02:56 PM
GloBroz PowerLab
1QwkSport2.5r's Avatar
Quote:
Originally Posted by Sam Ehab
A few months ago, I ran my K&B 3.5CC FIRE Aero on a test stand, it just loved to rev with a regular muffler, I was worried the prop blades may depart!
My buddy has one of those engines - we broke it in on the bench one day with a short pipe. Holy cow!! It staged the pipe at 22k and was full on the pipe at around. 26-27k. There was no in between - it was either 22,000 or 26,000+.
Feb 24, 2020, 03:38 PM
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Thread OP
I can't remember if mine had a Perry pump or not, I may be confusing it with my K&B 7.5CC motor, but my 3.5CC is not a DF engine, just a regular one with that funky cross muffler with dual exhaust outlets.
Feb 24, 2020, 04:29 PM
Scott
Pylonracr's Avatar
Quote:
Originally Posted by Sam Ehab
I can't remember if mine had a Perry pump or not, I may be confusing it with my K&B 7.5CC motor, but my 3.5CC is not a DF engine, just a regular one with that funky cross muffler with dual exhaust outlets.
The marine engine I have has that muffler, exhaust throttle, and a venturi.

Scott
Feb 24, 2020, 05:12 PM
GloBroz PowerLab
1QwkSport2.5r's Avatar
Quote:
Originally Posted by Pylonracr
The marine engine I have has that muffler, exhaust throttle, and a venturi.

Scott
My buddy’s 3.5 engine came with that dual outlet muffler too. It would have run like crap on that muffler with how the engine is timed. It definitely liked the short pipe we had on my buddy’s.

Hey Scott. I sent you a PM.. where’s my reply?

Jackass™️
Feb 24, 2020, 05:34 PM
Scott
Pylonracr's Avatar
Quote:
Originally Posted by 1QwkSport2.5r
My buddy’s 3.5 engine came with that dual outlet muffler too. It would have run like crap on that muffler with how the engine is timed. It definitely liked the short pipe we had on my buddy’s.

Hey Scott. I sent you a PM.. where’s my reply?

Jackass™️
Oh, I answered your PM....
Jackass

Scott
Feb 24, 2020, 06:21 PM
GloBroz PowerLab
1QwkSport2.5r's Avatar
Quote:
Originally Posted by Pylonracr
Oh, I answered your PM....
Jackass

Scott
Took ya long enough.
Feb 24, 2020, 07:43 PM
Registered User
Thread OP
I had to use this auto oil filter removal tool to get the stuck sleeve of the case.


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