New 21 CMB Beta

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Just got done running my new Beta for the first time and after 10 tanks of fuel it's showing some promise. Didn't lean on the motor too much and got some good rpm out of it. The only thing I did to the engine was cut the low speed off cause it was hitting the throttle linkage. I ran the CMB nitro pipe at 8 inches and had a little trouble pulling a H5 prop if I didn't let the engine get hot before launch. Will update after more testing.
 
huh? what kind of rigger? My NR's would pull just about anything off the beach.. center ski style though.. I could launch H7's from just about a dead stop,..
 
My new Beta in a JAE pulls one of Marks H-7 with no problem. CMB nitro pipe@ 8" and 55%. Couldn't do much testing since we had 20-30MPH gusts of wind at our lake. All my runs were mainly trying to avoid blowing over from the wind but when I was able to run WO things looked promising. My next runs will be with all the head shims removed.
 
anthony_marquart said:
huh? what kind of rigger? My NR's would pull just about anything off the beach.. center ski style though.. I could launch H7's from just about a dead stop,..
Click to expand...
I'm running a hummingbird. Ski boats pull H7's easy. I actually pulled my H7 that I run in my JAE today but the boat wouldn't get back up after mill. My boat is setup for rough race water so I don't run big props. I prefer to be able to hold it wide open when others can't due to loose setups. Don't get me wrong the boat is running 65 to 70 all day. After race season I'm going to put the motor in the JAE and see what it can do but it really is a great motor. CMB definitely did there homework on this one.
 
It really doesn't matter if you can pull a H7 or only 1445! Big props don't mean your gonna go fast!!

At end comes down to pitch Vs Rpm's!

Each to there own!

Let us know how your testing goes!

Regards Aaron
 
Sgx 21 1445, small props big props. Just takes work to make them go. Any engine is capable.

 
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aaron alberico said:
It really doesn't matter if you can pull a H7 or only 1445! Big props don't mean your gonna go fast!!

At end comes down to pitch Vs Rpm's!

Each to there own!

Let us know how your testing goes!

Regards Aaron
Click to expand...
Yup! Our Old SG ran constantly 74 mph with a 1445. Engine was a 1997 Novarossi. Pipe was Irwin S pipe as short as we could get it. Was a consistent race boat. John has many 1st place trophies to prove it.
 
Tim, I am unsure of the prop numbers, Andy sent me a sharpened and balanced prop and I bent it till it hauled the mail.
 
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Im not being critical... I ran a pitched up 1445 on my JAE style boat it was as fast as any prop.. it just blow out more easily than a larger diameter prop, on my boat. If I ever get this floor done,.. I'll actually get my last boat running..

I feel the fall coming soon.... my favorite time to run boats..
 
Beta Update,

We had three Beta 21 motor racing this past weekend. Two were in "B" hydros and one in a "B" Mono. David and I are still working with props, fuel setting and pipe length but the motors are showing get potential. David and Oily placed on the podium. I messed up in milling time on the final round and the boat never cleared out I was in second until then.

CMB got this motor right. I'm pulling at least one prop size larger on my Black Jack hydro with not launch issues and have only take out 2 plugs in the first gallon of fuel.

Bert Dygert
 
My motor is broke in enough where I can start playing with the pipe lengths however I had good rpm over the weekend with an H5 at 8 inches. It still sticks at the top but can be turned over with the propeller. I've run about a gallon and a half of fuel through it.
 
David Murany said:
My motor is broke in enough where I can start playing with the pipe lengths however I had good rpm over the weekend with an H5 at 8 inches. It still sticks at the top but can be turned over with the propeller. I've run about a gallon and a half of fuel through it.
Click to expand...
Cut the water down, open up the needle and let it eat!
default_tongue.png
 
Terry Keeley said:
David Murany said:
My motor is broke in enough where I can start playing with the pipe lengths however I had good rpm over the weekend with an H5 at 8 inches. It still sticks at the top but can be turned over with the propeller. I've run about a gallon and a half of fuel through it.
Click to expand...
Cut the water down, open up the needle and let it eat!
default_tongue.png
Click to expand...
That's already done. I'm running the motor 20 points richer on our Boris meter than any other 21 engine Ive ever ran.
 
Heh Dave:

I have a Boris dont know if its gen3 or gen4 and never really used it before, but when I put the Blackjack on it I was at 78, while my old Speedmaster meter was at 70. . Maybe I will bring it to Spencer and flow it on your meter to get a baseline number. I know it was really rich at the Nats. Tony J

David Murany said:
timothy johnson said:
David what are your Borris #s, is it a new model flow meter!!
Click to expand...
It's a Gen 4. I'm running the motor at 112 with a Bob violet 3rd channel needle. The water is cut down to 120 on the same meter.
Click to expand...
 
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Ran my JAE Beta several times over the weekend . I ran the engine at .009, 8'' CMB nitro pipe, 55% , OD Blue plugs and a Shouland H-7. The engine is still getting broke in but is running much better than my VAC motor. I ran the engine at .112 for fuel flow and water at 120. I did burn a few plugs with a coil pulled out so if any one is having better performance with another plug please post your info. Thanks to everyone for posting their comments Tm
 

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