CR Machine Stage 2 high performance engines

crmachineman

crmachineman

New Member
Hi everybody.
I don't always have one in stock, so here is a heads up!
You will be amazed at the power this engine can make!
Maximum power is achieved when a good expansion chamber style exhaust is used.
I found really good results using the RT race carb. (dellorto clone). I'm sure a lot of you guys are familiar with this carb.
DAX sells them for a excellent price, and they come with a nice range of jets. The RT flat slide carb. seems to provide perfect mixture for all engine speeds.
Soon I should have some of these carbs. to go with the engines on my ebay store.
Due to the high torque of this engine, you will probably want to get a small rear sprocket.
My test bike uses a 30 tooth sprocket driving a 26 inch rear tire.
If you want to check out this engine, here's the ebay link:
http://www.ebay.com/itm/Motorized-b...Parts_Accessories&vxp=mtr&hash=item1e72727495
Hope you like it!
And please let me hear your comments!
-Fred
.shft.
 

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They look amazing and surely have much more power. I think the price is ok too but personally for that money I would rather get a KTM50 with 9HP and 13.000rpm. If the price would have been around 220-250 I would have ordered one last week because mine had a stuck piston.
 
Hi.
Yeah, that is the very best price I can manage. I've been looking at that engine DAX carries. One thing that comes to mind with that engine... How about replacement parts? If you need a new piston, or a clutch, where do you go to get one? If somebody knows, I would like to know. That KTM50 engine seems like one I would like to explore myself. The cylinder head seems to not have all that much cooling capacity, so 9 HP may only be achievable for short durations.
Now, the engine I'm making has adequate cooling capacity for constant full output because of the special cylinder head. And this engine, with the special intake plenum has a HUGE powerband. It starts from idle speeds and pulls hard all the way up to maybe 8000 RPM (it's a educated guess). This is perfect for single speed bikes.
Slow ride:
I don't have a dyno, so I can't tell you what the horsepower is. What I can tell you is that on my test bike I can exceed 50 MPH on the straight. I actually tested this engine with a stock exhaust and was able to reach the same speed top speed, however mid range torque was markedly less than when I was running a nice expansion chamber style exhaust.
My single speed test bike is running a 30 tooth sprocket driving a 26 inch wheel, and even with such a small rear sprocket, the bottom end torque is amazing! I never imagined that this kind of engine could run this well. If I didn't mind slipping the clutch a little, it could start up from a complete stop!

Anyway, thanks for the comments!
-Fred
.trk
 
JonnyR said:
the KTMs are expensive at that point i would rather buy a loncin or lifan 150cc with the 4 speed manual
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i found the KTM50 with Carb for about $360.-. I think thats an ok price if you compare the quality with the China crap

But I dont want to make advertisement here for other engines because I think CR does a great job.
 
the loncin and lifan are 110-150cc engines for about the same price not as usefull to most of us but what i would use since they are almost 12hp with a transmission.also they are 4 stroke and have race parts that are fairly cheap.
 
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BarnstormCyclewerks said:
is it possible to send a motor to serve as a core exchange for a reduced price?
Click to expand...

Hi.
Well, I suppose there would be some savings. I would reuse the clutch parts, except put new clutch pads in. I would reuse the case halves and the hardware.
If the hardware is damaged, I would say it's not worth it, just keep it around in case you need to cannibalize it for parts yourself. If the core is good, I'd say you would end up saving about $30.00
Thanks
-Fred
 
Thanks! Right now I'm really eyeballing your head/cylinder to referb an old engine i have lying around. Regarding the complete engine, do you happen to do any balancing to the crankshaft, or have found that fixing any misaligned/distorted cranks tends to reduce the vibrations?
 
Hi Will,
That is a good question.
The straightening and truing of the flywheels does help reduce vibrations by essentially bringing the crank back to original design specifications. Of course it solves the automatic hand grenade problem the distorted cranks have, due to the hurried Chinese workers who force the engine halves together. I do not change any of the original balancing work. My experiences with running the CR Machine engines is that they run nice and smooth, until you get into the upper RPMs, like over 7,000 RPM. I believe it is nearly impossible to balance a single cylinder engine like this to run smoothly at all RPM's. Taking this into account, I have focused my engines to perform well at low RPM, giving adequate low speed torque to allow you to select a small rear wheel sprocket, allowing you to achieve good top speeds, without being forced to rev the **** out of the engine.
Thanks for your support!
-Fred
 
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