Gt5A-ES ENGINE Don Butler Custom Modified

Grubee Inc


Heads up! This CUSTOM MODIFIED engine can be Pedal Started as well as OCDT Electric Drill Started.   

Here's a standard Gt5a-ES SkyHawk 66cc engine that has been given the Golden Midas touch by the world-famous Don Butler Speed Shop in Chickasha OK.   

This engine has a Don Butler balanced 10-hole crank along with exhaust port and transfer ports timing corrections to enable super RPM performance that Don's Speed shop is famous for.  

Included is our OCDT with CCW cranking rotation for right side Hex M6 engine starting using 1/2" Cordless drill.

Please know the improvements Don makes are not obvious from the outside. 

We send Mr. Butler one of our SkyHawk Gt5A-ES engines ahead of time to ensure that we always have one to sell immediately with next day shipping.  

 1.  When received, Don disassembles our engine and balances and aligns the crank assembly.  ( 5 balance holes instead of the stock 2.)  

2.  He Protractor indexes the piston travel to TDC and BDC and then Dremel grinds the cylinder transfer ports and exhaust ports to gain maximum engine efficiency.   

3.  Reinstalls and shim realigns the crankshaft.    Replaces any bearings not to spec. 

4.  Checks piston to cylinder slide fit. 

5.  Secures a piston squish of 1mm or slightly less.   

6.  Checks clutch operation and adjust accordingly. 

7.  Installs his God-awful decal on the magneto cover.  

9.  We include a 7 pcs Shim kit and a HP CDI Module to be include with his masterpiece engine.   

10.  Butler spends a whole day making the engine into a sweet running 66CC China Doll just 4U.   

12. Bear in mind that Mr. Don Butler has a backlog of customers waiting to get their engines fine-tuned.   So, if you are in a hurry, we have one on the shelf ready to go for immediate next day insured USPS Priority shipping.    

Please understand, once ordered no refund but does carry engine run warranty out of the box.