Gt5A-ES ENGINE Don Butler Custom Modified

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

The engine can be Pedal Started as well as OCDT Electric Drill Start.   Heads up! 

We now have OCDT in stock, order the CCW version right side engine start.

The improvements Don makes are not obvious from the outside.  When we get your order, we send Mr. Butler one of our SkyHawk Gt5A-ES engines and that  takes about 2 days by Priority Mail. 


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 less than 1mm.   

6.  Checks clutch operation and adjust accordingly. 

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

8.  Removes the OCDT flap over the OCDT hole.   Guess he wants to give lonely Mud Dobers a home place.      We can ask him to reinstall the flap if you want.   

9.  If you order an CCW OCDT along with the engine we can include it with the engine we send Mr. Butler. 

10.  We will send him a 7 pcs Shim kit and CDI Module to be include with his masterpiece engine.   At the rear he includes 2 long nuts to better hold engine to the bike's down tube. 

11. He ships the engine via USPS Priority Mail insured.  He spends a whole day making the engine into a sweet running China Doll just 4U.   

12. Bear in mind that Mr. Don Butler has a backlog of customers waiting to get their engines fine-tuned.   If you are in a hurry best email me first to see his delivery quote before ordering.  Please understand, once ordered no refund.