gx390

IM looking for all or any mods for a gx390.

Hello everyone.I need some advice.Iv got a new HF 13HP 390 clone in the box.I want to hop it up a bit but still keep the pull-start if I can?,,so I know there are limits. 20HP would be nice but maybe Im dreaming,,,what parts do I need to buy to make this a Strong fast fun engine? I would...

The robertson gx390 header comes with a set of allen key screws that secure the header to the block.The old threaded screws wount come out of the block i tried heating them up nothing.I am going to weld the nut to the end of the thread than back it out with a 13mm scoket.Is that a good idea or...

I want to advance the timming on my gx390 but i dont have a tool to measure how much to shave does anybody sell the keys in advance or can estimate the amount to shave.Thanks

I have a GX390 mildly modified Header,uni filter jetted carb governor removed ,billet rod and a flat top piston.Im lookind for a good clutch i have a clutch thats rated for up to 10 hp,And im guess im pushing 15 or 16 hp.The clutch I have slips bad and get red hot quick.What im getting at does...

let me know if you have one, i broke the adjustment screw on mine and need a carb asap

I was trying to tune my 11Hp 340 yesterday and i broke the adjustment screw tip off the adjuster.. the carb was a gx390cc carb and im trying to figure out how change it, the screw comes with a square stopper allowing about a half turn of adustment, no that the stoper is there i dont know what to...

I'll be moving on very quickly to round 3 of my biofuel powered Mini Baja/ Yerf Dog buildup. The chassis is appropriately sized for my big ass. Now that the DOT tire issues are taken care of and I don't have to modify the frame, I can jump right into the motor swap. I want to swap the motor for...

My Gx390 DragMini first runs, GX390 has a carb, header, billet rod and flywheel. All else is Stock. Cam and springs wouldnt allow it to run past the 1/8th mile. New head, cam and carb being added this week.... Me On it YouTube - JD Making a few Passes on the Drag Mini Baby Making a...

I'm in the market for a GX200, GX340 or a GX390 for my DB30. I Don't care how used it is, or if it's knocking or whatever, I'm a mechanic. Would prefer that it has the necessary mods for the throttle linkage, clutch if possible would be nice as well. Would prefer to pay through pay pal...

Looking for a GX390 Cam let me know what you got?

I'm fairly new to small engines. I'm looking to upgrade my carb for a Clone 6.5 which is on a custom mini chopper frame. Which is better Mikuni or GX390? What are the advantages and disadvantages between the two. What would be the cheapest price range for either setup. Thanks for your...

I was just wondering what the size of the crank journal and stroke was, Thanks in advance. Rick

Updated Jammer Tomahawk 4 disc 1" bore.

GX200 Clone and GX390

GX200 Clone and GX390

GX200 Clone and GX390

GX200 Clone and GX390

GX200 Clone and GX390

What kind of rpm's can the GX390 turn with the stock valve springs and no governor? I was using this to get a rough idea of top speeds: http://www.minimotogarage.com/ecm_speed_calc.html