KX144 big bore kits?

kxf993

PR Member
Im thinking about making my KX 125 a 144. Just curious if anyone else has done one before and what the best way to go about doing it myself would be.
 
I recommend Eric Gorr at Forward Motion. He is the best at big bore 2 strokes. We have a kx 134 that flat rips.
 
I recommend Eric Gorr at Forward Motion. He is the best at big bore 2 strokes. We have a kx 134 that flat rips.

I have a Gorr big bore kit.....I wouldnt trust him to feed my dog let alone my bike ever again!

Poor workmanship and horrid customer service. My bike hasnt run right since he did the motor. I ended up going back to a stock 125 to fix it!
 
I have used Eric Gorr in the past on my kx 100 just port and polish and it didn't run right when I got it back either, it kept blowing the head gasket and I finally realized the mating surface on the top of the cylinder was nicked. I don't know if it was his fault or not. Has any one ever bought the Athena kits and done it themselves?
 
The one piece head kits are great, just stay away from the 2 piece heads. They warp and blow head gaskets.
 
I have an 04 RM 144 that Eric Gorr did. Once I figured out the jetting it runs great and has been very reliable. I put 10 hours on it between piston and rings and they always look great. Could probably go 12-15 hours. Service is a little slow but always accurate.
 
I have an 04 RM 144 that Eric Gorr did. Once I figured out the jetting it runs great and has been very reliable. I put 10 hours on it between piston and rings and they always look great. Could probably go 12-15 hours. Service is a little slow but always accurate.

His service is great until you have a problem, then it goes in the toilet. Search the web about him. I wish I would have first, TONS of unhappy customers.
 
His service is great until you have a problem, then it goes in the toilet. Search the web about him. I wish I would have first, TONS of unhappy customers.

That's a tough one. I mean you can't realistically expect him to have done a thourough R&D test on every bike he offers work for...can you? Gorr knows 2-stroke and can mod you a cylinder that will work well. As far as jetting, etc., well, Gorr can give you ideas on what to do, but every situation is different in terms of other mods, etc. Also thinking he assumes and/or expects his customers to know more than they might which relates to gaps in communication.

My KX300 isn't quite right, but runs awesome for the most part and I'll get there. I think I will be very happy once I do. I am now, but just a few things I am still trying to figure out to get it "factory" right. If I had the YZ250 he did R&D on, I'll bet he could tell me right now what to do with it...

As far as searching the web, that's a failing case. Search the web about God and Jesus to see if they have unhappy customers....
 
He built a motor for me and the same one for another person on here. Runs for garbage and its NOT jetting on both. Ive tried every jetting combo there is. He told me it was an air leak. BS. I tore the motor down 3 times, no air leaks. 2 years of not riding a bike I paid $1100 to mod sucks. It loves to break off the tip of spark plugs even when the jetting is goopy rich. One time it cost me $600 to repair everything and he told me it was my fault. Eff him. His workman ship is terrible as well. My motor was low hour factory new when it went to him and returned with leaking pv seal and 3 stripped bolt heads. One bolt was a used rusty replacement.

I would be ashamed if I were him. He basically told me to bad.
 
Im thinking about making my KX 125 a 144. Just curious if anyone else has done one before and what the best way to go about doing it myself would be.

Its all about airflow, bigger isn't always better. Head mods, polished exhaust port, V-Force reed and matched cases is you best, most reliable option. PM me if you want some good people to call.
 
talonrunner-i just installed new v force reeds and also have pro circuit platinum pipe and R304 silencer. I havnt got to ride it with the vforce installed yet because of a broken back. I'm not 100% sure i wanna do the 144 kit yet just looking for ideas. As far as Gorr goes, i have only had him build one of my bikes and i had poor results as i said earlier. But i dont think it was his fault. i think i sent him an already messed up cylinder, but you would think he would have seen it and given me a heads up?
 
Depending on what year you have... Athena makes a kit for the 03 and up. I am about to do one and here is the list of accomplices... Cylinder, cylinder head, and power valve will go to U.S. Chrome. U.S. Chrome will do the bore and plate and Finish Line Engines (I think trained by Eric Gorr) will do the port work, head, and power valve. Athena will handle the piston assembly, gaskets, I will match the cases to the cylinder and take care of jetting.

U.S. Chrome offers great discounts for AMA racers. I am an Athena sponsored rider, so it looks like I can get the whole job done for about $400.
 
step one- remove cylinder
step two- send to millenium technologies
step three- pay for a replate and big bore piston
step four- reassemble and ride with smiles!
 
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