Athena yz 144

I have an 05 yz 144 for Eric Gorr and I have a 06' yz 144 with the athena kit.

Eric's Kit is cheaper by about $ 250.00. You will have to send Eric your entire motor. He will also port the cylinder to how you want it. Mine is ported for a strong low to mid power.
That being said I did have some issue with the kit initially,,, (Eric took care of them) I also had a broken exhaust port bridge later on.

The Athena kit seems to be very well made. Revs like hell but lacks bottom end you may or may not desire. Race feul is a must. It also runs abit cooler withless vibration than my E.G. kit (which I also run race feul).

I would prob lean towards the Athena kit myself, but I ordered a top end two months ago and it is still on back-order.
They say maybe mid Nov. so if you have sudden problem you maybe S.O.L. Eric was able to get me a piston within 2 days for his kit.

Build your stock cylinder to 144

Depends on what you are looking for.

Eric will custom port it for you. Want low end, or want a rocket he'll make it work. He can also get parts to you quick. My top end was built to run on pump gas, however it did detonate like hell at high rpm and after virtually blasting the crown off of the piston I switched to race fuel and the problem was solved.

Looking for a kit that screems up top, the Athena is great. You will still have your stock cyclinder and valves to fall back on. You will have to grind your cases to allow for the proper clearance you cannot just bolt the kit on.

Athena review.

I have the Athena kit on my 2005 YZ and also had the Gorr mods done to my stock engine. Both work great. I bought the Athena kit because after running the Gorr 144 for a while I sent it back for a little head work and porting. I installed the modified parts and found that the top end power was amazing but I lost all the low end power. I incorrectly assumed it was the porting, so I instaled the Athena 144 kit. I found while installing the Athena kit that the power valve was not installed properly at the engine end and was stuck open resulting in the lack of bottom end.

Both motors run great and would be competitive with 250 four strokes. More importantly is that the bike is so much fun to ride. I find that I can usually pull a higher gear over the same sections of the track when compared to the stock motor. I would reccommend either one.

Mod Edit - This part belongs in the For Sale forum only