Athena big bore kit

Started by jviz1, Nov 24 2011 11:35 PM
17 replies to this topic

  • jviz1

Posted 24 November 2011 - 11:35 PM

#1


Just got a Athena Big Bore kit from ebay, and the cylinder doesn't look right. The gasket mating surfaces are not machined, almost look casting rough. There is also a sleeve pressed into cylinder.

Also, 'Athena' is NOT stamped into the side of the cylinder. Can someone visually check thier Athena big bore cylinder, and validate that 'Athena' is stamped into it.
Thanks.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed

  • highmarker

Posted 25 November 2011 - 03:02 PM

#2

got one in box here somewhere,,,,,,,,,, I'll try and find it

  • jviz1

Posted 26 November 2011 - 06:57 AM

#3

If you do find it, look at the head gasket surface. Is it machined, or does it have a rough sand finish, similar to the sand casting finish on the sides?

Also, does it have steel sleeve?

During the installation, i had gotten to the point of adding water, and little droplets of water started seeping out between head and cylinder. Pulled it apart, and now questioning the quality of the kit..

  • highmarker

Posted 26 November 2011 - 07:19 AM

#4

the cyl base suface does have a cast texture (not machine lines), it has "athena" cast into both sides as you see them on the bike (cheaters might grind them off), looks to use a nicisil plated alum sleeve, the water jackets are bigger than oem and bulge out a little more



water? like the head gasket didn't seal?

  • jviz1

Posted 26 November 2011 - 09:34 AM

#5

Thanks.
My cylinder does not have Athena cast into either side.

Yes, it was leaking, as if the head casket did not seal. That's why I started looking at the surface of cylinder, and whether it should be machined smooth.
The Athena head gasket seems ok. The 3 layer thick, with a rubberized coating..
I have thought of trying a copper coat, but will wait till I get feedback from sellor.

The sellor is contacting Athena..

  • highmarker

Posted 26 November 2011 - 05:47 PM

#6

there is 2 locating dowel sleeves from the cyl to the head, is it possible they didn't get installed?

  • jviz1

Posted 26 November 2011 - 08:16 PM

#7

Dowels were in.
Have read of similar water leaks with yz250f Athena 290 kit, and the solution there was to use cometic gaskets. Cometic big bore gaskets not available for crf.

  • Riprocken

Posted 21 December 2011 - 08:56 AM

#8

I'd guess you got a knock off. Heres a few pics from my installed kit purchased from Motosport last year. The stamps are quite clear.

If you have a knock off, good luck getting it to seal. I would see if the vendor will take it back. Considering it is not what they said they sold you. You could at least file an ebay complaint. Ebay sucks for new parts,, you never know what you are really going to get. The only parts I ever buy on ebay are used from private sellers with lots of pics of the actual part. Even then you can still get ripped off. Purchase new from a reputable vendor and avoid this kinda stuff all together.

Posted Image
Right Side,,, never mind my wasted exhust rap.

Posted Image
Left Side

  • Riprocken

Posted 21 December 2011 - 09:00 AM

#9

jviz1 said:

Thanks.
My cylinder does not have Athena cast into either side.

Yes, it was leaking, as if the head casket did not seal. That's why I started looking at the surface of cylinder, and whether it should be machined smooth.
The Athena head gasket seems ok. The 3 layer thick, with a rubberized coating..
I have thought of trying a copper coat, but will wait till I get feedback from sellor.

The sellor is contacting Athena..

Sounds like they are stringin you out. Don't be surprised when the seller account disapears before they reply.

You should contact Athena, I am pretty sure all their stuff is stamped. They will be able to tell you for sure if you have a knock off. If it is real they will stand behind it no matter where you bought it.

  • GoonSquadCRFx

Posted 21 December 2011 - 12:44 PM

#10

Looks like you got ripped off my friend. Remember you bought it on Ebay. Did it come from China and was it $100? A great deal is usually to good to be true.... Those are always a red flag:smirk:

PS: I heard not to order from the :aussy: UK either :lol::lol::lol::lol:

  • jviz1

Posted 11 February 2012 - 05:06 PM

#11

Ended up getting a replacement cylinder from Athena, which took weeks.
Did use copper spray on head gasket to ensure a good seal.
Anyways, it's running good, hoping it's reliable.

  • stroker

Posted 13 February 2012 - 09:27 AM

#12

Has anyone tried the Cylinder works 270 kit? it is supposed to keep the top end over rev better and less compression braking than the Athena, and cheaper.

Just saw a write up in Dirt rider magazine, sounds like cylinder works kit added power with out some of the things I did not like about athena 280 kit I tried in my 2008 CRF250 (Athena had more power but also had more compression braking, less over rev.)

  • Riprocken

Posted 15 February 2012 - 09:33 AM

#13

I ran a stg2 hot cams with my Athena,, top end was incredable.

  • Riprocken

Posted 15 February 2012 - 10:02 AM

#14

And its easy to over come the engine braking,,, stop letting off the gas.

  • kenhawg

Posted 16 February 2012 - 07:39 PM

#15

+1 on the Athena 280 and the stage 2 Hotcam. Bike has tons of bottom and pulls forever.

  • hm450

Posted 03 March 2012 - 07:45 AM

#16

Next time, try Vertex....

  • YHGEORGE

Posted 05 March 2012 - 01:01 PM

#17

View PostRiprocken, on 15 February 2012 - 09:33 AM, said:

I ran a stg2 hot cams with my Athena,, top end was incredable.
Sounds like you are happy with the bike setup. Do you HS or Enduro? Would you go this(X) route again or BB the MX model for the same use? Thanks.

  • highmarker

Posted 05 March 2012 - 06:14 PM

#18

The CW 270 will not drop on the X or early R's without grinding away a little of the case, same with the vortex 290/300. The 10+ r motor the mag tested has more clearnece and starts out with a smaller bore stock, so adding a little bit more bore ends up with a lighter piston (compared with the earlier motor). This is, (im guessing) part of the reason why they noted it seemed to rev better than earlier bb kits they tried?




View Poststroker, on 13 February 2012 - 09:27 AM, said:

Has anyone tried the Cylinder works 270 kit? it is supposed to keep the top end over rev better and less compression braking than the Athena, and cheaper.

Just saw a write up in Dirt rider magazine, sounds like cylinder works kit added power with out some of the things I did not like about athena 280 kit I tried in my 2008 CRF250 (Athena had more power but also had more compression braking, less over rev.)



  1. ThumperTalk
  2. → Dirt Bike
  3. → Make / Model Specific
  4. → Honda
  5. → CRF250X
If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!