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Athena big bore kit

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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.

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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..

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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?

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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..

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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.

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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.

IMGP1297.jpg

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

IMGP1294.jpg

Left Side

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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.

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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 :bonk: UK either :smirk::lol::banana::lol:

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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.

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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.)

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

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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.

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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?

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.)

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