Athena

[Chango]

Anyone have an Athena bigbore on thier 450R ?Iam looking for a little more bottom end but like the top end pull of my hrc cam.I am a desert racer and just wondering if anyone has tried this combo yet ..GOOD? BAD? Is welcome..

[WhiteZee]

you can safely run a 480cc 14:1 piston in the stock jug, i woud go with that.

[Got nads?]

I have the Athena 480 kit, and can verify that it has more bottem, and topend power. I am trying a 15 tooth front sprocket right now, and I still have lots of bottem end power. I do only have a 1 hour ride on my current setup though so it is hard to tell. The advantage I guess is I can still run premium pump gas!

[predatorkick@$$]

I have ran the athena 480 for 6 months and have loved it!!

[Chango]

I want it but i would like to run a 15 36 or 15 37 and pull it in the sand washes.what kind of compression are you all running 13 ,12,11.5????i don't have a problem running race fuel i run it any ways at least mixed 5050

[Chango]

real pic

[predatorkick@$$]

The athena comes with a 10:5 If i remeber correct which work great!! I am looking for a 14:1 or 13:5 for mine know but everwhere is sold out of them!!

[WhiteZee]

i dont understand why someone would buy an aftermarket cylinder for something that has been proven to work perfectly fine in the stocker.

[predatorkick@$$]

I did it so I would have a back up stock cylinder and the athena has bigger water jackets with little more wall thickness than stock bored out!!

[Chango]

same here i want the stock backup cylinder and the price for the athena is not bad for all you get

[predatorkick@$$]

Are you sure is 12:1 when I called them when researching it the said piston was 10:5!!

[Got nads?]

I am pretty sure it was 12:1, but I think I threw out the info that came with the kit. I will ask my mechanic the next time I talk to him.

[predatorkick@$$]

I still have all my info but does not say on it! I rember when I put together and did not look different then stocker exept bigger around and nothing like the 13:1 I took out!!

[mike nash]

I just seen a dyno chart showing 40.5hp w/10.7 comp. And stock being 38.5 . Is it woth spending 700.00 for 2.0 hp? Or woulld higher comp like 12.1 be more worth while.

[WhiteZee]

i still say its retarded to buy this kit, just bore and plate your stock cylinder, its proven to be reliaible

[Got nads?]

It is not always about peak horespower, I noticed a hugh diference in throttle response. If I jump off my buddies 2005 450R that has a sparks pipe, 05 crf cam, & other mods, my quad pulls harder even when it is geared up. This is just my opinion though. The only reason I went with the 480 is for ice racing and my sponser gave me a really good deal. Oh yeah, and because my crank bearings went so I had to rebuild my motor anyways!

[Chango]

Originally posted by WhiteZee
i still say its retarded to buy this kit, just bore and plate your stock cylinder, its proven to be reliaible Ok add up the cost of using your own cylinder gaskets hi comp piston+cc bore couple mm sleeve re nikil seal and no spare parts....Then the athena then whats seems to make more sense

[WhiteZee]

if you want to use sissy compression.

[Chango]

I' ve never heard of sissy compression,Is that what you have ?and how does it work?I see you crunched numbers and the athena makes alot of sense.When you ride hard for several hundred mile at a time 14.1 compression is not your best friend try running Pemex in that

[SLIDING]

While I was over in the USA, myself and a friend brought Athena 480 kits for our trxs. We both also brought HRC kits. I also brought a K&N + billet adaptor and a Alba exhaust and header pipe. My friend all ready had a pro circuit rear muffler.

We installed the Hrc kits. I also installed my exhaust and air filter. We rode them like this for about 4 weeks (Dunes,MX Track,woods,Speedway). They did of course go heaps better!!

I do have access to my old dyno (hassle). But Im 40 now, so Im not looking to win any more major races. So seat of the pants dyno info only!

My bike was about two bike lengths faster than my friends in a roll on from 2nd to the rev limiter in 5th with a 13 tooth front on both. I weigh about 20 kgs more than him.

Mine had more mid to top end. His had more low down. This is mainly due to the differant types of the exhaust. (slip on vs stepped header big bore muffler)

We then fitted the Athena kits. I machined 27 thou off both heads. Mildly ported the heads. Doing most of the work on unshrouding the valves now that the bore size was not such a limiting factor. As well as a nice 5 angle valve job.

The compresion ratio ended up at 12.2.1. Intake piston to valve clearance was 83 thou. The exhaust didnt touch the plastascene (more than a 100 thou).

Was impressed with the quality of the kit. No Significant oil burning. The bikes now have way more power EVERYWHERE. The peak of the torque curve is now lower down in the rpm range. The hrc cam comes in sooner and just starts to fall very very slightly at the standard rev limit. We ended up with 180 main jets.

Our bikes are alot quicker ( 2.5 bike lengths ahead till there rev limit advantage kicks in) than YFZ450s which have been piped,jetted,no lid and retimed exhaust cam.

I paid $550 from DT dyno for kit.

Thought you might want to know.

[400exrider707]

Originally posted by SLIDING
While I was over in the USA, myself and a friend brought Athena 480 kits for our trxs. We both also brought HRC kits. I also brought a K&N + billet adaptor and a Alba exhaust and header pipe. My friend all ready had a pro circuit rear muffler.

We installed the Hrc kits. I also installed my exhaust and air filter. We rode them like this for about 4 weeks (Dunes,MX Track,woods,Speedway). They did of course go heaps better!!

I do have access to my old dyno (hassle). But Im 40 now, so Im not looking to win any more major races. So seat of the pants dyno info only!

My bike was about two bike lengths faster than my friends in a roll on from 2nd to the rev limiter in 5th with a 13 tooth front on both. I weigh about 20 kgs more than him.

Mine had more mid to top end. His had more low down. This is mainly due to the differant types of the exhaust. (slip on vs stepped header big bore muffler)

We then fitted the Athena kits. I machined 27 thou off both heads. Mildly ported the heads. Doing most of the work on unshrouding the valves now that the bore size was not such a limiting factor. As well as a nice 5 angle valve job.

The compresion ratio ended up at 12.2.1. Intake piston to valve clearance was 83 thou. The exhaust didnt touch the plastascene (more than a 100 thou).

Was impressed with the quality of the kit. No Significant oil burning. The bikes now have way more power EVERYWHERE. The peak of the torque curve is now lower down in the rpm range. The hrc cam comes in sooner and just starts to fall very very slightly at the standard rev limit. We ended up with 180 main jets.

Our bikes are alot quicker ( 2.5 bike lengths ahead till there rev limit advantage kicks in) than YFZ450s which have been piped,jetted,no lid and retimed exhaust cam.

I paid $550 from DT dyno for kit.

Thought you might want to know.



Did the cam chain tensioner take up all of the slack in the chain from you shaving the head? Wouldn't that throw the timing off some?