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have a couple of questions.......i have a 06 trx 450 with +3hot rods crank, athena big bore kit. my questions are head work, cam, and comp. should i go with +1 intake and exhaust or just exhaust? i have a hot cam stage 3, and web "mysto" cam. which one would be better? i've heard alot off good about the hot cam, but unsure on the web. as far as compression, should i use the athena piston or bump it up some? cuz im thinking the athena piston is around stock comp. but i could be wrong!

my brother has a 05 yfz w/hot rods +3 crank, athena big bore kit, and +1 intake and exhaust valves. my questions on this is the compression and cams. should he go with higher comp? and he also has a set of hot cams and web 943 (i think, its the step up from the +5) again i heard you cant beat the hot cams!!

both yfz and trx carbs have been bored out, and have dyna ign. and is set up for motorcross! also, would it be benificial to lighten the fly wheels on either one?

thank you for your time, and ANY imfo is better than NONE!!!!
 

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i think who ever ports your head , would need to recommend the valve size etc, some builders do +1s all around and some do differently,

with the trx i think a stage2 cam would be agood choice for ur riding, good power and tq , there is better top end monsters though,

yfz im clueless on..lol

and i hear with the athena pistons they are heavy and lower comp 11.1-12.1???? so id probally change that but thats me

on ur 05 trx FCR carb would probally be a good investment for the throttle response with MXing
 

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I have no clue on the YFZ...

but on the 06 TRX.. get rid of the Dyna ignition....yes, I said it.......

2nd...if your wanting a MX setup..... forget the HCIII...and go with either the 06 HRC cam (04-06 CRF cam).....or..possibly the HCII......

3rd....the MORE compression...the better...... that Athena piston is only about 11.4:1..... lower than stock....... if your racing MX... get a Venom 14:1.....if your talking about the 100mm Athena big bore kit...... this is a strong combination...... +3mm crank... +4mm bore..... 511CC is a runner for sure...... the above parts will keep her reliable..and healthy....

jmho...me~
 

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Discussion Starter #4
I have no clue on the YFZ...

but on the 06 TRX.. get rid of the Dyna ignition....yes, I said it.......

2nd...if your wanting a MX setup..... forget the HCIII...and go with either the 06 HRC cam (04-06 CRF cam).....or..possibly the HCII......

3rd....the MORE compression...the better...... that Athena piston is only about 11.4:1..... lower than stock....... if your racing MX... get a Venom 14:1.....if your talking about the 100mm Athena big bore kit...... this is a strong combination...... +3mm crank... +4mm bore..... 511CC is a runner for sure...... the above parts will keep her reliable..and healthy....

jmho...me~[/b]

well what ignition do you use? and yes i'm talking about the 100mm kit. i know i would have to re-time it but, what if i had the head milled down to make up the difference? thanks for your replies too!!!
 

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you can safely mill the head .020" or so.....this will give ya some more compression...... the Athena Jug is not a high quality piece.... not in my opinion.... and their gaskets that come with their kits are even worse.........there are several high quality piston companies.... CP, JE, Wiseco....etc... Venom custom pistons are made by CP.... and are designed rather well, plus, they actually have them in 100mm HIGH comp..... so it is a good choice and very reliable.....

as for the ignition... there is NO aftermarket CDI that is more reliable...or even AS reliable... as stock... there have been numerous issues associated with aftermarket ignitions.....

the stock CDI is perfect.... use an HRC sub-harness or 'green wire mod' and she is good to go.... this will program your CDI to higher rpms, and a better timing curve.....

jmho......me~
 

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Discussion Starter #6
you can safely mill the head .020" or so.....this will give ya some more compression...... the Athena Jug is not a high quality piece.... not in my opinion.... and their gaskets that come with their kits are even worse.........there are several high quality piston companies.... CP, JE, Wiseco....etc... Venom custom pistons are made by CP.... and are designed rather well, plus, they actually have them in 100mm HIGH comp..... so it is a good choice and very reliable.....

as for the ignition... there is NO aftermarket CDI that is more reliable...or even AS reliable... as stock... there have been numerous issues associated with aftermarket ignitions.....

the stock CDI is perfect.... use an HRC sub-harness or 'green wire mod' and she is good to go.... this will program your CDI to higher rpms, and a better timing curve.....

jmho......me~[/b]

whats not good about the athena? i can see what your talking about on the cdi, it ran really good with the stock one and i tried the dyna and it seemed to have no bottom or mid(compared to the stock cdi) but about the same on top with a higher rev limit. just curious, what is jmho.......me~ ? and thanks for the imfo!
 

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you can safely mill the head .020" or so.....this will give ya some more compression...... the Athena Jug is not a high quality piece.... not in my opinion.... and their gaskets that come with their kits are even worse.........there are several high quality piston companies.... CP, JE, Wiseco....etc... Venom custom pistons are made by CP.... and are designed rather well, plus, they actually have them in 100mm HIGH comp..... so it is a good choice and very reliable.....

as for the ignition... there is NO aftermarket CDI that is more reliable...or even AS reliable... as stock... there have been numerous issues associated with aftermarket ignitions.....

the stock CDI is perfect.... use an HRC sub-harness or 'green wire mod' and she is good to go.... this will program your CDI to higher rpms, and a better timing curve.....

jmho......me~[/b]

whats not good about the athena? i can see what your talking about on the cdi, it ran really good with the stock one and i tried the dyna and it seemed to have no bottom or mid(compared to the stock cdi) but about the same on top with a higher rev limit. just curious, what is jmho.......me~ ? and thanks for the imfo!
[/b]

oops....I used the wrong wording....not JUG....but SLUG.... the piston... the cylinder is great.... purdy darn strong...and very nice, almost perfect, nikasil plated cylinder.......... but their piston doesnt appeal to me at all.....first off... two low of compression... second.... the ones I have seen..and I still have a brand new one sitting on my shelf...... has casting flaws in it.... appears to be CAST...not FORGED..... not sure what Athena claims...... it is light...... as light as any other quality piston.... but I would not trust it with Nitrous.....and if I wont trust it with nitrous...why trust it w/o.....? get the best....... this of course can be debated....between several top brand companies....and ill keep my opinion out of this......but I dont think too many high HP machines are running the stock athena piston..... jmho

the CDI is self explanatory as you noticed.... aftermarket = worse power..and less reliability..... stock CDI with green wire mod or sub harness is the way to go.......
 

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replace the dyna with the green wire mod.

id bump up the compression with a cp piston.

whos doing your headwork?
have them inspect your head and see if you need oversize valves.
 

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Discussion Starter #10
can i get any more opinions?? going to tear em down and rebuild! thanks guys
 

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have a couple of questions.......i have a 06 trx 450 with +3hot rods crank, athena big bore kit. my questions are head work, cam, and comp. should i go with +1 intake and exhaust or just exhaust? i have a hot cam stage 3, and web "mysto" cam. which one would be better? i've heard alot off good about the hot cam, but unsure on the web. as far as compression, should i use the athena piston or bump it up some? cuz im thinking the athena piston is around stock comp. but i could be wrong!

my brother has a 05 yfz w/hot rods +3 crank, athena big bore kit, and +1 intake and exhaust valves. my questions on this is the compression and cams. should he go with higher comp? and he also has a set of hot cams and web 943 (i think, its the step up from the +5) again i heard you cant beat the hot cams!!

both yfz and trx carbs have been bored out, and have dyna ign. and is set up for motorcross! also, would it be benificial to lighten the fly wheels on either one?

thank you for your time, and ANY imfo is better than NONE!!!![/b]
id like to try that mysto cam.....or see some runs from it..
 

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have a couple of questions.......i have a 06 trx 450 with +3hot rods crank, athena big bore kit. my questions are head work, cam, and comp. should i go with +1 intake and exhaust or just exhaust? i have a hot cam stage 3, and web "mysto" cam. which one would be better? i've heard alot off good about the hot cam, but unsure on the web. as far as compression, should i use the athena piston or bump it up some? cuz im thinking the athena piston is around stock comp. but i could be wrong!

my brother has a 05 yfz w/hot rods +3 crank, athena big bore kit, and +1 intake and exhaust valves. my questions on this is the compression and cams. should he go with higher comp? and he also has a set of hot cams and web 943 (i think, its the step up from the +5) again i heard you cant beat the hot cams!!

both yfz and trx carbs have been bored out, and have dyna ign. and is set up for motorcross! also, would it be benificial to lighten the fly wheels on either one?

thank you for your time, and ANY imfo is better than NONE!!!![/b]
id like to try that mysto cam.....or see some runs from it..
[/b]
Id like to see some comparison graphs of a mysto too. I used to think it was a crazy amazing cam that only ran good in beast builds now im hearing its poo compared to like a 208 etc.
 

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it is really an elusive cam for numbers... steve "zips" tried one and I believe he lost power to an hrc or HC2 or something in a big build.... Tice got one and said the lobe centers were way off compared to the specs... then i bought the mysto cam from Zips and ended up selling it because i chickened out before trying it.. it could be a great cam, just not that good of a dyno queen cam... there is one for sale in the parts section for 100 bucks right now...
 

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Discussion Starter #15
i did try this cam before i went to the dyno and it didn't run no better than the 208! about the same until top end which i thought the 208 pulled harder on top. the 208 compared to the stage three was about the same in a drag race but i felt it had a little more mid to get me over some jumps on my track! hope this helps anyone out. i dont think its as good as you would think for a "race only" cam!!!
 
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