cams or big bore?

[Z28patches]

okay so 2005 kfx400 with 13:5:1 comp piston i did myself and i just need more grunt for racing..
dont got a ton of money but what would you guys go with
i want both one day but just for now
HELP

[knoxville9]

Well if you do a big bore before cams most say that its not worth it. So from what ive heard i'd do cams first

[cataway]

i was getting 40hp on a stock bore get,cams , carb, better intake and P&P

[wona go fast]

cams! u will get near nothing with just a biger bore, all the power is in the head!

but i hope u have other mods if ur doing cams/ aftermarket filter and exhuast jet that kinda stuff

[Z28patches]

yeah i got full yoshi pipe jet kit but i got a edelbrock carb sittin waitin but i think that was a waste of cash
programable CDI box
K&N lid and filter and of course the 13:5:1 wiseco piston
but WebCams the best i seen well atleast this one dude at the race last week
he said to have it Bored 416, webcams installed and headwork done by Baldwin and was straight killing 450 660 700 and even this 1550 v-twin harley that was put on a atv frame

webcams or hotcams?

[cataway]

Originally posted by Z28patches


webcams or hotcams? depends on how much money you have to spend

[airmobile101]

IMO, I would go with Web Cams if you have that engine built to the hilt!

[killer400ex]

deffinetly go with hotcams, if your compression is that high then go with a stage two, hot cams seemed to give me a bit more of a push off the line and snappier responce, not to mention the top end power

[cataway]

stage 2 , whats that ?

[jonboy]

Haha!

Why are you waiting on the Eddy carb? There are alot of folks who love them due to the ease of tuning. IMO the FRC is better but a royal PITA to get dialed in. You've got the 13.5:1 already?Go ahead and get the cams. Make the bike breath better first. If you go with a BBK with out breathing you're rolling on a ticking time bomb. Definately get a port job done. While you have the head off go ahead and get the DRZ valve springs and timing chain. You'll thank yourself later, especially with that much compression. Start putting back to build it right the first time instead of tearing into it to upgrade or repair so much. Personally 12.5:1 is the limit I would put on the Z motor just for reliability and longitivity reasons.

[airmobile101]

Originally posted by jonboy
Haha!

Why are you waiting on the Eddy carb? There are alot of folks who love them due to the ease of tuning. IMO the FRC is better but a royal PITA to get dialed in. You've got the 13.5:1 already?Go ahead and get the cams. Make the bike breath better first. If you go with a BBK with out breathing you're rolling on a ticking time bomb. Definately get a port job done. While you have the head off go ahead and get the DRZ valve springs and timing chain. You'll thank yourself later, especially with that much compression. Start putting back to build it right the first time instead of tearing into it to upgrade or repair so much. Personally 12.5:1 is the limit I would put on the Z motor just for reliability and longitivity reasons.
I agree with most of that except the port and polish. The z400 head flows pretty damn good being stock compared to a Honda 450r. I would definately do the cam chain and springs. I would say the valves,but I have yet to personally meet someone that floated a stock valve,but like jonboy said,you have it apart,you might as well do it right the first time.

[jonboy]

The reason I recomend the P&P is due to the high comp. and cams together will require more undisturbed intake volume and it will definately need to exhale it as much as possible. He already has the best head pipe available for this on the Yosh system. He will be repacking alot with that kind of pressure. The intake side would need work also such as using a 400ex intake boot or like cataway is working with the DS650 tube but there are others out there like the ESR, Velocity, or the FCI for the yfz450. Im sure there are others too.

[airmobile101]

Originally posted by jonboy
The reason I recomend the P&P is due to the high comp. and cams together will require more undisturbed intake volume and it will definately need to exhale it as much as possible. He already has the best head pipe available for this on the Yosh system. He will be repacking alot with that kind of pressure. The intake side would need work also such as using a 400ex intake boot or like cataway is working with the DS650 tube but there are others out there like the ESR, Velocity, or the FCI for the yfz450. Im sure there are others too.
Ill say a exhaust port only,but I will pretty much agree with yea. But as Yoshi being the best head pipe, no way!!! All the head pipes are damn near identical besides the FMF megabomb. The head pipe boils down to your taste.IMO

[cataway]

Originally posted by jonboy
The reason I recommend the P&P is due to the high comp. and cams together will require more undisturbed intake volume and it will definitely need to exhale it as much as possible. He already has the best head pipe available for this on the Yosh system. He will be repacking alot with that kind of pressure. The intake side would need work also such as using a 400ex intake boot or like cataway is working with the DS650 tube but there are others out there like the ESR, Velocity, or the FCI for the yfz450. I'm sure there are others too.

if i may just qualify some thing about the ds 650 boot ,it wont
work for every one ,there is an adapter that is needed on the fcr to make it fit ,which i highly recommend being put on the fcr .
it will fit to the 04-05 trx450r carb but not to many guys using that carb.
the adaptor is an easy fit but will requaire some work to get a perfict fit ,
both noss and venom offer the adapter .

[airmobile101]

Originally posted by cataway
if i may just qualify some thing about the ds 650 boot ,it wont
work for every one ,there is an adapter that is needed on the fcr to make it fit ,which i highly recommend being put on the fcr .
it will fit to the 04-05 trx450r carb but not to many guys using that carb.
the adaptor is an easy fit but will requaire some work to get a perfict fit ,
both noss and venom offer the adapter .
Would I need to add a Ratstack for that?

[cataway]

to a fcr from a yfz ,yes