PC motor, is the juice worth the squeeze?

bangmyhead
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bangmyhead
Edited Date/Time 11/28/2012 4:45pm
Just wondering if PC motors are worth the money in upkeep (PC Valves hi comp JE piston) as opposed to a stocker with a pipe and remap?

Also any input on the cooper seats would be great
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therealjonon
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therealjonon 11/28/2012 8:56am
11/28/2012 8:56am
id say yes i grew up riding for mitch all the years i raced BUT.... what about the new motors factory connection are pushing...they seem to be just as fast.
bangmyhead
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bangmyhead 11/28/2012 9:03am
11/28/2012 9:03am
i have a built motor from PC and a stock motor for my '11 kx250f. Both engines have about 40hrs on them (rebuild time soon). I know with the PC motor since it has the cams i'll need to run pc valves but hot damn they are a pretty penny. just trying to get some input on which one to rebuild and which one to sell
slipdog
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slipdog 11/28/2012 9:13am
11/28/2012 9:13am Edited Date/Time 11/28/2012 9:14am
bangmyhead wrote:
i have a built motor from PC and a stock motor for my '11 kx250f. Both engines have about 40hrs on them (rebuild time soon). I...
i have a built motor from PC and a stock motor for my '11 kx250f. Both engines have about 40hrs on them (rebuild time soon). I know with the PC motor since it has the cams i'll need to run pc valves but hot damn they are a pretty penny. just trying to get some input on which one to rebuild and which one to sell
You don't have to run their valves with their cams, stock Ti valves will work just fine. If you want a upgraded valve anyway, Del West valves(they make the valves for PC) are the same and cost much less. The copper seats are softer and less abrasive than stocks seats so they are better for longevity. They also Dissipate heat better from the valves.
bangmyhead
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bangmyhead 11/28/2012 9:34am
11/28/2012 9:34am
slipdog wrote:
You don't have to run their valves with their cams, stock Ti valves will work just fine. If you want a upgraded valve anyway, Del West...
You don't have to run their valves with their cams, stock Ti valves will work just fine. If you want a upgraded valve anyway, Del West valves(they make the valves for PC) are the same and cost much less. The copper seats are softer and less abrasive than stocks seats so they are better for longevity. They also Dissipate heat better from the valves.
With the del west valves can you run stock springs or do they make the spings for PC too?

Ive heard that you can potentially, or have a higher chance of floating a valve if you run OEM valves with the PC cams?

Thanks for the input Cool

The Shop

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gsxr6
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gsxr6 11/28/2012 9:44am
11/28/2012 9:44am Edited Date/Time 11/28/2012 9:46am
slipdog wrote:
You don't have to run their valves with their cams, stock Ti valves will work just fine. If you want a upgraded valve anyway, Del West...
You don't have to run their valves with their cams, stock Ti valves will work just fine. If you want a upgraded valve anyway, Del West valves(they make the valves for PC) are the same and cost much less. The copper seats are softer and less abrasive than stocks seats so they are better for longevity. They also Dissipate heat better from the valves.
The seats are probably the best part of the package longevity wise. I have always wondered why the non pro guys dont run leaded fuel to help with valve wear. i know a guy who only ran leaded in a kx450 and had over 200 hours on his valves. 3 pistons and he only had to adjust the valves once
gsxr6
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gsxr6 11/28/2012 9:45am
11/28/2012 9:45am
dude was 250 lbs and he wasnt slow or easy on that bike
slipdog
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slipdog 11/28/2012 9:57am
11/28/2012 9:57am
bangmyhead wrote:
With the del west valves can you run stock springs or do they make the spings for PC too? Ive heard that you can potentially, or...
With the del west valves can you run stock springs or do they make the spings for PC too?

Ive heard that you can potentially, or have a higher chance of floating a valve if you run OEM valves with the PC cams?

Thanks for the input Cool
The spring you run is related to the cam profile not the valve. Unless you switch to heaver SS valves there's no real weight difference between stock, PC/Del West or Xceldyne Ti valves. Cam profiles with more lift or duration changes that increase lift speeds will usually require more valve control than stock springs can handle.

So you can use any aftermarket Ti valve in your stock motor and still use stock springs, but if you run aftermarket cams you may need to upgrade the spring kit.
slipdog
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slipdog 11/28/2012 10:06am
11/28/2012 10:06am
gsxr6 wrote:
The seats are probably the best part of the package longevity wise. I have always wondered why the non pro guys dont run leaded fuel to...
The seats are probably the best part of the package longevity wise. I have always wondered why the non pro guys dont run leaded fuel to help with valve wear. i know a guy who only ran leaded in a kx450 and had over 200 hours on his valves. 3 pistons and he only had to adjust the valves once
The biggest problem with the 4-stroke engines IMO is the lack of understanding the average consumer has about the way they work and how to maintain them. People that understand even the basics tend to have very little problems, but most people don't even learn to check the their valve clearances.
bangmyhead
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bangmyhead 11/28/2012 10:19am
11/28/2012 10:19am
slipdog wrote:
The spring you run is related to the cam profile not the valve. Unless you switch to heaver SS valves there's no real weight difference between...
The spring you run is related to the cam profile not the valve. Unless you switch to heaver SS valves there's no real weight difference between stock, PC/Del West or Xceldyne Ti valves. Cam profiles with more lift or duration changes that increase lift speeds will usually require more valve control than stock springs can handle.

So you can use any aftermarket Ti valve in your stock motor and still use stock springs, but if you run aftermarket cams you may need to upgrade the spring kit.
Sounds like i'll have to bite the bullet on just the PC spring kit, or if you could recommend a cheaper alternative (kinda like Del west or JE), again i appreciate you shedding light on this for me.
slipdog
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slipdog 11/28/2012 10:36am
11/28/2012 10:36am
bangmyhead wrote:
Sounds like i'll have to bite the bullet on just the PC spring kit, or if you could recommend a cheaper alternative (kinda like Del west...
Sounds like i'll have to bite the bullet on just the PC spring kit, or if you could recommend a cheaper alternative (kinda like Del west or JE), again i appreciate you shedding light on this for me.
Unless you are having it built by a professional motor builder, I'd go with the PC spring kit. In many cases they are over kill which can cost you some power, but better safe than sorry. With the cam, piston and valves you still will have a net hp gain over stock and wont have a time bomb on your hands. Mitch is smart like that, he knows do-it-yourselfers can't calculate things like seat pressure, nose pressure or install heights.
Craze
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Craze 11/28/2012 10:41am
11/28/2012 10:41am Edited Date/Time 11/28/2012 10:41am
therealjonon wrote:
id say yes i grew up riding for mitch all the years i raced BUT.... what about the new motors factory connection are pushing...they seem to...
id say yes i grew up riding for mitch all the years i raced BUT.... what about the new motors factory connection are pushing...they seem to be just as fast.
They should be...they"re PC motors
Awhit167
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Awhit167 11/28/2012 11:54am
11/28/2012 11:54am
Craze wrote:
They should be...they"re PC motors
No FC honda motors are from yoshimura
dilligaf
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dilligaf 11/28/2012 2:23pm
11/28/2012 2:23pm
Craze wrote:
They should be...they"re PC motors
Awhit167 wrote:
No FC honda motors are from yoshimura
FCR motors are done in-house by a very select crew. They run Yosh exhaust systems but motors are done in house.

Many people also think Yosh does Rockstar Suzuki motors... nope they are in=house as well.
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Denn700 11/28/2012 2:37pm
11/28/2012 2:37pm
My PC 250f is way faster than stock and last about the same hours. I would put the PC valves in because they have been race tested. You also have to run the PC high PSI radiator cap. I made that mistake first and coolant would literally spray out of the hoses when the bike was started.
motoarmageddon 11/28/2012 2:52pm
11/28/2012 2:52pm
i doubt if either PC or FC sells engine work that is like their pro team engines. I rode a PC CRF250 with like $4000 in mods to the engine alone and i wasnt impressed with the power at all. it felt like it revved a little tighter than stock, but overall power was not a lot more.
bangmyhead
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bangmyhead 11/28/2012 2:57pm
11/28/2012 2:57pm
Denn700 wrote:
My PC 250f is way faster than stock and last about the same hours. I would put the PC valves in because they have been race...
My PC 250f is way faster than stock and last about the same hours. I would put the PC valves in because they have been race tested. You also have to run the PC high PSI radiator cap. I made that mistake first and coolant would literally spray out of the hoses when the bike was started.
1.6 cap?
activeMX
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activeMX 11/28/2012 3:00pm
11/28/2012 3:00pm
Slipdog hit the nail on the head with his comments on 4-stroke tuning and maintenance. What your buying from Pro Circuit is "customer cut" though......aside from those pricey Beryllium Copper seats and Ti valves.

I can recommend a better valve spring kit IMO for your bike than what PC has to offer (I engineered it) but nothing in it for me anymore so put your money towards PC. Re-cut the seats, run stock valves, MegaCy.....errrrr Pro Circuit cam, springs and piston is a solid enough motor.
bangmyhead
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bangmyhead 11/28/2012 3:28pm
11/28/2012 3:28pm
activeMX wrote:
Slipdog hit the nail on the head with his comments on 4-stroke tuning and maintenance. What your buying from Pro Circuit is "customer cut" though......aside from...
Slipdog hit the nail on the head with his comments on 4-stroke tuning and maintenance. What your buying from Pro Circuit is "customer cut" though......aside from those pricey Beryllium Copper seats and Ti valves.

I can recommend a better valve spring kit IMO for your bike than what PC has to offer (I engineered it) but nothing in it for me anymore so put your money towards PC. Re-cut the seats, run stock valves, MegaCy.....errrrr Pro Circuit cam, springs and piston is a solid enough motor.
the motor has already been built by pro circuit, already has the cams piston valves seats ect. Im just trying to get a grasp on what this motor is going to cost me/what is needed to run a motor like this. for example i had no idea about the radiator cap. I knew JE pistons are in theory PC pistons without the logo as Del West Valves are PC valves without the label.

ive always kept my 4 strokes stock as i have a keystone light budget Wink but dont let the keystone light budget fool you to think i dont change pistons at 30hrs check valves every 15 ect.

Im not racing to make a living so its not like i need a race motor but at the same time if i got one and its only gonna be a few extra bucks to rebuild compared to the stock i might as well rock the PC engine

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motokiwi 11/28/2012 3:31pm
11/28/2012 3:31pm Edited Date/Time 11/28/2012 3:32pm
Why dont you just run a stock 450 instead of a mod 250? You will save a ton of $ and have just as much fun.
Or even better still if you want MAX fun, just get a 250t Wink
bangmyhead
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bangmyhead 11/28/2012 3:35pm
11/28/2012 3:35pm
motokiwi wrote:
Why dont you just run a stock 450 instead of a mod 250? You will save a ton of $ and have just as much fun...
Why dont you just run a stock 450 instead of a mod 250? You will save a ton of $ and have just as much fun.
Or even better still if you want MAX fun, just get a 250t Wink
got ya covered, just finished my 144 Wink

jhansen510
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jhansen510 11/28/2012 3:48pm
11/28/2012 3:48pm
Jonon, you better be repping Mitch with all the support he put your way coming up! If I could of had just one of those badass bikes that you had back then I could die a happy man! Bangmyhead, what bar bend is on that KX144?
bangmyhead
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bangmyhead 11/28/2012 3:51pm
11/28/2012 3:51pm
jhansen510 wrote:
Jonon, you better be repping Mitch with all the support he put your way coming up! If I could of had just one of those badass...
Jonon, you better be repping Mitch with all the support he put your way coming up! If I could of had just one of those badass bikes that you had back then I could die a happy man! Bangmyhead, what bar bend is on that KX144?
996
Falcon
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Falcon 11/28/2012 4:10pm
11/28/2012 4:10pm
You guys who want to make your valves last longer should take a page out of the 2-stroke handbook and run premix. Don't go crazy with it or anything - I'm talking about 100:1 or maybe even 125:1. Your top end doesn't need the oil, but it acts as a cushion on the valves. I also believe it creates a better valve seal, but that's just speculation on my part. The factories were experimenting with this in 2005-2006-2007. Not sure if they run premix now or not.
Braaap14
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Braaap14 11/28/2012 4:24pm
11/28/2012 4:24pm
went with yosh. couldn't be happier. mitch isn't winning championships for no reason, but you're not getting the motor and the touch he puts on his race bikes, you're getting service dept work.
jhansen510
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jhansen510 11/28/2012 4:41pm
11/28/2012 4:41pm
Im going to agree ith Braaap14! For the consumer I think Yoshi or 11/10 gives the most bang for the buck. Mitches shit for his guys is top notch. For the average Joe, I have heard some pretty bad horror stories on the service depts end....
flomiester
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flomiester 11/28/2012 4:45pm
11/28/2012 4:45pm
i have been working on a new kx spring kit the retainers are made from ti 17 a higher grade of titanium there also being coated with tian so they dont wear the springs are pac racing.The work with my agressive cams .400" lift Theres a lot of new things coming from RHC.

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