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Is real powerband improvement possible?

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I am in a bit of a quandary with my trusty 02 CR250.

 

I am getting to a point where I'm really pushing the engine pretty hard especially in loose/loamy conditions to get drive. The powerband on the bike is really all or nothing, and really even when its really on, its not doing what a 250 2T should do. I am beginning to understand why these engines were disliked by the magazine testers. Here's a list of engine mods on the bike:

 

04 cylinder (I know this was supposed to be worse than the 02, but I really didn't notice much difference one way or another)

05 base gasket

Keihin 38 pwk

PC platinum pipe/r304 silencer

Rekluse clutch

 

Anyway, I'm beginning to get tired of struggling to keep up with the 4t's. My bike is just very squirrelly and its really hard to keep a smooth line in anything but the most tacky conditions. I want to race something that is competitive in the 250c and vet classes, and I just don't think my bike is cutting it.

 

I am not in good enough shape and my skill level isn't close to where it needs to be for me to really ride my bike like it demands. I'll be honest what I really am wanting is a bike with a better spread of power.

 

So here are the options that I am currently considering:

 

1. Go to a 4t (I know this won't be popular here but I am considering it)

2. Get some port work done, maybe go to a big bore kit (kind of would be cheating in the 250 class but hell I ain't going to be winning races any time soon so I don't think it'll be a big deal)

3. Jump ship to KTM or Yamaha 2t's which have far superior engines from the get-go

 

Any other options you guys might suggest here? I really like my bike and I want to keep holding the 2T banner up, but man I don't want to keep chasing my tail and holding myself back. I ain't getting any younger here.

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For an 02 I'd recommend a fly wheel weight (9oz) but since you hot a rekluse im not sure if that added weight or not, not familiar with rekluses. ditch the PC pipe for a OEM pipe in good shape or FmF fatty, (PC silencer is good though) also would do an Eric gorr mo better port job to spread the power out. Lastly, jetting plays a big part in how these Cr's run but it sounds like you got that covered with the pWK.

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Yes, it's possible to achieve a real powerband improvement.   I've posted as well as other members in order to realize the potential of this motor some form of mods needs to be done.   The case reed motor was an unfinished project by Honda due to the R&D work going to the CRF450r, CRF250r &  the devolopment of  the CRF X models.   The motor can dramatically improve depending on how much work your willing to have done.  There are different ways to achieve the results your looking for, but EG seems to be the popular choice.

I went thru this back in 03-05 racing against the 450's & started feeling at a disadvantage at the line.  My fittness would get me towards the front at the end of the moto, but was lacking the starts & having to work harder.  In my case I sent out a 03 cyl / head & had PC perform their port work & head cut for race gas.  The end result was a wide & very strong useable powerband that feels like my 93 motor on steroids.

If your willing to put some time & work in thew motor it will reward you.   It's my favorite 250t motor after some mods...            

Edited by H4L

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Yes, it's possible to achieve a real powerband improvement.   I've posted as well as other members in order to realize the potential of this motor some form of mods needs to be done.   The case reed motor was an unfinished project by Honda due to the R&D work going to the CRF450r, CRF250r &  the devolopment of  the CRF X models.   The motor can dramatically improve depending on how much work your willing to have done.  There are different ways to achieve the results your looking for, but EG seems to be the popular choice.

I went thru this back in 03-05 racing against the 450's & started feeling at a disadvantage at the line.  My fittness would get me towards the front at the end of the moto, but was lacking the starts & having to work harder.  In my case I sent out a 03 cyl / head & had PC perform their port work & head cut for race gas.  The end result was a wide & very strong useable powerband that feels like my 93 motor on steroids.

If your willing to put some time & work in thew motor it will reward you.   It's my favorite 250t motor after some mods...            

 

I guess I'm just apprehensive about dropping a grand or more into the motor and taking a chance that I still won't like it is all. I have some thinking to do I suppose.

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I guess I'm just apprehensive about dropping a grand or more into the motor and taking a chance that I still won't like it is all. I have some thinking to do I suppose.

Where did you get $1K from ?   My PC mods cost me $350 & I believe EG has better pricing for his engine modifications. 

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Where did you get $1K from ?   My PC mods cost me $350 & I believe EG has better pricing for his engine modifications. 

Ehh...just being conservative. By the time I factor in a new piston/gaskets and also rebuilding the crank etc the money could add up quickly.

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I just sent my 06 motor to Eric Gorr today.  I was quoted $100 to have him cut .030 off the base of the cylinder and cut the head for pump gas.  would be the same price to cut the head for race gas.  I was quoted $225 to have the cylinder base cut by .030 have the head cut for pump/race gas and get a full porting package which would include raising and widening the exhaust ports, epoxy in the ports for better air flow and cleaning up casting flaws in the ports.  EG has 3 different porting packages you can choose from, I chose his "mo betta" porting for the broadest smoothest power delivery.  I think that is very reasonable for what he does to the motor.

Edited by frdbtr

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I just sent my 05 motor to Eric Gorr today.  I was quoted $100 to have him cut .030 off the base of the cylinder and cut the head for pump gas.  would be the same price to cut the head for race gas.  I was quoted $225 to have the cylinder base cut by .030 have the head cut for pump/race gas and get a full porting package which would include raising and widening the exhaust ports, epoxy in the ports for better air flow and cleaning up casting flaws in the ports.  EG has 3 different porting packages you can choose from, I chose his "mo betta" porting for the broadest smoothest power delivery.  I think that is very reasonable for what he does to the motor.

 

Cool...could you pm me or report here what kind of a difference you feel when you get it running again?

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Cool...could you pm me or report here what kind of a difference you feel when you get it running again?

 

I plan on it ;)  My default thread for my 06 is called "should I trade" since it started with me considering trading my 450 for an 05 250.

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Is your suspension dialed in for you? I know your complaint is about the motor and the power spread, but without first having your suspension set up all that power will be useless. It also won't tire you out as quickly and will get the power to the ground. If you do decide to do engine work I think porting or even the big bore kit as you mentioned will make a difference for you. The big bore kit comes with porting and all the top end components as well and would obviously make the biggest difference.

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For an 02 I'd recommend a fly wheel weight (9oz) but since you hot a rekluse im not sure if that added weight or not, not familiar with rekluses. ditch the PC pipe for a OEM pipe in good shape or FmF fatty, (PC silencer is good though) also would do an Eric gorr mo better port job to spread the power out. Lastly, jetting plays a big part in how these Cr's run but it sounds like you got that covered with the pWK.

 

IMO, the PC pipe is an excellent choice for MX so I would keep that.

 

Anyway, I'm beginning to get tired of struggling to keep up with the 4t's. My bike is just very squirrelly and its really hard to keep a smooth line in anything but the most tacky conditions. I want to race something that is competitive in the 250c and vet classes, and I just don't think my bike is cutting it.

 

A 450F is a lot of fun on any terrain. If you setup the suspension that would help but the 450 gets better traction most everywhere. 

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the cr250 is a diamond in the rough.

 

Do some motor work and it will come alive,

 

on the cheap

 

  • 2005+ base gasket, its thinner and lowers the cylinder altering the port timing, improving the dead spot in the lower rpm
  • send head to rbdesigns for ,040 squish and domed for pump fuel, more power easier jetting wayy less spooge
  • send stock carb to rbdesigns, dicks racing etc for carb mods.
  • jd jetting
  • rc vavle mod (google it) it helps the power valve close fully for better lowend power

OR spend a few $ and use this list

  • send it eg or kenoconnorracing for cylinder base cutting and head mods, possibly porting or 265 big bore
  • pwk 38mm carb off 2000 cr250 or shorty lectron smart carb
  • still do rc valve mod

 

I had a 2002 cr250, love how it handled the motor was a pooch tho, no power no power than all the power at once in a burst than no power again. Back then I just got a 05 m250 and built a race fuel only motor for it (scary)

IF you do the simple things I have listed it will come alive.

Edited by adam8781

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the cr250 is a diamond in the rough.

Do some motor work and it will come alive,

on the cheap

  • 2005+ base gasket, its thinner and lowers the cylinder altering the port timing, improving the dead spot in the lower rpm
  • send head to rbdesigns for ,040 squish and domed for pump fuel, more power easier jetting wayy less spooge
  • send stock carb to rbdesigns, dicks racing etc for carb mods.
  • jd jetting
  • rc vavle mod (google it) it helps the power valve close fully for better lowend power
OR spend a few $ and use this list
  • send it eg or kenoconnorracing for cylinder base cutting and head mods, possibly porting or 265 big bore
  • pwk 38mm carb off 2000 cr250 or shorty lectron smart carb
  • still do rc valve mod

I had a 2002 cr250, love how it handled the motor was a pooch tho, no power no power than all the power at once in a burst than no power again. Back then I just got a 05 m250 and built a race fuel only motor for it (scary)

IF you do the simple things I have listed it will come alive.

Like he said, doesn't take a lot to wake it up, head & carb mods go a long way with these motors, but sadly with any engine how fast it is is directly proportunate to the amount of money you put into it haha

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I have a PC modded 02 the runs VP C12 and I love it! Ton's of power. I came off a 2005 YZ450F before the CR

 

http://www.thumpertalk.com/topic/823571-pro-circuit-porting-and-head-mods-for-02-04-cr250s-review/

 

Read your review...sounds nice and fast but not necessarily easier to ride. I'm looking for something that is easier, not harder to ride. I don't want to have to be in the crazy part of the powerband all the time hanging on for dear life. I want more power, yes, but I also want it to be more manageable. Would you say your bike is easier to ride effectively after the PC mods?

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the cr250 is a diamond in the rough.

 

Do some motor work and it will come alive,

 

on the cheap

 

  • 2005+ base gasket, its thinner and lowers the cylinder altering the port timing, improving the dead spot in the lower rpm
  • send head to rbdesigns for ,040 squish and domed for pump fuel, more power easier jetting wayy less spooge
  • send stock carb to rbdesigns, dicks racing etc for carb mods.
  • jd jetting
  • rc vavle mod (google it) it helps the power valve close fully for better lowend power

OR spend a few $ and use this list

  • send it eg or kenoconnorracing for cylinder base cutting and head mods, possibly porting or 265 big bore
  • pwk 38mm carb off 2000 cr250 or shorty lectron smart carb
  • still do rc valve mod

 

I had a 2002 cr250, love how it handled the motor was a pooch tho, no power no power than all the power at once in a burst than no power again. Back then I just got a 05 m250 and built a race fuel only motor for it (scary)

IF you do the simple things I have listed it will come alive.

 

I have the pwk and base gasket but like you say I probably need to send the cyinder and head off to a specialist for mods.

Edited by MrN2OBelvedere

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Also, how much do I stand to lose if I have the engine ported for pump gas? I mean $10 a gallon for gas is a bit steep.

Not a lot, any porting is improvement, and sure race gas will make it crazy, but like you said you want it controllable and getting it built for pump fuel will probably do just that

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I've ridden an 05 & 07 with mods done to run with pump fuel.   Also had my 1st 03 motor done by a local tuner to run on pump gas & the engines had noticeably smoother manageable powerbands.  After working & tuning these motors for the last 10 years I've learned they respond really well to port work & head mods.  It just depends on what type of power & powerband your looking for.

  

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