06 CR 250, can't get any top end, help!?!

[mxrcr4]

Hey guys, I have had my 06 CR 250 since August. It has a great mid-range but no top end. It seems to hit pretty hard in the middle then just signs off and won't carry the gear through to the top, kind of falls flat. I have done the following so far;

JD jet kit (huge help and now jetted perfect)
V-Force 3 reeds
FMF SST pipe
FMF Shorty silencer
Power Valve cable adjusted

What would you suggest I do next? I really like a mid to top end power curve in a two stroke, I don't mind it hitting hard, but it has got to have some top end overrev. Straights I used to hold my 05 KX 250 open in 3rd, I am now out of power half way down them and having to shift to 4th on my CR, probably shifting twice as much around the whole track.

 

[oldfrt613]

Are you sure your jetted OK on the main jet. Have you checked the power valve cables ? Sounds like the power valve is not opening up all the way. Double check the timing next. My '05 rips on top. Mine is ported, but it ran good stock on top end with the mods you mentioned. I have also seen mixed reviews on the SST pipe. I prefer the Factory Fatty or PC pipe - short silencer on mine.

 

[mxrcr4]

Yes, I adjusted the power valve cables per the instructions and links from this site. I think it is right!?! Not positive though, but I will check. The jetting is good all around. It has been like this since new, just not too much top. I am kind of leaning towards sending it to Eric Gorr for porting and maybe changing the pipe if he recommends it.

 

[DLHamblin]

Hey guys, I have had my 06 CR 250 since August. It has a great mid-range but no top end. It seems to hit pretty hard in the middle then just signs off and won't carry the gear through to the top, kind of falls flat. I have done the following so far;

JD jet kit (huge help and now jetted perfect)
V-Force 3 reeds
FMF SST pipe
FMF Shorty silencer
Power Valve cable adjusted

What would you suggest I do next? I really like a mid to top end power curve in a two stroke, I don't mind it hitting hard, but it has got to have some top end overrev. Straights I used to hold my 05 KX 250 open in 3rd, I am now out of power half way down them and having to shift to 4th on my CR, probably shifting twice as much around the whole track.

From the tests I read; the '06 CR250 was basically all top-end? How was the top end before the mods/jetting? Perhaps something is working against something else killing the top end?

Did you do the mods one step at a time or all at once?

 

[oldfrt613]

Yes, I adjusted the power valve cables per the instructions and links from this site. I think it is right!?!

Quick check on the cable - there should be no perceptable play in the cables. Try dropping the main jet 1 size - see if it runs any cleaner on top. If your willing to spend the money to get her ported, that's always good. You just may have a cylinder with the port timing off, it is just a casting, while Honda is usually pretty consistant with their castings, its always a possibility it could be off - that's why you can buy 3 identical bikes and they all run a little different. Big benifit of a port job done right is all that stuff is checked and corrected.

 

[mxrcr4]

It has been like this since new, it revs but it just doesn't have much pull after midrange.

No, I did the jetting first, then the reeds, and then the pipe and silencer. All increased the mid, but if anything I have lost some off the top.

I have changed mains and needles leaner and richer and it is best where it is currently.

I will check the power valve cables again, but I did it twice using the exact directions that have been listed on this site.

I am kind of stumped!?!

 

[jrm]

Your bike should have plenty of top-end power. I agree with an earlier post suggesting you re-check the PV cables. When the actuator is turned completely clockwise, there should be 12 mm between the top of the RC valve actuator and the bottom of the cable adjuster on the back cable. Once you have the back cable adjusted for this 12mm setting, turn the actuator counter-clockwise as far as it will go. Adjust the front cable so it has minimal slack. It should have 1-2mm of "give," but no more. If it's close to touching the wall of the RC chamber it's too loose.

The owners manual is terrible on this point. A lot of the 02-06 CR250s that don't run correctly have RC valves that are not adjusted properly. Once you get yours properly adjusted, it should run very strong from mid to top.

 

[mxrcr4]

jrm, I did this exact adjustment twice. I used this precise method that was detailed on another post here. I even used a dial caliper to get my 12mm! I don't really know why my top end is lacking, I will go back through everything again and recheck timing, power valve adjustment., etc.

 

[steve125]

All the dyno charts i've seen, no bike peaks and falls off on top as fast as the 05/06 CR 250. The new 05 that I rode did just that.

I would send the cylinder and head to Eric.

 

[flattie]

first of all check your compression, maybe time for a top end!

 

[john3_16]

Steve is correct..The 05' CR has excellent HP numbers, but it doesn't hold it for very long and falls off as soon as it peaks...

Instead of buying V-Force 3 reeds, FMF SST pipe , and FMF shorty silencers the first thing you should do is get a port job...It is by far the most effective and cost efficient way to get what you want out of your motor...The bolt ons are more of a way to fine tune your bike...

Port it first or you will end up buying too many bolt ons and end up porting it anyway...

I've ridden a ported 04' CR250 that was so strong theres no way anyone could want more out of it...It was just that strong..

 

[mxrcr4]

True, true, I guess I will just pull it down and send it on to Eric for some of his magic. You got me real hopeful and excited with that it was so strong no way you could want more out of it! That's what I am talking about!

 

[oldfrt613]

I have a ported '05 ( same motor ) - wicked fast mid and up and bottom is decent.

 

[mxrcr4]

Did you have Eric port it? If so, did you get the mo better everywhere or ask for top end?

 

[oldfrt613]

Mo better is mo better !

 

[mxrcr4]

Sweet! Thanks guys!

 

[oldfrt613]

Happy trails !

 

[john3_16]

True, true, I guess I will just pull it down and send it on to Eric for some of his magic. You got me real hopeful and excited with that it was so strong no way you could want more out of it! That's what I am talking about!

Well...I had Eric port mine with "mo better" specs but I still haven't ridden it yet...My first ride should be this thursday...I pushed the kick starter down slowly after I assembled the top end and the bike has ALOT more compression as it was noticeably harder to push through the stroke...I could hear the bike sucking in air from the airbox with MUCH more authority than before....That's what I call a modded motor! You better use some race gas on that thing ! You don't want detonation to occur with that kind of compression for sure...VP C12 or VP red please!

The bike I rode belongs to my friend and was modded by Terry Varner...That bike has a crazy top end pull...It's like once you pass the midrange the bark changes pitch and just pulls harder the higher the rpms go...

I'm sure the motors are close..We're planning on doing a back to back comparison on a Varner cylinder VS Gorr and report on the performance of both bikes when we get a chance...

But from what I understand Gorr can deliver what you want...And if you want top end just let him know.

 

[NWetRider]

How would the 06 cr be after eric works his magic, for woods work that is? A local dealer has them for $4899.

 

[oldfrt613]

Don't know, I ride mine in the woods all the time, but I've always ridden mxers in the woods. I would imagine there are better picks for the woods. We have a YZ - has truly amazing response right off idle - depends on how you ride - if your agressive the CR would be ok, though not my first pick. Who's the dealer and were, that's a good price for an '06 - '05 is identical if he has any of those left for less moola.

 

[mxrcr4]

Man, that is a great deal on the 06.

Please give us a report on your thoughts when you get to ride it. And yes, I always run C12.

 

[NWetRider]

The deal is at motosport outlet in Hillsboro Oregon. I think they want $250 for set up. They have some in the crate though so I would try to get one of these. I'll probably buy something else for woods but I was curious because of the price.

 

[pace]

That shorty silencer likely isn't helping your top-end any. Most people fit 'em for low-end response, not overrev.