CRF 250X Upgrade

[a454elk]

Well, I just picked up my 250X after having some great work done on it. It went from stock to the following changes:

FMF Q4 pipe and powerbomb header pipe
160 Main jet change
Airbox opened up
Hot Cams stage one cam
Changed to the "R" piston higher compression 13:1

Stock sprokets but I changed to the CRF450 needle in the 3rd clip I believe.

I have the stock dyno results to post and will do so when I have the bike dynoed now after the changes that way you can hopefully see the difference. Ol89'er did the work and he did an outstanding job, thank you again Terry. ;)

I rode the bike at his shop, through his house and around his horse arena and WHAT A DIFFERENCE!! The bike has a whole lot more bottom end and pulls through the powerband. I'm real happy with the work and will post a ride report when this rain stops! I'll also post the dyno results as soon as I can get it done, hopefully in the next week or so. I suggest this work for anyone that wants to bump up the 250X a bit while keeping the reliability high. From what I was told by Terry, the valves looked great and I'll probably change over to the Kibble Whites when I do the next top end.

I think Terry is going to offer this package in the near future if anyone is interested. :nod:

 

[JWW]

I think Terry is going to offer this package in the near future if anyone is interested. :nod:

If this is true I can tell you from experience that he does great work and my X will going to him when it needs valves.

 

[Ol'89r]

Thanks guys. :cool:

The 250X is one plugged-up lil' puppy. The trick to making them run is to make them breath. This combination along with a mild port job does wonders to unveil the hidden power in the X. The 450X isn't much better and can use the same treatment.

The addition of the Kibblewhite stainless valves and spring kit makes for a very bullet-proof package.

Thanks again.

 

[SpDyKen]

I was wondering if you had done any port clean-up to Elk's engine, 89r.

Any pics. of Elk riding the bike through your house? I'd like to see those! I've pushed many a bike through, but never ridden through a house!

Thanks for the info., both.

 

[Rich Rohrich]

Sounds like an excellent combination 89r. Looking at the stock cam timing and stock configuration of the X models especially the California versions, they seem like they are just begging for a package like you put together. :cool:

I'm looking forward to hearing Elk's thoughts after he gets a chance to really put some time on the new package.

 

[Ol'89r]

I was wondering if you had done any port clean-up to Elk's engine, 89r.
.

Yes Ken. I do a mild clean-up port job which involves blending and matching the seats to the ports and smoothing the irregularities. The ports in their stock condition are very good and do not require much work. Spending a lot of money on a full port job is a waste of money IMO.

Elk only thought he rode through my house. Actually it was my barn. When he picked up his bike and road tested it, it had so much more power than what he was used to, he went out of control and bounced off the arena fence and through the barn. :yikes: He was so excited by the time he got the throttle shut off, I told him he rode through my house and he believed it. :laugh: JK. :rotfl:

Rich.

The California model is so plugged-up they barely run with the stock jetting. Anything you do to them is a big improvement. I am anxious to see the torque readings from the dyno test.

 

[Rich Rohrich]

I am anxious to see the torque readings from the dyno test.

Me too :nod:

 

[mideastrider]

Looking forward to hearing more when you get the ride and the dyno in.
I bought my son a new 06 250x. So far I've put a jardine full system on it.
Opened up the air box and installed a jet kit and needle. Thats helped out alot.
I have the stage one,but not installed it yet.
I question what the compression ratio of my stock piston is. Honda says it has got the 13.1 in it. But i've read on the internet that it does not.
Did you go with an OEM "R" piston or wiseco 13.1?

 

[Ol'89r]

I question what the compression ratio of my stock piston is. Honda says it has got the 13.1 in it. But i've read on the internet that it does not.
Did you go with an OEM "R" piston or wiseco 13.1?

Not exactly sure but from comparing the two, your piston is more like 10 or 11:1. Going to the 13:1 piston makes the bike more responsive off of the bottom. We used the Wiseco 13:1 piston. Basically the same piston as the "R".
One of the best parts of this conversion is the exhaust system. It gives good power and is very quiet. More so than the stock exhaust system.

 

[a454elk]

I plan on getting it on the dyno hopefully this week. I have the stock dyno results already so I'll compile them and post it. Just riding it through Terry's house gave me a sense of the unleashed power available. :) If this rain will stop I can take it out and ride it already! Stay tuned.....

 

[Kzoo]

well what happen. Did you Dyno bike?
:ride:

 

[Ol'89r]

Not yet.

He hasn't even had time to ride it yet.

 

[a454elk]

Ok, here's the long awaited ride report! Sorry for the delay folks.

With the FMF Q4 pipe, the noise was kept to a minimum. I was extremely pleased with the sound output through the gears and rpm range. We rode in the national forest so the built in spark arrestor came in handy.

At the beginning of the trail, I only needed 2nd and 3rd gear. When I approached whoops or water crossings, I was able to throttle at the last minute and pull the front end up with ease. It was nice to have the same weight bike with more power! The reason I enjoy the bike so much is that it feels light and I don't get tired riding it all day.

Hill climbs were no problem, I could stay in 2nd or 3rd and slow my speed. The torque kept the bike moving with minimal wheel spin. At one point, I almost came to a stop in 2nd gear in a rut on an uphill climb and without clutching it, I twisted the throttle slightly and it pulled right through it without killing the motor. That really impressed me the most during the ride.

One thing I had to deal with was wheel spin on flat turns. Before the motor work, I could throttle through flat corners with no worries of losing the rear end. Today, I did the same and the rear end slid out so I had to shift my weight back and weight the outside foot which helped guide me through it. Not that I'm complaining Terry but it was something to keep in mind now. ;)

We rode for a few hours, starting and stopping, shutting the bike off and leaving it running with no problems of overheating, pinging, or hard starting. The elevations ranged from around 3000 ft to over 5000 ft. The bike ran great throughout the elevations with no power loss. The temperature was around 40 degrees give or take which made it a great day for a ride with some friends, and Thumbs.

Speaking of Thumbs, just a little insight if you ride with him. If you think you're being nice when you slow everyone down to traverse a river crossing, think again. The last thing you'll here is the sound of his two-smoke as he revs past you and fills your boots, jacket, hood and gloves with water! Thanks bud, I owe you.

Hope this ride report helps, I recommend the same set-up for your 250X of you're looking for some bottom and mid pep. Terry will take care of you so give him a shout. Thanks Terry, you rock! I'll work on the dyno as soon as possible.
Elk

 

[Ol'89r]

Thanks for the report elk.

Glad you liked the power. :cool:

That is the difference in building an engine for usable torque as opposed to building one just to sell exhaust systems.

Thanks again.