[P99]

CRF250X with R Head

Good Day,

2005 CRF250X
- 07 R head
- KBW Valves and Springs
- Hot Cams Stage 1
- Weisco reg comp piston
- Q4
- Air Box Open
- O-Ring Mod
- Boyssen Quick Shot
- No Back Fire Screen
- Twin Air Filter
- 0 - 2000 Feet
- 60 - 75 F
- 42 Pilot
- 170 Main
- 1.75 turns out on the screw, any more or less seems to bring on the "BOG", turning the screw out reduces the popping on decel but increases the bog.
- Red Needle, 4th position, tried 5th, but mid range seemed to suffer
- Currently running 13x49, planning to change to 13x52
- Tight single track 90% of the time
- Ok power bottom to mid
- Awesome mid to top end, much better than with the X head and stock cam.
- Popping on decel, more when hot
- No problems starting, when hot need to use hot start lever

Would like to improve bottom to mid and reduce popping on decel if possible
Bottom to mid, power is there but not very "snappy"
Mid to top end, very "snappy".
Expect that the change in gearing will have me riding in the mid range more of the time, but would like to improve the bottom to mid if possible.

Any suggestions very much appreciated.

Brgds, P99

[paul turner]

I believe you're a tad rich all around for your location and temp/humidity.
Try 3rd position, and maybe a 165 main.


paul

[P99]

Good Day Paul,

Many thanks for the advice.

Went back to the stock AP cover, changed needle to the 3rd position, main jet unchanged (will change shortly), bike running much better. Much smoother power from idle to 3/4 throttle, top end good, but now feels a bit sluggish,(will try smaller main jet). Fuel Screw 2 turns, will try adjusting this as getting a bit more crackle and pop on decel.

Thanks again for the advice.

Brgds, P99

[P99]

Thanks again for all your help.

Elevation: 0 - 1,000
Temp: 35 - 45

Have tried the following:
165 Main
42 Pilot
Red on 3rd clip
Screw: 1 and 3/4
Results: Great top end, good mid, ok low

168 Main
45 Pilot
Red on 3rd Clip
Screw: 1 and 3/4
Results: Ok top end, (didn't have as big a hit as with the 165), better mid, ok low
Plug: Center was "medium tan"

Tonight going to try:
165 Main
45 Pilot
Red on 4th clip
Screw: expect 1 and 1/2 to 1 and 3/4

Also will mark the throttle and really try to concentrate on what is happening at the different throttle openings

Brgds, P99

[P99]

Latest Attempt to get it right.

165 main
45 pilot
4th clip
1.5 screw

Pretty good, almost no pop and crackle on decel. Zero bog, mid is OK and top end is very good. Probably could go back to the third on the clip to make the mid more crisp. Will pull the plug tonight and take a look.

But overall, so far best set up.

Thanks for everyones help in getting this dialed in. Overall the bike is running the best it's ever been. Who needs a 450 when a 250 can scare the @#$$@ out of you! Also, now running without the powershot, bike runs just as good, no difference. So I can't recommend it, or the power wing thingamigy, spend your money elsewhere. Like a down payment on knee braces or a new helmet.

Had a great ride at McNutt today, 5hrs of awesome technical single track, the bike never missed a beat. That can't be said about the rider, unfortunalty hit a tree, so will be straightening a rad guard tonight.

My set up
2005 250X
07 R Head
Kibblewites
Hot Cam Stage 1
FMF Power Bomb
FMF Q4
JD Needle 4th
45 Pilot
165 Main
1.5 Screw
A couple of red anodized aluminum plugs, dip stick, case saver, etc
WC guards all over the thing
Rekluse, with rear hand brake, no clutch
Dunlop 805 rear tire
Stressed and cracked plastic, next purchase: New Plastic!

Thanks again for your help, learned alot about jetting.

If anyone has any suggestions on getting it to run better would be pleased to hear.

P99

[P99]

Further to the last post. Pulled the plug and found it be a bit darker than previous, bike ran pretty good, no issues anywhere. Was hard to start when cold, but when warmed up was fine.

Going back to 3rd clip, 45, 165, 1.5 turns and see how that is. Expect it be a bit leaner, probably crisper in the mid and maybe easier to start when cold. With the clip at the 4th position not as much snap in the mid range,

Keep seeing 5th clip set ups, wonder if I decrease the main to say 160 or 162 if I can run the clip lower. So far having the clip leaner has been better, but thats with the 165 which seems to be the best for the top end.

Is there any benefit to running the clip in a richer position? Should I try to lean out the top end so that I can run a richer needle. So many combinations!!!

Guess if it feels good, no bog, instant power and it pulls strong to red line I should be happy and quick messing with the thing.

Anywhere else I should be looking to improve the overall perfomance, besides my riding skills or lack thereof.

Also, recall a thread about being to slow to return to idle when revved on the stand. But can't recall or find the thread that discussed this. Find that when cold this occurs for the first few minutes, twists, but all is ok once warmed up.

Brgds, P99

[Asmith]

Also, recall a thread about being to slow to return to idle when revved on the stand. But can't recall or find the thread that discussed this. Find that when cold this occurs for the first few minutes, twists, but all is ok once warmed up.

Brgds, P99

Slow to return to idle ( hanging idle ) is due to being too lean on the pilot circuit. That would also explain hard starting.

Go to 1 3/4 or 2 turns out on the fuel screw.

[450xL.W.]

+1 on lean pilot circuit