ADVrider

Go Back   ADVrider > Bikes > Thumpers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old Yesterday, 01:49 PM   #1
cjbiker OP
Nobody's Robot
 
cjbiker's Avatar
 
Joined: Aug 2010
Location: Southern Maine
Oddometer: 2,474
2008 KTM 250XCF-W Project

I'm starting this thread with the intention of keeping track of the winter project I just took on, a 2008 KTM 250 XCF-W.

I started thinking this summer that I'd like a bike somewhere in between my Honda XR250R and KTM 200 XCW. Something with a more planted feel and linear power like the XR, but with modern suspension and decent top-end power like the 200. A 350 EXC-F would be ideal, but way out of my price range. After a lot of internet research, I was leaning towards a Honda CRF250X. I'm an admitted orange Kool-Aid drinker, so when a 2008 250 XCF-W came up for sale locally, I started doing research into that. Everything sounded good. About half the reviews said it was a little soft on low-end power, the other half said it was good for a 250F. Everyone agreed they rip up top. The 250 has the RC4 engine which doesn't have the issues of the 2008 450/530 and is reported to be very durable for a 250 four stroke race engine.

After several rounds of missed appointments, tons of emails, phone calls, I finally got to check the bike out. It looked clean and has a ton of extra parts. On the test ride, however, it wouldn't rev past 1/4 throttle or so. I made the guy what I thought was a fair offer, hoping it just needs carb work, but low enough that if it needs motor work, I won't be too deep under water with it. He accepted the offer, and I hauled it home.

Here it is in all it's hideous glory:



I've never really liked the looks of this generation of KTM, and the black headlight mask, bare shrouds and supermoto fender really make it ugly. So, the first thing to do was get some stock plastics on order for it.

The next thing to do is roll it into the basement for tear-down. Before I could do that, I had to finish taking apart this 1998 XR250R with a bad top-end that I'm parting out.



Done:





I then rolled the KTM into the workshop.



At this point I hit the first setback. I had looked at the air filter when I checked the bike out, and it was dirty, but appeared intact. Unfortunately, I discovered that the support cage is missing, so the poor bike has been eating dirt for who knows how long.



Not cool. I had been thinking that if I really like it, I'd do a big-bore kit some day down the road. Well, that may happen sooner, rather than later. I pulled the plug, and it's all carboned up. You can see the top of the piston through the spark plug hole, and it's equally crusty.



So, I dragged it back outside and gave it a good bath in 36 degree weather. Don't want any dirt clods falling down inside the engine when I start tearing it apart.



So at this point, I'm weighing my options. I could clean it up and run it and see how it goes, but I might as well get it fixed up over the winter so it's good to go for riding season. I'm leaning towards the Thumper Racing 300 kit. I can send them the cylinder to install the liner and the head to have it checked over. Then I should have a solid bike for a good long time.

cjbiker screwed with this post Yesterday at 02:01 PM
cjbiker is online now   Reply With Quote
Old Yesterday, 02:09 PM   #2
clapped_r6
The Spoad Warrior
 
clapped_r6's Avatar
 
Joined: Jan 2006
Location: Ridgefield, WA
Oddometer: 2,672
nice, looking forward to your writeup. i have a friend in the Exact Same Boat, who will no doubt find this good info
clapped_r6 is offline   Reply With Quote
Old Yesterday, 02:29 PM   #3
cjbiker OP
Nobody's Robot
 
cjbiker's Avatar
 
Joined: Aug 2010
Location: Southern Maine
Oddometer: 2,474
Another part of this project, one that I was expecting, is to redo the wiring. The kid I bought it from admitted that he's not much of a mechanic, and I'm hear to say that he's even worse at wiring. The bike has a Baja Designs kit. I dual sported my KTM 525 EXC, and it has about 1/4 the stuff that the BD kit has. I'll be removing the key switch and cleaning up the wiring quite a bit.

cjbiker is online now   Reply With Quote
Old Yesterday, 02:54 PM   #4
ChasM
Gnarly Adventurer
 
Joined: Nov 2007
Location: Loomis, CA (Sacramento area)
Oddometer: 243
Nice looking bike.

I highly recommend the 350 conversion. My '08 250 XCF-W was converted back in July 2008 by HTRacing and I have been riding it ever since then. It has always been a wonderful dependable bike with at least as much power and torque as the modern 350 XCF-W. Even though the engine still ran like a top, I had HTR go through the engine in 2013 after 8,000+ miles and 395 hrs. They found that the engine was still in excellent condition overall. They replaced the rings and the exhaust valves. The piston, cylinder and bottom end were still in very good condition. Note that the valves had never needed adjustment during this time.
__________________
Trailbike Sportsmen Assoc/AMA
'14 BMW R1200GS LC
'09 Beta 565 RS (with Revloc)
'08 KTM HTR 350 XCF-W(Revloc
'74 Norton 850 Commando
ChasM is offline   Reply With Quote
Old Yesterday, 02:58 PM   #5
cjbiker OP
Nobody's Robot
 
cjbiker's Avatar
 
Joined: Aug 2010
Location: Southern Maine
Oddometer: 2,474
Sounds awesome, but at $1900, that would really blow the budget for this project.
cjbiker is online now   Reply With Quote
Old Yesterday, 03:24 PM   #6
GR0NK
Got some screws loose!
 
GR0NK's Avatar
 
Joined: Sep 2006
Location: In the Valley of Bomb Runs...
Oddometer: 1,802
I have the 07 version.



It's my woods racer for Hare Scrambles, XCs, even the odd Enduro if I don't need a plate. I put a fresh top-end in it at 105 hours, well past the recommended interval. I found the ring end gap was well past the service limit. Service limit is 1mm IIRC and it was at 4mm when I took it apart. Still wasn't smoking mind you.

I absolutely love the RC4 motor, it's a rock-solid design. I may do a big bore with it someday but I'm really enjoying it as a 250. It has proven to be very strong for a 250 and very reliable as well. During the 2011 (or 2012 I can't remember) Corduroy Enduro I lost the shifter in the timed MX section. I bounced that little motor off the rev limiter for almost ten minutes straight and it stayed together. I later found the shifter and completed the rest of the day. (140kms total)

BTW, the motor isn't really that soft off the bottom, it's just that the wide-ratio transmission lets the motor fall off the cam if you don't wind it out in the previous gear. But even geared for the woods it will still run out past 80mph in top gear. Put yours back together properly and it will run strong for a long time.



Sean
__________________
Team Valley Bomb Squad

Nullus Vereor ex Terra Incognita
GR0NK is offline   Reply With Quote
Old Yesterday, 03:36 PM   #7
cjbiker OP
Nobody's Robot
 
cjbiker's Avatar
 
Joined: Aug 2010
Location: Southern Maine
Oddometer: 2,474
Thanks! I have a 2007 200 XC-W and a 2006 525 EXC. I love the looks of that generation KTM, but I wanted to try the next gen. They say the suspension and handling is much improved. I've ridden a 2009 200 and it turns way better than my 2007, so I'm really looking forward to this one.

I'll definitely open the motor up and see how it looks before I decide what to do. If the bore looks good and it just needs rings, I'll do that. If the cylinder is trashed, then it's big-bore time!
cjbiker is online now   Reply With Quote
Old Yesterday, 04:09 PM   #8
GR0NK
Got some screws loose!
 
GR0NK's Avatar
 
Joined: Sep 2006
Location: In the Valley of Bomb Runs...
Oddometer: 1,802
Quote:
Originally Posted by cjbiker View Post
Thanks! I have a 2007 200 XC-W and a 2006 525 EXC. I love the looks of that generation KTM, but I wanted to try the next gen. They say the suspension and handling is much improved. I've ridden a 2009 200 and it turns way better than my 2007, so I'm really looking forward to this one.

I'll definitely open the motor up and see how it looks before I decide what to do. If the bore looks good and it just needs rings, I'll do that. If the cylinder is trashed, then it's big-bore time!
Lol. I used to race a 2007 200XC...



...and have an 05 525EXC.




I race Vet and Vet Expert so I prefer the slower handling of the older bikes.



Sean
__________________
Team Valley Bomb Squad

Nullus Vereor ex Terra Incognita
GR0NK is offline   Reply With Quote
Old Yesterday, 06:06 PM   #9
cjbiker OP
Nobody's Robot
 
cjbiker's Avatar
 
Joined: Aug 2010
Location: Southern Maine
Oddometer: 2,474
I don't want to tear into the motor until I get a service manual. So with nothing better to do, I pulled the carb. I love how easy it is to work on this bike. Undo a few bolts, and the whole subframe can swing up. The carb is then very easy to remove.



I removed the bowl, hoping to find that the main jet had fallen out or something else that would explain why it wouldn't rev past 1/4 throttle. Unfortunately, the bowl was very clean and all the jets look good.



The throat of the carb is filthy with oily dirt, and there is a lot of milky oil in the breather hose. I'm thinking the milkyness is because it was 25 degrees when I test rode it, and the engine didn't get warm enough to boil off the condensation.

Any ideas on why it wouldn't rev? Would the crusty spark plug do that? Something else?
cjbiker is online now   Reply With Quote
Old Yesterday, 06:42 PM   #10
GR0NK
Got some screws loose!
 
GR0NK's Avatar
 
Joined: Sep 2006
Location: In the Valley of Bomb Runs...
Oddometer: 1,802
First guess, vacuum release plate is reversed. Pull the slide out and make sure it's installed just like in the manual.





Sean
__________________
Team Valley Bomb Squad

Nullus Vereor ex Terra Incognita
GR0NK is offline   Reply With Quote
Old Yesterday, 06:55 PM   #11
cjbiker OP
Nobody's Robot
 
cjbiker's Avatar
 
Joined: Aug 2010
Location: Southern Maine
Oddometer: 2,474
Nope, it was in there correctly.
cjbiker is online now   Reply With Quote
Old Yesterday, 07:18 PM   #12
GR0NK
Got some screws loose!
 
GR0NK's Avatar
 
Joined: Sep 2006
Location: In the Valley of Bomb Runs...
Oddometer: 1,802
Is it popping or doing anything strange when you try to rev it or it runs good but just won't rev?

You replaced that crusty spark plug right? Check the spark plug boot and all the ground wires.



Sean
__________________
Team Valley Bomb Squad

Nullus Vereor ex Terra Incognita
GR0NK is offline   Reply With Quote
Old Yesterday, 07:48 PM   #13
cjbiker OP
Nobody's Robot
 
cjbiker's Avatar
 
Joined: Aug 2010
Location: Southern Maine
Oddometer: 2,474
Yeah, it bogs and cuts out. I was able to feather the throttle and get it to rev up once, and it really took off. Haven't ridden it since the test ride. Just pulled the plug this afternoon.
cjbiker is online now   Reply With Quote
Old Yesterday, 08:33 PM   #14
GR0NK
Got some screws loose!
 
GR0NK's Avatar
 
Joined: Sep 2006
Location: In the Valley of Bomb Runs...
Oddometer: 1,802
Quote:
Originally Posted by cjbiker View Post
Yeah, it bogs and cuts out. I was able to feather the throttle and get it to rev up once, and it really took off. Haven't ridden it since the test ride. Just pulled the plug this afternoon.
Did the needle fall out of the clip?





Sean
__________________
Team Valley Bomb Squad

Nullus Vereor ex Terra Incognita
GR0NK is offline   Reply With Quote
Old Yesterday, 08:42 PM   #15
cjbiker OP
Nobody's Robot
 
cjbiker's Avatar
 
Joined: Aug 2010
Location: Southern Maine
Oddometer: 2,474
No, that was on my list, too. Nothing wrong with the carb.
cjbiker is online now   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 05:11 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014