GasGas Riders Club Forum  

Go Back   GasGas Riders Club Forum > Other Bikes... > All Other Bikes...

All Other Bikes... KTM, Husky, VOR, Husaberg & Hondayamazuki...


Reply
 
Thread Tools Display Modes
  #1  
Old 09-06-2016, 09:43 PM
coopernicus's Avatar
coopernicus coopernicus is offline
Platinum Level Site Supporter
 
Join Date: Sep 2009
Location: Denver, Co
Posts: 257
Default KX 250 2T in a KX250f Aluminum Frame

A lot of folks think about installing a 2 stroke motor into a modern 4 stroke aluminum frame and I have been wondering about this for many years. I recently had to chance to buy a 2007 KX250f frame with a mid nineties KX250 2T motor (bored out to 299cc) installed. I was also very lucky in early July to find a 2003 KX144 that is close enough to a 2007 KX250 to make a rough comparison in ergonomic "feel". Ideally, I would have preferred a '13 or newer KX chassis as that is the year when the KX frames were upgraded to more ergonomically narrow and forgiving ride characteristics.

My initial thoughts on the bike without having ridden it, yet, is that it feels more bulky across the pegs, midsection, and in the rear where the right side number plate bulges outward for the 4T exhaust cannister. It is bulkier than my '14 GG 300 and substantially more bulky than the steel framed '03 KX144. The steel framed 2007 KX 250 (2T) is listed as 214 pounds dry (97kg dry, 226 pounds wet with no gas) and the AF framed 2T weighs 238 pounds (108.2kg) with all fluids, 1 gallon of gas, FMF Turbine Core II, and Maxxis Desert IT tires). If someone is looking to drop some weight by doing this conversion, I don't think it will save you much. It is possible that it weighs more than the equivalent steel 2T frame from the same year KX. What is the advantage that I see at this time? It really looks good!! That's about all I can say before having a chance to ride it on some real trails (coming soon). If the ride quality is not there, then I won't bother to try and put a GG motor into it. For now, I will have to be content with just how good this bike looks!




Eric


__________________
2014 GG 300 Racing E
2002 ATK 605 Dual Sport
1974-86 Vintage Can Ams, SWMs, Puchs, etc.

Last edited by coopernicus; 09-06-2016 at 10:08 PM. Reason: embedded a picture
Reply With Quote


  #2  
Old 09-06-2016, 10:03 PM
gasgasman's Avatar
gasgasman gasgasman is offline
Super Moderator
 
Join Date: Jul 2006
Location: Pearland Texas
Posts: 4,031
Default

Cool bike. Thanks for sharing.
Reply With Quote
  #3  
Old 09-07-2016, 04:39 AM
(F5)'s Avatar
(F5) (F5) is offline
Gold Level Site Supporter
 
Join Date: Jul 2006
Location: Wellington New Zealand
Posts: 1,161
Default

Wonder if it will feel less top heavy, not that the gasser particularly does. Lighter is always nice. Top lightness makes it feel lighter than it is
__________________
'07 EC300
496 CPI Cheetah RZ/RGV hybrid
675 Street Triple R
RS125 framed MB100 racer
Stinger T125 Suzuki
Reply With Quote
  #4  
Old 09-21-2016, 12:26 AM
coopernicus's Avatar
coopernicus coopernicus is offline
Platinum Level Site Supporter
 
Join Date: Sep 2009
Location: Denver, Co
Posts: 257
Default

I had the chance to ride this bike extensively this past Saturday and have concluded that I would not bother to make the 4T AF conversion to a 2T motor. The bike had a slightly less top heavy feeling than me 2014 300 Racing E but the width from the pegs to the seat made it more cumbersome. The main drawback compared to a standard KX 250 2T and a GG 300 is the lack of steering precision. It feels a little vague in the turns and does not give the best feedback to the rider as to how far you can "push" the traction on the front tire (which, although new, is a CST brand tire...ewww!). Frankly, this did not surprise me too much given past test reports of the 07 KX250F and the less weight of the KX 2T motor. As for the suspension, this bike has a Race Tech components installed and the suspension is good. However, it is not as good as the bone stock Marzocchi/Reiger combo on my GG. What did I like about the bike besides the 299cc KX motor? The feel of the aluminum frame was far better than anticipated. It was not overly stiff and it did not feel harsh at all. It also had an excellent turning radius compared to my GG (big surprise). I must add, if anyone has a KX 250 that they want to keep, making it a 300 made the motor very nice. I've ridden extensively a big bore YZ and the KX big bore motor is much better for trail and race speeds. The big bore was done by Kustom Kraft but can be done by most other places (Powerseal did the YZ conversion). I don't know if I will keep this bike but I will test it some more after I make some mods to get more "bite" in the front end and I will replace the front tire, too. Feel free to ask my any questions if you are interested in an AF conversion!

Eric
__________________
2014 GG 300 Racing E
2002 ATK 605 Dual Sport
1974-86 Vintage Can Ams, SWMs, Puchs, etc.
Reply With Quote
  #5  
Old 09-21-2016, 03:06 PM
twowheels's Avatar
twowheels twowheels is offline
Senior Member
 
Join Date: Oct 2009
Location: Dearborn MI
Posts: 1,859
Default

Quote:
Originally Posted by coopernicus View Post
I had the chance to ride this bike extensively this past Saturday and have concluded that I would not bother to make the 4T AF conversion to a 2T motor. The bike had a slightly less top heavy feeling than me 2014 300 Racing E but the width from the pegs to the seat made it more cumbersome. The main drawback compared to a standard KX 250 2T and a GG 300 is the lack of steering precision. It feels a little vague in the turns and does not give the best feedback to the rider as to how far you can "push" the traction on the front tire (which, although new, is a CST brand tire...ewww!). Frankly, this did not surprise me too much given past test reports of the 07 KX250F and the less weight of the KX 2T motor. As for the suspension, this bike has a Race Tech components installed and the suspension is good. However, it is not as good as the bone stock Marzocchi/Reiger combo on my GG. What did I like about the bike besides the 299cc KX motor? The feel of the aluminum frame was far better than anticipated. It was not overly stiff and it did not feel harsh at all. It also had an excellent turning radius compared to my GG (big surprise). I must add, if anyone has a KX 250 that they want to keep, making it a 300 made the motor very nice. I've ridden extensively a big bore YZ and the KX big bore motor is much better for trail and race speeds. The big bore was done by Kustom Kraft but can be done by most other places (Powerseal did the YZ conversion). I don't know if I will keep this bike but I will test it some more after I make some mods to get more "bite" in the front end and I will replace the front tire, too. Feel free to ask my any questions if you are interested in an AF conversion!

Eric
Great looking conversion Eric! Ditch the front tire and maybe lower the front spring rate and report back ...
__________________
Steven Beane #275
PlusOnePerformance - Superior Service the World Over - Dearborn MI
AMA District 14 (Michigan) Officer

afterhourscycle.com
Michigan's Beta and TM Race Headquarters
Reply With Quote
  #6  
Old 09-22-2016, 01:49 AM
swazi_matt swazi_matt is offline
Senior Member
 
Join Date: May 2010
Location: From Swaziland, Now Hamilton New Zealand the “look but don’t touch” enduro heaven
Posts: 1,939
Default

Bike looks great, but I always thought the conversion to do for extreme riding was to fit a Kdx motor in the 250f frame
__________________
2010 ec 300
Reply With Quote
  #7  
Old 09-23-2016, 12:46 AM
coopernicus's Avatar
coopernicus coopernicus is offline
Platinum Level Site Supporter
 
Join Date: Sep 2009
Location: Denver, Co
Posts: 257
Default

Quote:
Originally Posted by swazi_matt View Post
Bike looks great, but I always thought the conversion to do for extreme riding was to fit a Kdx motor in the 250f frame
Matt,

You could read my mind from that far away? Used KDXs are very inexpensive here and I recently bought two KDX 220s and was looking for a KX250F rolling chassis to make the conversion. So "yes", an AF KDX was originally my goal. While looking for the KXF chassis, I spotted this bike for sale and, since it was already complete, riding it would let me know if I wanted to go through the effort myself. The answer is most likely "no", it's not worth it. I also found a website where someone put a KDX motor in a KX 125 steel frame and he says it works very well (https://haroldbawlzangya.com). I have a 2003 KX125 and sitting on the AF KX and the steel framed KX (one after the other) shows me how much better the feel is of the ergonomics on the steel framed bike. So now you know the whole story!!

On a side note, for all of you folks outside of the US, if you want to see what the used motorcycle market is like here in the city where I live, follow the link below. My family in the UK is always amazed at what we have here and the prices!

http://denver.craigslist.org/i/motorcycles

Eric
__________________
2014 GG 300 Racing E
2002 ATK 605 Dual Sport
1974-86 Vintage Can Ams, SWMs, Puchs, etc.
Reply With Quote
  #8  
Old 09-23-2016, 09:14 AM
hadfield4wd hadfield4wd is offline
Senior Member
 
Join Date: Oct 2015
Location: Roanoke, VA
Posts: 814
Default

The kdx motor in a 125 chassis is a very common hybrid. But for less money you could just buy a gg200. I looked into it and had the kdx motor and was going to put it in a CR250 AF, because that is what I had. Was just going to be more money than I wanted to spendZ
__________________
Matt

1999 GG EC 250 Six Days
1996 BMW R1100RSL
2001 Triumph Speed Triple
2002 Suzuki SV650 for my 19 year old
2000 GG XC250 for my 19 year old
2004 Kawasaki Mojave 250 for my 16 year old
1997 KDX 200 for my 16 year old
2003 Honda Rancher 350 for the wife
Reply With Quote
Reply



Thread Tools
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 Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Aluminum Air Box FreeLife Enduro Intake/Carburetion - 2 stroke 5 06-03-2015 06:15 PM
Link to WEC Heinola Finland Frame by Frame REVERUP Pictures & Videos 0 09-16-2012 10:31 PM
GG Aluminum Frame ruca Pictures & Videos 21 05-03-2011 06:29 PM
2002 frame; same as a 2005 frame, or close enough? Trooper Sam Enduro Chassis & Body 0 06-10-2010 10:18 AM




All times are GMT -5. The time now is 11:03 PM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright 2009 - GasGasRider.org