Hybrid Plunge

Discussion for swapping a KDX motor in a MX frame...
User avatar
80elkster
Supporting Member II
Supporting Member II
Posts: 135
Joined: 08:43 pm Jan 01 2006
Country:
Location: Maple Valley WA

Post by 80elkster »

So Hybrid you used the reamer all by itself?? No drilling. Hmmm thats good to know as I will be doing a hybrid soon.
06 DR650 Farkled
91 WR250 2T
00 300EXC (Sold)
79 XS850 (Sold)
79 CR250 (Sold)
78 IT400 (Stolen)
75 G5 100 Kawi (Gave it away)
73 F7 175 Kawi (Sold)
70 175 Brigestone (Recycled)
05 KDX200(Son's)
93 KDX200
75 KT250 Trials
250 Quads
Just glad to be ridin!
hybridracing65
Member
Posts: 63
Joined: 11:15 am Feb 21 2010
Country:

Post by hybridracing65 »

>|<>QBB<
80elkster wrote:So Hybrid you used the reamer all by itself?? No drilling. Hmmm thats good to know as I will be doing a hybrid soon.
I did use drill bits to scale up till it was close to 17mm and then used the reamer.
Was just surprised the reamer went through easier then the drill bits.
market
Member
Posts: 27
Joined: 04:33 am Apr 30 2011
Country:

Post by market »

Hi, it's my first post in this forum....i've got an '04 cr125 frame and i want to build a hybrid too.....what about the lining of the sprockets??

thanks!!!
:prayer:
User avatar
scheckaet
KDXRider.net
KDXRider.net
Posts: 3740
Joined: 12:09 am Nov 10 2005
Country:
Location: edmond oklahoma

Post by scheckaet »

there's a few CR hybrid post in the hybrid section you should check it out.
welcome to the site.
market
Member
Posts: 27
Joined: 04:33 am Apr 30 2011
Country:

Post by market »

thank you....i was reading about che cr hybrids but noone wrote nothing about the sprockets....so i guess that they are ok.... :hmm: :hmm:
User avatar
KDX Butterfly
Queen B
Queen B
Posts: 2063
Joined: 05:12 am Aug 04 2007
Country:
Location: Cedar Grove, Tennessee

Post by KDX Butterfly »

>|<>QBB<
market wrote:Hi, it's my first post in this forum....i've got an '04 cr125 frame and i want to build a hybrid too.....what about the lining of the sprockets??

thanks!!!
:prayer:
welcome, market!!!
"If I were just two inches taller, I wouldn't be me." ~KDX Butterfly
chopper
Member
Posts: 31
Joined: 10:55 pm Nov 24 2010
Country:

Post by chopper »

I am building a hybrid with a CR125 chassis also. To get the motor mounted with the sprockets in line you need to have your swingarm bushings cut down to 47mm in length, I believe that they are 54mm and 59mm on the stock bike. Once you bore the hole in the cases to 17mm you'll have the rear of the motor set.
market
Member
Posts: 27
Joined: 04:33 am Apr 30 2011
Country:

Post by market »

thank you so much chopper!

both of them have to be milled at to 47?

which year is your bike? mine is a '04 and as far as i know the from '02 to '07 the frames and swingarms are the same....am i right?

thank you! :razz: and sorry for so many questions.....
chopper
Member
Posts: 31
Joined: 10:55 pm Nov 24 2010
Country:

Post by chopper »

Yes both need to be 47mm, 02-07 are the same, mine is an 07.
hybridracing65
Member
Posts: 63
Joined: 11:15 am Feb 21 2010
Country:

Post by hybridracing65 »

>|<>QBB<
chopper wrote:Yes both need to be 47mm, 02-07 are the same, mine is an 07.
Hi, mine is an 03cr125.
No problem with alignment.
In fact the bottom factory frame motor mount and the bottom kdx motor lined right up perfectly after you slide the swingarm bolt through.
Had to shave the welds on the front of the frame to clear the powervalve covers, and cut the swingarm bushings as specified, but thats it. The only mount that required modification was the front motor mount.

A freind of mine who recently done and 04 KX125 conversion has had trouble with sprocket alignment.
He says the motor a little low and that the chain needs to be run excessivly loose and he is not comfortable with that.
I was wondering if anyone else has had this problem with the kx builds.
User avatar
Tedh98
Supporting Member II
Supporting Member II
Posts: 1576
Joined: 01:08 pm Mar 20 2009
Country:
Location: Atlanta, Georgia
Contact:

Post by Tedh98 »

>|<>QBB<
hybridracing65 wrote: A freind of mine who recently done and 04 KX125 conversion has had trouble with sprocket alignment.
He says the motor a little low and that the chain needs to be run excessivly loose and he is not comfortable with that.
I was wondering if anyone else has had this problem with the kx builds.

I didn't have that problem with the two '04 KX builds I've done. I didn't even bother using the KX chain specs due to having a different engine in the bike. To get the right chain tightness, I followed the procedure where you remove the shock and then rotate the swingarm to get the c/s sprocket, swingarm pivot bolt & axle bolt all in alignment. That is where the chain is the tightest. Then you adjust the rear axle to get a certain % (don't remember what that is off the top of my head) of free play.

I've had no issues with prematurely wearing out the chain slider on the swingarm.

Do you know if your friend aligned the c/s to swingarm bolt first, and then dealt with the mounts and pipe & airbox positioning last?
Last edited by Tedh98 on 03:27 pm May 04 2011, edited 1 time in total.
market
Member
Posts: 27
Joined: 04:33 am Apr 30 2011
Country:

Post by market »

thank you guys!!!! another question......in your hybrids did you use the kdx or the cr (or kx) silencer? probably the kdx-one qould be better cause it's longer....right?

(as far as i know a longer silencer means a quieter bike and with some torque added in the low-midrange)....am i right?


thank you again and sorry for my bad english!
:partyman:
User avatar
scheckaet
KDXRider.net
KDXRider.net
Posts: 3740
Joined: 12:09 am Nov 10 2005
Country:
Location: edmond oklahoma

Post by scheckaet »

You can't re-use straight up the KDX silencer. I did, but had to modify it heavily to fit (shorten the can 1.5-2 inches to clear swingarm and custom make the tube connecting to the expansion chamber ... lots of $$$ since I don't have a welder)
Most get a stock KX 250 silencer, it usually fits the KDX expansion chamber since the 125 is too small.
Don't know about the cr conversion.
Bad english? where u from?
market
Member
Posts: 27
Joined: 04:33 am Apr 30 2011
Country:

Post by market »

thank you so much!!

i know that the kdx silencer won't fit immediately....but if i use a kdx pipe, why have i to rebuild the tube that connects the silencer to the pipe? it's not enough just to bend it? obvioulsy i think that the mounting holes on the silencer probably have to be rewelded in the right place to match with the frame mounting holes...


by the way.....i'm italian..... :wink:
User avatar
scheckaet
KDXRider.net
KDXRider.net
Posts: 3740
Joined: 12:09 am Nov 10 2005
Country:
Location: edmond oklahoma

Post by scheckaet »

the length and bend are totally different. and yes you'll most likely will have to relocate or fabricate some new mounts (easy).

Italian? your english ain't too bad, I used to live in France over 10 years ago, we were almost neighbors :lol:
chopper
Member
Posts: 31
Joined: 10:55 pm Nov 24 2010
Country:

Post by chopper »

I am using a KDX pipe and silencer on my CR/KDX hybrid,FMF desert/FMF tubine coreII.
hybridracing65
Member
Posts: 63
Joined: 11:15 am Feb 21 2010
Country:

Post by hybridracing65 »

>|<>QBB<
Tedh98 wrote:>|<>QBB<
hybridracing65 wrote: A freind of mine who recently done and 04 KX125 conversion has had trouble with sprocket alignment.
He says the motor a little low and that the chain needs to be run excessivly loose and he is not comfortable with that.
I was wondering if anyone else has had this problem with the kx builds.

I didn't have that problem with the two '04 KX builds I've done. I didn't even bother using the KX chain specs due to having a different engine in the bike. To get the right chain tightness, I followed the procedure where you remove the shock and then rotate the swingarm to get the c/s sprocket, swingarm pivot bolt & axle bolt all in alignment. That is where the chain is the tightest. Then you adjust the rear axle to get a certain % (don't remember what that is off the top of my head) of free play.

I've had no issues with prematurely wearing out the chain slider on the swingarm.

Do you know if your friend aligned the c/s to swingarm bolt first, and then dealt with the mounts and pipe & airbox positioning last?
Yes he set the motor in and used the swingarm bolt but he set the motor in and i think looking at most other things for alignment first such as pipe alignment, headstay clearance, tank clearance.
He has also changed his suspension link tring to get the pegs and gnd clearance higher.
he is getting premature slider wear so he has went so far as to have swingarm bolt hole welded and then relocated the hole and remachined for allignment.
Crazy stuff!

For the later posts about silencers. My pics are old but I ultimately used the kdx knarley pipe and kdx silencer on my CR.
Most guys i know use kx 250 silencers on the kx hybrids.
User avatar
Tedh98
Supporting Member II
Supporting Member II
Posts: 1576
Joined: 01:08 pm Mar 20 2009
Country:
Location: Atlanta, Georgia
Contact:

Post by Tedh98 »

Wow, sounds like your friend truly has a one-of-a-kind hybrid. I'm guessing that suspension link is the biggest single source of his problem. On the two '04's I've done, everything basically fell into place. I only ran into tank clearance problems when I put the oversize tank on.
hybridracing65
Member
Posts: 63
Joined: 11:15 am Feb 21 2010
Country:

Post by hybridracing65 »

>|<>QBB<
Tedh98 wrote:Wow, sounds like your friend truly has a one-of-a-kind hybrid. I'm guessing that suspension link is the biggest single source of his problem. On the two '04's I've done, everything basically fell into place. I only ran into tank clearance problems when I put the oversize tank on.
Well he managed to keep both his head stays and he has had no tank mounting issues and he is running an oversized tank so most of his problem is in engine placement.
Heck he even managed to fit 09 450 rad shrouds! :shock:
i agree with you on the link.
I think thats his main source of chain slider wear.
factoryX
Member
Posts: 352
Joined: 01:33 pm Jan 22 2011
Country:

Post by factoryX »

Note to self, if I do a hybrid, use an 02 and up cr125 chassis...
Image
Post Reply