Suzuki Central Forum banner

1 - 20 of 58 Posts

·
Registered
Joined
·
839 Posts
Discussion Starter #1
After 3 years of owning this machine I finally have decided to rebuild this XC 2003 KFX 400 as the mx quad of my dreams. (Hopefully this build doesn't take 3 years lol)

I picked this up from a member on here who owned it since day one, raced it a couple seasons and it sat in storage since 2005. The thing was meticulously maintained, came with all stock parts, and all original receipts.

Unfortunately before he sold it the motor overheated and it was found to have very tiny metal shavings in the oil filter which makes me assume something went bad in the bottom end. I haven't decided what I should do with the motor, keep the motor all Yoshimura or go a different route. I know these motors put out massive power back in the day. Its set up with the Yoshimura 449 stroker kit, with piston, crank, gasket, Web cams, Kibble white valves and springs.

I plan on taking the quad to the local mx practice track and running it on the ice in the winter. With this thread I hope to get some ideas, ask some questions, and share this with all of you. Enjoy!
 

Attachments

·
Registered
Joined
·
2,225 Posts
sweet little thing, document the whole rebuild it would be fun to watch this one.


nice shop btw.
 

·
Registered
Joined
·
839 Posts
Discussion Starter #4
what is you plan for suspension? i would recommend a steering stabilizer if you dont already have one.
I have a set of 2009 Roll LOBO II +3+1 a arms I picked up from Deuce on here. To make them fit my 03 I have to use 05+ steering stem, 09 spindles, and 09 tie rod ends - I have everything but the tie rod ends.

I picked up Long Travel Elka Stage 4's all around in February when they had that killer deal.

And for the rear I have a LSR +1 or 1.5+" swing arm, elka link, all new carrier, pivot, and suspension bearings, along with a RPM domminator +1 to +4 axle.

As for the stabilizer I have one. Its a low mount made by W.E.R. and is adjustable. I would like to use it but they changed the bottom of the stems in 2005. So I don't know if I can use the same mount, or if W.E.R. has a way to mount it to 05+ stems
 

Attachments

·
Premium Member
Joined
·
4,280 Posts
the extended swinger coupled with the forward arms will make it a little hard to turn, but it will help on the holeshot. with a long wheelbase like that youll really notice it on a tight supercross style track.

i love my LT elkas, i have them front and rear and i have no plans to change them. the customer support and parts availability is awesome too, which is a major bonus for me.

did you gusset the frame yet?
 

·
Registered
Joined
·
839 Posts
Discussion Starter #6
the extended swinger coupled with the forward arms will make it a little hard to turn, but it will help on the holeshot. with a long wheelbase like that youll really notice it on a tight supercross style track.

i love my LT elkas, i have them front and rear and i have no plans to change them. the customer support and parts availability is awesome too, which is a major bonus for me.

did you gusset the frame yet?

I never really thought length would be an issue since most MX quads I have seen from back in the day had longer swing arms and +1 forward. I am modeling this after a national quad and I am probably not gonna be on any technical or tight tracks so I should be fine.

The frame is already gusseted, not sure what kit it is, but I was told it was done by the Kawasaki dealer. It hits all of the key points and has more gussets than the Bare Performance kit. Gonna send it out to powder coating sometime this month.
 

·
Registered
Joined
·
839 Posts
Discussion Starter #7 (Edited)
Update.

I am now going through the motor and looking for any serious issues. Again the bike overheated and it was shut off immediately. There were tiny aluminum pieces of metal in the oil filter looking like glitter. I took the side case off by the clutch expecting to find metal down there and did not find anything out of the ordinary. Is it safe to assume that the aluminum shavings are from the piston rings? Or would this be early signs of crank bearing failure?

I pulled the cams out, initially disappointed because they looked like stock cams. I was able to read WEB etched on them with their grind numbers so that was a relief. I am going to pull the entire head off this weekend to see if the piston scratched the walls of the cylinder.
 

·
Registered
Joined
·
839 Posts
Discussion Starter #8
Yep, found some bad news. The piston scratched the cylinder walls and the motor is shot. I reached out to Yoshimura and parts are no longer available other than the Yoshimura head gasket. The guy I spoke with just told me "maybe its time for you to look for a later model machine?". Lol last I checked they made this quad as of last year, though due to the lack of demand they discontinued this kit and availability of parts have dried up. Trying to figure out what my options are here below:

Rebuild the yoshi motor:
-Buy a new 5+ yoshimura crank from a race shop that I know has a couple left.

-Have the cylinder re-coated by millennium technologies

-Buy the yoshimura head gasket (grab an extra for down the road)

-Have the piston copied (a regular 92mm won't work because it has to have the same location for the wrist pin for the stroker kit, otherwise you will have some clearance problems.)

OR go with a complete new kit? 470 stroker or something comparable, maybe max power?

The yoshimura guy even told me this.. "I'd very careful with other company's big bore an stroker kits. Heard so much bad things like not lasting an blowing up." - I have an idea of what is good and what to avoid. I know there are reliable kits out there if I went in this direction.
 

Attachments

·
Super Moderator
Joined
·
3,363 Posts
That sucks. I think you would be farther ahead to just do a 470 kit, pistons, cranks and gaskets are plenty, and you aren't going to lose power. Unless you are limited to a 450 cc class, that's a different story..
 

·
Registered
Joined
·
839 Posts
Discussion Starter #10
That sucks. I think you would be farther ahead to just do a 470 kit, pistons, cranks and gaskets are plenty, and you aren't going to lose power. Unless you are limited to a 450 cc class, that's a different story..
I think I am gonna go the 470 route on this :smile2:


Still working on the build guys! Just have been busy because I recently moved, and had to temporarily relocate my machines and parts. Though it hasn't stopped me from gathering parts! The frame has not made it to the powdercoater but I have decided to do a textured black look. The scheme is going to be textured black, chrome, and carbon fiber.

I just picked up this Chrome Lonestar sub frame made of chome moly tubing.


I also scored a Looney Tuned Dual Exhaust locally. I couldn't pass it up, and decided to get it just for the bling factor. I am gonna start looking some ceramic coating price quotes for the pipes.

 

·
Registered
Joined
·
601 Posts
Ok, I'll bite and ask the stupid question. How are you planning on keeping the rear shock cool enough or properly routing the reservoir line with a dual exhaust setup? Maybe I just can't picture how the pipes get run to the other side.
 

·
Super Moderator
Joined
·
3,363 Posts

·
Registered
Joined
·
839 Posts
Discussion Starter #13 (Edited)
Ok, I'll bite and ask the stupid question. How are you planning on keeping the rear shock cool enough or properly routing the reservoir line with a dual exhaust setup? Maybe I just can't picture how the pipes get run to the other side.
When I ordered my stage 4 package from Elka this past spring I specifically asked for the longer line. They said it was not an option, and provided the short line for the rear sub frame. I reached out to Hygear and they are can install a new longer line on it so the reservoir mounts up front.

Here is how it mounts. looks pretty tight, also I wonder if the heat of the pipe could affect the wiring harness.

 

·
Registered
Joined
·
601 Posts
My older Elka had the long line and it ran right out between the frame and carb where you'll have exhaust pipe in the way. Your kind of limited by the angle of the fitting threaded in to the shock to keep from kinking the hose, so maybe you can have them angle yours a different way than the factory 90 degrees to the side. Straight up may let you poke the line up over the carb and run inside the upper frame rails.

I know my wiring harness would be right in the way too, but its a mess and really needs to be cleaned up this winter, so that may not mean much.
 

·
Registered
Joined
·
839 Posts
Discussion Starter #15
Update 9/12/16!!!

This build is a work in progress but I decided to move forward and keep the yoshimura motor. I was able to find a complete kit with low hours and picked it up recently. It came with a ESR intake system, I think this would be a excellent set up though I definitely would want to make a custom splash guard for it. I will need new piston rings, crank bearings, and a gasket set in order to get this motor kit going.



yoshi cams


intake setup
 

·
Registered
Joined
·
839 Posts
Discussion Starter #16 (Edited)
Update 2/21/17

Yesterday I just dropped of my headers, Edlebrock head-stay, and head cover off at the powdercoater to be ceramic coated with Chromex. I decided not to go with the stainless steal bolt kit. Instead I gathered up my bolts, plus some extras and getting some quotes locally to be zinc coated.

My frame and swing arm have been powder-coated textured black and came out really nice. I finally got all the parts I need for my front end and picked up some 09 spindles and tie-rod ends. All I need to do now is send my shocks out to Hygear, have them install a 4ft reservoir line, change my front red springs to black, and add on some Elka shock guards to them. Once I get the shocks back I should be set to make it a roller!!!



 

·
Premium Member
Joined
·
4,888 Posts
is that the + 5 crank ?
 

·
Registered
Joined
·
839 Posts
Discussion Starter #18

·
Premium Member
Joined
·
4,888 Posts
the cams don't look to be adjustable ,
 

·
Premium Member
Joined
·
4,888 Posts
hello
 
1 - 20 of 58 Posts
Top