Kx500af almost complete, just need ideas on fixing airbox and rear brake spring

[500donk]

Hi, I've almost completed my kx500af. Its a kx500 01 motor in a Kx450f 08 frame. I've bolted the bike together and the only problems I'am battling to fix is the connection between the carbie and the 08 kx450f airbox and the mounting for the rear brake lever spring. Any idea's or advice would appreciated.

[BacK.IN.THE.DaY]

THAT IS A NICE KXAF 500 YOU GOT THERE M8
 
HOW MUCH HAS IT COST YOU ALTOGETHER

NOT INCLUDING THE ENGINE

I WANTED TO TO THIS WITH MY 87 K5 ENGINE

[kxpegger]

I think it's Hammerhead the same rear brake lever you have on your bike that offers a kit that deletes the lever to frame return spring and incorporates the return spring on the master cylinder.

Here's the video from Transworld. He's doing the conversion on a Kawasaki so I think it should work on your frame/master cylinder.

http://motocross.transworld.net/1000104024/features/how-to-presented-by-bikebanditcom-shifter-and-brake-pedal-install/

[sandblaster]

Sweet machine.
I hope mine looks as good 

[bigbellybob]

daaaaaaaaaaaaaaaam Gena! 

[500donk]

THAT IS A NICE KXAF 500 YOU GOT THERE M8
 
HOW MUCH HAS IT COST YOU ALTOGETHER

NOT INCLUDING THE ENGINE

I WANTED TO TO THIS WITH MY 87 K5 ENGINE

Yeah its sweet, it just looks mean! Definately worth the effort to build. Its probably cost around $5,000 to $6,000. Not exactly sure. I should have brought a donor Kx450f instead of buying parts individually. Cant wait to ride it. I've never riden a 500 2 banger before.

[500donk]

I think it's Hammerhead the same rear brake lever you have on your bike that offers a kit that deletes the lever to frame return spring and incorporates the return spring on the master cylinder.

Here's the video from Transworld. He's doing the conversion on a Kawasaki so I think it should work on your frame/master cylinder.

http://motocross.transworld.net/1000104024/features/how-to-presented-by-bikebanditcom-shifter-and-brake-pedal-install/

Thanks mate. I fixed that problem. Just the issue of the airbox now.

[speedywent]

99-02 KX 250 airbox boot. It's only $20 or so from kawasaki and you have to make an adapter plate out of sheet metal to make it work but otherwise fits perfect. I used 2 pieces of .063" aluminum and cut them to fit the airbox. I then figured out the orientation of the boot and cut the metal sheets to accept the boot. I used 2 of them to sandwich the boot flange to ensure no leaks and I used lots of sealant to seal the whole setup and it looks great. Toss the backfire screen as you won't need it on the 2 stroke and it makes air filter cleaning much easier. I've heard that the CR250 boot works also but cannot confirm.

Good luck. I see that you still need to secure the pipe to the subframe also. I'll try to get some pics of mine up for you to show you how I did mine.
The brake spring wasn't an issue for me, I only removed the part of the frame as necessary for the kickstarter and the hole for spring attachment was still there.

Enjoy and don't rush it. I sure love mine. I had this one completed and had a 450 as well until the engine grenaded for the last time. It's 2 stroke big bores for me from now on.

[500donk]

99-02 KX 250 airbox boot. It's only $20 or so from kawasaki and you have to make an adapter plate out of sheet metal to make it work but otherwise fits perfect. I used 2 pieces of .063" aluminum and cut them to fit the airbox. I then figured out the orientation of the boot and cut the metal sheets to accept the boot. I used 2 of them to sandwich the boot flange to ensure no leaks and I used lots of sealant to seal the whole setup and it looks great. Toss the backfire screen as you won't need it on the 2 stroke and it makes air filter cleaning much easier. I've heard that the CR250 boot works also but cannot confirm.

Good luck. I see that you still need to secure the pipe to the subframe also. I'll try to get some pics of mine up for you to show you how I did mine.
The brake spring wasn't an issue for me, I only removed the part of the frame as necessary for the kickstarter and the hole for spring attachment was still there.

Enjoy and don't rush it. I sure love mine. I had this one completed and had a 450 as well until the engine grenaded for the last time. It's 2 stroke big bores for me from now on.

Thanks for that mate. I'll do that and get a kx250 boot. Sounds like it work well on yours. The bike is going into the shop on monday to get the exhaust mounts welded and have the radiator modified and mounts for the coil put in place. The issue with the rear brake spring was I was to stupid to notice the hole to hold the spring where the swing arm bolt is. I've always owned CR's and wasn't familiar with the Kx.

[500donk]

Well I finially finish the mighty Kx500 af and it looks and rides better then I expected. The local motorbike whiz modified and welded up the radiator and the exhaust mounts and it looks as stock as. Fixed the airbox up with the advice of using the Kx250 air boot, and made an alluminium adaptor plate for it to attach to. It was tight but with the aid of some Sika flex it does the job.

I would like to thank everybody at Kxriders.com for there advice and posts. It made things so much easier. I would like to say special thanks to Bempa and his document that he put together on his build. It helped heaps. Here's the pic's!

[kxpegger]

Nice build!

I do see where the cylinder radiator hose appears to be up against the radiator and the sharp edge of the coil laminate. I used some split clear tubing on the rad hose for the coil clearance issue on mine and trimmed the rad hose down at the cylinder about a 1/4 inch to pull it tighter away from the radiator. I have stock Kawi rads though. The other clearance issue was the rad hose rubbing up against the KIPS inspection cover coming off the water pump. The most serious was the rad rub as it was working it's way through the rad core after about a year and the KIPS cover rub was into the hose weave about halfway to a leak!

[500donk]

Nice build!

I do see where the cylinder radiator hose appears to be up against the radiator and the sharp edge of the coil laminate. I used some split clear tubing on the rad hose for the coil clearance issue on mine and trimmed the rad hose down at the cylinder about a 1/4 inch to pull it tighter away from the radiator. I have stock Kawi rads though. The other clearance issue was the rad hose rubbing up against the KIPS inspection cover coming off the water pump. The most serious was the rad rub as it was working it's way through the rad core after about a year and the KIPS cover rub was into the hose weave about halfway to a leak!

Thats something that I'll have to do with the radiator hoses because there from service honda and there not something that you can get off the shelf here in Oz. A few other things have popped up to since I've been riding it. The wiring loom is pretty tort on a few of the connectors, especially one of the connections between the CDI which is mounted in front of the handle bars and the stator. The other night I went to start it and it wouldn't go. Took me a while to figure out that that connection had been bumped loose. The gearbox is a pain in the ass to fill with such low clearance between the cap and the exhaust. I cut the knob off the cap and made it flat, but you have to use pliers to loosen it if it gets a bit tight. I'll get one of my mates to machine a new one up to suit. Does anyone know if one can be used off another model? The kicker too is an issue with it hitting the frame just above where the swing arm bolt goes through the frame. Its taken a few chunks out from a few big kicks.

I was srprise though that I can change the spark plug without removing the tank. It just squeezes out.

[kxpegger]

The CDI on mine is located on the back side (rear facing) of the main front frame spar with about 3/8" clearance from the cylinder head. Plenty of slack in the wiring with this routing on mine.

[livenlife699]

Works Connection makes an oil fill cap that is flush I am encountering the same issue right now with my build, have to take the exhaust completly off to take the oil cap off! Im placing an order today lol

[500donk]

Works Connection makes an oil fill cap that is flush I am encountering the same issue right now with my build, have to take the exhaust completly off to take the oil cap off! Im placing an order today lol

Thanks mate. That helped heaps. I just dont think Works Connection ships to Australia. But I'll look else where on the net. I'll try ebay.