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Discussion Starter · #1 ·
This is my first post on here, but I figured there aren't many conversions of this magnitude out there. It has been hard finding good info for what I've done so far, so hopefully this will help someone else. And maybe someone on here will have some good advice for me too.

Basic project is this: Titled 76' XT500 frame, 80' TT500 engine, 2001 YZ426F suspension all crammed together.

I've already got most everything fitted together. Yamaha actually kept a lot of things very similar over those 25 years. The swing arm slid right in, and the steering stem was adapted to the YZ tripples with very little effort. The chain even lines up! I've de-raked the frame from the 31ish degrees down to around 27. The YZ subframe has been fitted. I'm using a 4.1 gallon tank for a 82? YZ250. Early 80s YZs had the shock up under the tank so the tunnel was wide enough to fit over the wide XT frame rail. Since this is my first post I don't know how to get the pictures integrated with the text, but one of them you will see is a shot of the stator. I made my own backplate which fits an additional lighting coil. The plan is to have one coil dedicated to the head light, and the other for everything else. Thanks to thunderbike racing, I also learned that you can adapt the electronic ignition from an XR200 to this thing. So far I have the pickup coil mounted. When I get to making that work I'll be sure to post more about it. This weekend I got the 37mm FCR fitted up, and custom made some 1 3/4" stainless exhaust.

I've got two little kids, so my work tends go in spurts as I have time, but I will try to keep this as up to date as I can. I obviously left out a lot of details. If you have questions about how I got things to fit etc. let me know.
 

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Discussion Starter · #6 ·
Here's a shot of the exhaust off the bike. I know it seems crazy to come around the the left side only go back to the right, but I was going for the old HL500 look. Now I just need a tig welder to finish it off. Anyone in the Minneapolis area that wants to lend me one?
Next shot is the right side, obviously. You can see the FCR carb is a tight fit. Everywhere I read said that it wouldn't fit the stock XT frame, but to me "fit" is kind of a loose term. Oh yeah, another thing that hasn't changed in forever, the kick start shaft. The newer YZ kicker fits right on. You can also see down where the points used to be is the XR200 ignition pick up.
 

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Here's a shot of the exhaust off the bike. I know it seems crazy to come around the the left side only go back to the right, but I was going for the old HL500 look. Now I just need a tig welder to finish it off. Anyone in the Minneapolis area that wants to lend me one?
Next shot is the right side, obviously. You can see the FCR carb is a tight fit. Everywhere I read said that it wouldn't fit the stock XT frame, but to me "fit" is kind of a loose term. Oh yeah, another thing that hasn't changed in forever, the kick start shaft. The newer YZ kicker fits right on. You can also see down where the points used to be is the XR200 ignition pick up.
Keep the pics/updates coming! We need more new guys like this :lol:
 

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Discussion Starter · #9 ·
I did look into those fancy ignition setups at one point but they are very expensive. The XR set up is only costing me $80-100. Plus it's more fun to me to have to figure out what will work rather than just pay for something. If I wanted that I should have just picked up a DRZ.

On a carb note, does anyone know much about the fcr carbs? I need to get a picture but on the inlet side there are what look like two small jets near the bottom. These "jets" got air from a separate little passageway going to the air filter. Due to the carb being in a totally different location I can't use the factory YZF air filter boot. Do the jets need to be separate from the main air flow, or can I just use some sort of tube to connect the carb to the filter? And speaking of that tube, I'm looking at a XR400 boot. Would anyone happen to know the inlet bell diameter of the XR400 carb?
 

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thats just plane ol' bad ass! :thumbup:

I love bastardizing Yamahas they kept so many things the same over damn near 30 years!!

I built an SRX6 with FZR forks and wheels a few years ago, did several FZR-YZF upgrades and swaps, seen TONS of r1 and r6 stuff swapped on to RDs and RZs.

I recently passed up on an XT600 project that im really kicking myself for not getting!! I was thinking of doing exactly what you are doing with it.. just to many projects at the moment

Congrats man!!
 

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If you plan on using the YZ airbox.. try moving the carb back from the head as far as possible. Some old guys told me years ago, The further you can get the carb from the head the better on a big single.. I never tried it and im sure there is some math to it, but with the extended pipe you got going, might make since to at least give it a shot.
 

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Discussion Starter · #17 ·
Good call on Sudco. I've been to their web site before, but never paged through their entire catalog which is what you have to do to find carb dimensions. Anyways, the XR400 air boot should fit. Might be a little big, but nothing a hose clamp can't handle. I've got one on order that should be here tomorrow.

Last night I got all of the tank mounts made up. Have pics, but they are still on my phone. I've also been a little preoccupied with a new bike I picked up. Got an old Honda FT500 with a title for $150. I'm thinking street tracker. So yeah, I've been a little ADD and have been figuring out what mods to do to that when this bike is done.

I did get a little work done on a wiring diagram though. It's still missing a few things, mainly ignition. Most of the wire colors are for Trail Tech components. When I get it done, I'll be sure to throw part numbers on it so that anyone could copy the set up.
 

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nice project! i have an old 76 xt 500 also im going for a street tracker thing. nice to know that swing are will work pretty easy.

any more info on the xr200 pick up? points are a bitch in the rain haha
 

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the jets on the carb bell do not need seperate air, I just stuffed a uni filter over the two fcr's ive had works great.

You want the carb as close to the head as possible that way the fuel does not puddle halfway to the head.

Badass build btw.
 
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