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Monkeywrench
Monkeywrench Reader
8/29/12 3:37 p.m.

I totally forgot about this forum.

I picked this bike up a year ago for a steal ($1100) I don't know all the details, other than it was built by a Yamaha shop just outside of Reading, PA as a "street legal flat track bike". The kid I bought it from inherited it from his uncle, so all he knows is that it "wheelies and belches fire". It didn't run when I bought it as it needed a coil. Best I can tell is that is has the entire White Brothers treatment in the engine. The rear subframe was chopped and a flat track tail was installed. I've had it for about a year, but I didn't get it running until this past June, which I ran it through the gears hard (a confirmed 103mph, which I'm very happy with from an old single. It was still pulling too) and parked it until recently (full time student, work, other hobbies that were more pressing).

It also has Progressive shocks and springs (f & r). I'm not sure on the wheels. I suspect they're XS650 pieces.

As purchased: Can't get the links to work. Try this ( http://www.flickr.com/photos/52563404@N02/6122050115/ )

Last week I built a new rear subframe (the welding isn't the best, but I'm learning. That's the point of this bike): ( http://www.flickr.com/photos/52563404@N02/7834372244/ )

Also added a muffler that came with the bike:

(http://www.flickr.com/photos/52563404@N02/7889701486/)

It drags however, so I'll need to figure out something else down the road. I'll probably build something like this:

In the meantime, I changed the oil (20-50 Mobil 1 "V-Twin"), added oil lines to the rocker box, and adjusted the valves. They were a little on the tight side, so I opened them up to .008. I don't know the exact cam in this, other than it's either a WB1 or 2. I split the difference on the really aggressive race cams (.010 range) and stock (.005). Works fine. So far I've put about a 100 miles on the bike.

I'm now prepping the body work for paint (yellow with the bumble bee graphics)

Jetting specs for this curious. I tried a 35 pilot jet, but it wasn't happy about that (wouldn't idle down, high idle, felt anemic, etc):

Mikuni: 36 VM

Slide: 3.0

Needle: 6DH3, 3rd (middle) clip on the needle

Needle Jet: P-8

Main Jet: 220

Pilot Jet: 37.5

Air jet: none

Air Screw: 1.3 turns from all the way in.

Idle is rock steady at 1300rpm.

Different than what a lot of others are running, but the plug looks good and the bike feels strong and crisp everywhere. I'm not sure what I'll get for mileage

I still would like a different tank, a rear disc brake, and some more dirt track looking tires. It's rideable work in progress. I don't have a lot of money to put into this, so it's more of a "when I get some extra pocket change" type of project.

pilotbraden
pilotbraden Dork
8/29/12 4:02 p.m.

Mighty nice.

PHeller
PHeller SuperDork
8/30/12 8:20 a.m.

Wish I could see the pics but work filters deem motorcycles too distracting.

stroker
stroker Dork
8/30/12 1:33 p.m.

I hate you.

Monkeywrench
Monkeywrench Reader
8/30/12 4:56 p.m.

Painted: http://www.flickr.com/photos/52563404@N02/7896654958/

I'll let it dry for a few days before wet sanding and applying graphics.

edit: curing on the bike: http://www.flickr.com/photos/52563404@N02/7897141914/

Moparman
Moparman HalfDork
8/30/12 8:25 p.m.

I love thumpers! Good 70s bikes are difficult to find up here in cruiser heaven NEPA. Great find and great work.

CarKid1989
CarKid1989 Dork
8/31/12 6:19 a.m.

Good lord almighty thats a good looking bike. Great stuff

Monkeywrench
Monkeywrench Reader
8/31/12 7:45 a.m.

I'm really happy with the way it is coming out. While not a real flat track bike, it's developing into a supermoto/superbiker/ tt looking bike. I really would like a rear disc and fabricated swing arm, but that is much more money than I have to spend right now. Eventually I'll clean up the instrument cluster

Also, excuse the grammatical errors in my first post.

Old superbiker coverage: http://www.youtube.com/watch?v=ScFlCuBzaks

Monkeywrench
Monkeywrench Reader
9/1/12 7:37 p.m.

With graphics: http://www.flickr.com/photos/52563404@N02/7909872418/

fasted58
fasted58 UltraDork
9/1/12 8:04 p.m.

nicely done

needs hotlink

benjamin666
benjamin666
9/11/12 4:46 p.m.

What rockers are in your sr500? I am building one right now and have a wb-1 cam to install as was wondering if i need hardend rocker arms.

Appleseed
Appleseed PowerDork
9/12/12 4:32 a.m.

The bumble bee stripes rule.

Monkeywrench
Monkeywrench Reader
9/13/12 10:41 p.m.

I honestly am not sure about the rockers. It was built by a Yamaha shop outside of Reading PA, but that was long enough ago that they don't have a build sheet for it. So far, no problems. I'd go with the hardened rockers from Megacycle. Call Mark at Thumperstuff, he should have some.

Monkeywrench
Monkeywrench Reader
12/10/12 9:05 p.m.

A sign of things to come....

http://www.flickr.com/photos/52563404@N02/8263325258/ http://www.flickr.com/photos/52563404@N02/8262286733/

Shortened Radian swing arm, RM250 rear hub and entire disc brake set up, SM Pro Platinum 2.15x19" rear rim. Everything but the rim and spokes came from an AHRMA racer, and he gave me a fantastic deal. I also got a really good deal on the rim and spokes as well.

A new exhaust with a stepped header I spec'ed out in PipeMax is in the works as well. It'll feature a machined exhaust spigot and the works. Pictures to follow in the coming weeks.

N Sperlo
N Sperlo UltimaDork
12/10/12 9:10 p.m.

I don't need to want a bike again. I have too much on my plate.

Monkeywrench
Monkeywrench Reader
1/5/13 7:59 p.m.

Update:

Here is a photo of the work I did to get the rear master to work with the new swing arm: http://www.flickr.com/photos/52563404@N02/8351090045/

Mock up: http://www.flickr.com/photos/52563404@N02/8352156628/

The frame will be painted the same color as the swing arm. It's Eastwood's 'Vintage Racing Wheel Silver Paint'.

I had Full Circle V-Twin (www.fullcirclevtwin.com) make me up an exhaust kit. The co-owner of the shop is a flat track racer himself. He made up the megaphone/reverse cone/muffler, brackets, and the spigot and threw in tubing and all the hardware for me to cut and weld up. I used PipeMax (http://maxracesoftware.com/pipemax36xp2.htm) to figure out my tune lengths. It's a stepped header going from 1.625" od to 1.75" od, before entering the megaphone.

Here is how it turned out: http://www.flickr.com/photos/52563404@N02/8352155098/ ( port matched this to the exhaust port) http://www.flickr.com/photos/52563404@N02/8352155360/ http://www.flickr.com/photos/52563404@N02/8351091043/ http://www.flickr.com/photos/52563404@N02/8351127887/

I'm saving up for tires before I can install the other swing arm and wheel and get it on the ground. All but the muffler can will be ceramic coated black, and like I said, the frame will be the silver you see on the swing arm.

Monkeywrench
Monkeywrench Reader
1/19/13 4:38 p.m.

It's mostly back together: http://www.flickr.com/photos/52563404@N02/8396666952/in/photostream

stroker
stroker Dork
1/19/13 6:28 p.m.
Monkeywrench wrote: It's mostly back together: http://www.flickr.com/photos/52563404@N02/8396666952/in/photostream

I hate you more.

Monkeywrench
Monkeywrench Reader
2/17/13 7:03 p.m.

Not much to update. Got the exhaust tig welded - still have to send it out. It'll either go to Swaintech or Zirocotec. Waiting for some #240 bend flat track bars to come in, I have a new throttle tube, grips, and clutch perch / lever to go along with it. Still need to fit up a chain and make wheel spacers. I worked on the electrics a bit. It's mostly done. I made a soft mount for the electronics. They're insulated to the plate along with the plate being soft mounted. It also gets everything from under the seat and into some air. I have to fix the capacitor mount - it'll look better when I do.

GregWClassic
GregWClassic New Reader
2/21/13 1:35 p.m.

That is a very clean bike. Nothing that is not needed. Nice job.

Mitchell
Mitchell SuperDork
2/21/13 2:03 p.m.

Very nice! That would make a great hooligan bike.

Monkeywrench
Monkeywrench Reader
2/22/13 10:28 p.m.

Thanks, guys! I'm really stoked how it's coming out. I can't wait to ride it again.

44Dwarf
44Dwarf SuperDork
2/23/13 4:09 a.m.

Nice job! Say what did you do with the cast mags? Were they 19 inch front and rear? If you still got'em shoot me a PM.

Monkeywrench
Monkeywrench Reader
2/25/13 8:19 p.m.

Ah, the bike pictured isn't my bike. I actually think it's in Europe somewhere. My bike had aftermarket shouldered rims front and rear (18" rear with a drum XS650 hub). I changed over to a RM250 hub so I could run a rear disc and had a 19" rim laced to the rear. The front is the same. The entire rear end was off a XS650 and would prefer to sell that as a package.

Monkeywrench
Monkeywrench Reader
3/19/13 8:19 p.m.

Exhaust is back form H.M. Elliott. New handle bars fitted. Just waiting for wheel spacers, a chain, and new cables to come in. Here is the exhaust mocked up:

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