Tim's SR500

[Tim]

Today's the official start date (Oct 30 2010) of my project.

I bought the bike a long time ago (year or so?) but it hasn't been in my hands or garage since I bought it. Today with the help of the one and only Mr Dutra (Paul) of Back Alley Motorcycles the SR500 is safe and sound in my garage.

As history tends to repeat itself, and as humans are creatures of habit, the first thing I did was take the tank off and test fit the RD60 tank I picked up at the Barber Festival a few weeks back. Not sure it's gonna fit well, and there is a thin area of the tank with one hole in it in the tunnel area. May not be worth fixing.

But, the fun is beginning!

Plans are for 19" wheels front and back either spoke or mag converting a front 19" wheel to the rear hopefully using one of Omar's DTR 19" wheel conversion kits. Might put Fasst Co. Flexx bars on it, some nice modern rubber with an aggressive tread (19" is tough to get though outside true dirt track tires), flat simple seat, small tank...

I have a nice little 5" headlight already (another Barber find) and an exhaust with a Supertrapp muffler on it. So I'm well on my way.

Some pics of when I got it (blurry dark garage pics), today in my garage with the RD tank and a couple inspiration shots.

 

[stik70]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

this should be a super cool project to follow. Love those thumpers...
kev

 

[Tim]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

The inspiration shots:

 

[pacomotorstuff]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

Tim,
Great start to a great project. If it turns out half as good as your 650, it'll be the bomb!
Back (wwwaaaaaaaaaaay baaaaaaaaaaack!) in the day, when the SR500's first came out, there were a couple of them dirt tracked and ice raced using essentially the stock frame - a lot heavier than a Knight or Panther or Starracer frame, but serviceable enough if you were a Junior-class rider or just too broke to afford anything else...
Getting a tank to fit over that big round hump of the frame backbone / oiltank was always a hassle back then and is now. I think a lot of the guys who raced them used the stocker (can't remember, been too long). Omar has a tank, maybe Airtech and probably others. I started on a project - putting big tunnels in XR750 Harley tanks - for a bike shop that went out of business about the time the job was half finished and never did anything further with it - nor got paid for it, either. If you want to borrow an XR tank top to see how you like the fit and look, let me know.
I'll pass the question re: tanks around to a few old dirt track dinosaurs I know and see if they can shed any light on the tanks used back in the day
As a shameless plug for myself, I make 4 or 5 different dirt track seats which could be used on your bike, depending on how - and what - you plan to do to the frame aft of the shock mounts, what tank you end up with, the look you want, etc etc.
Anyway, if you want some REAL 19" dirt track wheels, front and back, I'm breaking an old dirt tracker for spares. The bike was used as a dirt track / TT bike, so it has a front disc brake combo already sorted out (but no speedo drive, though).
The back wheel I have has the quick detachable hub with a disc. I can't remember what # teeth sprocket is on it, but you can get them from the Azusa dealer in Upper State New York and have the correct bolt pattern machined (what I did on my XV920 Cafe bike).
If you need / want it, you can look at taking the rear master cylinder, brake pedal, linkage etc, as well.
The wheels have seen their fair share of use, are USED, not virginal, but have some real history behind them. In my case, they were kind of destined for my RD350 street tracker which has morphed into a cafe bike with full fairing due to the DTT post re: fairings...
In my case, I was torn between leaving the wheels pretty much as-is and running the "fresh from the track" look or taking them apart and making them look better than new. They'll need new rubber, but the old dirt track tires are mounted, so you can trial fit everything and get a good idea what it'll look like.
If you're interested in any of the above, you have first dibs on the wheels, etc. If anyone else is interested in them, like I said, Tim has dibs.
You can get me at 905-873-3171 or pacomotorstuff@cogeco.ca
Regards,
Pat Cowan,
Vintage Motorcycle Fiberglass,
Pacomotorstuff

 

[Tim]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

Well shoot Pat... you always seem to have something I need (or want). Hit me with pics and price etc for the wheels. If I'm gonna do it up right, I'm gonna do it up right

 

[pawn]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

i hope you get that rd tank on there. I love those! I really want a SR 500 as well. In for this...looking forward to the progress.

 

[VonYinzer]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

Right on Tim. Looking forward to seeing this one.

 

[Tim]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

The RD tank is a bit of a hit/miss thing. Might be a bit narrow at the back end of things. We'll see. And like I say, the walls might be too thin to make it worth repairing - might end up as a garage ornament.

 

[locOleoN]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

Geezz.. its about freakin time man!!...
The SR500 is an awesome bike.. however, there are a few things that you need to know about that 78 model..

1. the fuel pump on that bike it terrible. Your 78 sr500E has a 3 screw pump.. try to find a 5 screw pump that came in the 1980+models.
- The those pumps tend to loose oil pressure, (the 2 plates that make up the pump body is held together by metal dowels) and oil seeps down between the 2 plates and oilseal down into the sump... (current problem my sr500 has...)

2. the stock metal oil pipe does not pump enough oil into the heads. Oil currently travels from the pump through the skinny pipe and up into the intake cam then eventually to the exhaust cam. There is a dual line kit that you can get that delivers oil to both the exhaust & intake cams as the same time and at a greater volume:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230544535637&ssPageName=STRK:MEWAX:VRI

With the weak pump + poor oil delivery to the top end, the Sr500 models up to 79 are known to blow its top end...

3. The ignition modules are known to be faulty. I upgraded to the Hyperpak, ( havent put it in yet... waiting for my 5 screw oil pump to come in...):
http://cgi.ebay.com/ebaymotors/YAMAHA-XT250-XT-250-SR500-SR-500-XT500-XT-500-IGNITION-_W0QQcmdZViewItemQQhashZitem2eb0dfdde6QQitemZ200535956966QQptZMotorcyclesQ5fPartsQ5fAccessories

but I also hear that the Rex Cdi is also really good:
http://cgi.ebay.com/Yamaha-SR500-SR400-XT500-Ignition-CDi-Unit-XT-SR-500-/190463049653?pt=UK_Motorcycle_Parts&hash=item2c587b7fb5

I have a brand new battery for my sr... but I just recently put in a Daytona battery eliminiator on my bike, so you are free to borrow my spare battery if you wish... I
I also have a template for for the electrical plate under the seat, that you can use to cut from a metal sign...

one last thing, get to know Mark Aplan at Thumperstuff:
http://www.thumperstuff.com/
1 360-563-0376

He has all the parts you'll need!!

oh btw.. I have a spare rear hoop from an xs650 if you want.. the sr500 rear frame is such an abortion... sr500 guys like to weld the xs650 rear hoop to the back of the sr500...

 

[Tim]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

Thx for the links and upgrade info - we'll see what bits I end up using on this one.

Pat's hooking me up with true to life dirt tracker wheels - well loved racing wheels - the real deal

 

[boingk]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

Good stuff Tim, be interesting to see how this one goes.

BTW, I think I've got a magazine article detailing how one fellow pumped his engine up to about 50hp... although it might've been an XT500. Either way, I'll give you a yell if I find it.

CHeers - boingk

 

[scm]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

Hi Tim!

Nice bike, nice project!

Concerning fuel tanks: XT500-frames have the same backbone as
SR500s', hence any tank that fits an XT fits an SR too (apart from the
brackets).

OEM XT500 tanks are a bit smaller so might better suit your demands.

To give you an idea, here's a picture of the XT tank on my whatevertracka:

http://galerie.sr500.de/albums/userpics/10006/0808.jpg

looks bigger than it actually is, a good paintjob would give it a slicker
appearance...


Good luck!

Best regards
Sven

 

[Tim]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

We'll see how things go - an XT500 tank may be in my future. Should have an update to post tomorrow sometime

 

[boingk]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

Righteo, the build I mentioned before is British and is an amalgam of an XT500 engine in a TT500 frame, with 10mm lengthened swingarm and CCM forks shortened to suit. Its running Excel rims front and rear to allow 120/70R17 and 160/60R17 tyres for the front and rear, respectively. Here are the crude details:

Capacity: 540cc
BoreXstroke: 90 x 83.5mm
Comp R: 13:1
Induction: 38mm Mikuni VM
Ignition: Power Dynamo digital, customised curve.
Max Power: 50bhp @ 7250rpm
Max Torque: 36ft/lb @ 5000rpm

That sounds simple enough but its running a reworked SR500 crank with a shortened stroke, holding a lightweight Carillo rod and a JE piston. The valves have been oversized by 1mm, and are seated in bronze guides, controlled by tungsten rockers and a custom-designed Newman race cam. Cam is mounted in an SR400 rocker cover (due to it being developed more by the Japanese home market). Headwork has been done (no specifics) to up the compression from 9:1 to 13:1, and the exhaust is a homebuilt affair with a large downtube flowing into an open-mega style arrangement with baffling to suit. It is running an oversized SR500 clutch basket in magnesium casings, and the chassis is from a TT500 with extra gusseting and CCM upside-down fork that have been shortened about 4 inches. 10mm has been added in the swingarm to help stop mad wheelies.

Thats the lot of it, the rest goes on about cosmetics and minor build details. Happy to throw up a picture sometime it you want.

Cheers - boingk

 

[Tim]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

Pics would be awesome - can't see me digging into the engine that much, as this will be a street bike and not really worth investing that much into the engine to shave 0.5 seconds off my run to the coffee shop.

But pics are always inspiring! Sounds like a neat looking bike.

 

[locOleoN]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

can't see me digging into the engine that much, as this will be a street bike and not really worth investing that much into the engine to shave 0.5 seconds off my run to the coffee shop.

... you say that now!!.. wait till you actually ride that thing... its TERRIBLE past the acceleration curve!!... You'll hit the 7-8000 rpm so fast and you'll be thinking "theres gotta be another gear here somewhere.. I cant be on 5th already!!"... as DrJ whips by you on his little 50cc Ascot thinggy...

you'll find that unless you do lots of mods, the Sr500 is gutless. I think youll come back to boingk's post wondering what he did again to his bike!!..

this bike is truly a love/hate relationship... you'll just Love to hate this bike, yet Hate to love it...

Your xs650 will feel like a Honda Rc-51 compared to your SR... and knowing you Tim, you'll tear into the motor... I got $150 riding on that bet...

 

[Tim]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

Har har. I'll need that rear hoop - took the seat off and yeah, it's an abomination back there.

 

[Tim]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

I knew I kept this modified FZR600 swingarm around for a reason. It's been modified to fit an XS650 so it should bolt right into the SR, and it holds the massive 7.5 inch wide rear tire Not sure my new rubber will be so wide, but its nice to know it can handle it (provided I can align the sprockets).

So we have swingarm, wheels, exhaust, number plates... need to finalize a tank and get crackin on putting the bits on.

 

[VonYinzer]

Re: Tim's SR500 - Nov 2 2010 - wheels!

Awesome stuff so far Tim. That swinger wheel combo will really set it apart.

 

[locOleoN]

Re: Tim's SR500 kinda tracker kinda whatever undecided who knows project

Har har. I'll need that rear hoop - took the seat off and yeah, it's an abomination back there.

well come by and pick it up anytime.. just sittin here in the Man-room...
If you are not gonna use that stock seat, let me have it!!..