Open Class XR race development and advise

[mick25]

The pommies remove every second head fin so the mud falls out easyer , so makes them run cooler 

[mick25]

I had an 82XR500RC that I did a bit of work to trying to make it a more stable ride and slightly stronger in power.
I did the following;
A complete 82CR250 front end (forks, triples, wheel, brakes) with heavier springs
Had the rear shock rebuilt with a heavier spring made to suit
Special made brake linings for the front and rear (more metallic compound)
Malcolm Smith bigger foot pegs (period pegs)
Higher comp piston
Larger headers
Modified staintune muffler
HRC grind cam (later changed back to std)
Ran the standard reed valves and most other parts were standard.
The bike handled much better in all conditions, braked much better and made stronger and longer power which was very usable.
Great bike you could use almost anywhere.

There you go an optimistic common sense approach with a pot of gold result for effort. Cheers Redrider.
Coincidentally a friend just bought one a few hours ago for a project, I think its a 83xl500?

Another friend just sent me this pic of a twin shock evo


How  is that

I had an 82XR500RC that I did a bit of work to trying to make it a more stable ride and slightly stronger in power.
I did the following;
A complete 82CR250 front end (forks, triples, wheel, brakes) with heavier springs
Had the rear shock rebuilt with a heavier spring made to suit
Special made brake linings for the front and rear (more metallic compound)
Malcolm Smith bigger foot pegs (period pegs)
Higher comp piston
Larger headers
Modified staintune muffler
HRC grind cam (later changed back to std)
Ran the standard reed valves and most other parts were standard.
The bike handled much better in all conditions, braked much better and made stronger and longer power which was very usable.
Great bike you could use almost anywhere.

There you go an optimistic common sense approach with a pot of gold result for effort. Cheers Redrider.
Coincidentally a friend just bought one a few hours ago for a project, I think its a 83xl500?

Another friend just sent me this pic of a twin shock evo


How  is that

One of those English evos , mono shock swingarm mod to twin shock then disc forks to drum ? It's only $6,000 pounds 

[Mick D]

Yeah, but that's better than the original 6000 lbs 

[mick25]

Yeah, but that's better than the original 6000 lbs 

I'm used to the heavy gals , I still can't beleave the bargain fat toy got today 

[Mick D]

The pommies remove every second head fin so the mud falls out easyer , so makes them run cooler 

That makes sense Mick, I met an Irishman today whilst grabing lunch at the local, he was wearing a tee shirt and singlet. He said, "you blokes don't know what cold is. This is like a summer day back home " So that's got me thinking that they don't even need fins over there.

Yeap, more fins, more surface area, more air contact, more work for Pete

[Mick D]

Yeah, but that's better than the original 6000 lbs 

I'm used to the heavy gals , I still can't beleave the bargain fat toy got today 

Yeap, bargain alright

Hey if you like them big girls so much?
How come I hear you been going to so much trouble to trim the Fat Hey

[mick25]

The pommies remove every second head fin so the mud falls out easyer , so makes them run cooler 

That makes sense Mick, I met an Irishman today whilst grabing lunch at the local, he was wearing a tee shirt and singlet. He said, "you blokes don't know what cold is. This is like a summer day back home " So that's got me thinking that they don't even need fins over there.

Yeap, more fins, more surface area, more air contact, more work for Pete


Bloody Irish  funny stuff , the honda boys didn't make very long fins on there heads 83,84 xr500 but they did put that pie oven on the side of the head , maybe take the the door off to let some heat out  . 

[yamaico]

The pommies remove every second head fin so the mud falls out easyer , so makes them run cooler 

That makes sense Mick, I met an Irishman today whilst grabing lunch at the local, he was wearing a tee shirt and singlet. He said, "you blokes don't know what cold is. This is like a summer day back home " So that's got me thinking that they don't even need fins over there.

Yeap, more fins, more surface area, more air contact, more work for Pete

Haha, no problem Mick. Take em off, put em on, up to you

[Hoony]

or you could just go out and ride it 

[Mick D]

or you could just go out and ride it 

Party pooper

Good idea but
But,,,for me, the thread is about making them easier to live with.
Again the 500 is two heavy and a pain to start.
The 350 in full trim is heaps easier to ride, but doesn't have the trill of the massive tearing the knobs off torque.

Lots of ideas, hope I live on for a while.

[Mick D]

One thing I will say about starting the 500, is that it is a very easy bike to clutch start.
Difficult to push, yeah sure. But not down hill

One thing I read on the XR forums was to position the handlebar decomp lever backwards and down a bit so you could squeeze it in with your thumb. So if you do stall it while you still have a little momentum in play? you just grab the clutch lever and thumb around the decomp, let the clutch straight out, engine spins, then let the decomp out a second latter.
Starts really easy. Maybe its just higher crank speed equals bigger spark. Tried it heaps, really easy to start, hot or cold.  Maybe I should check to see if my windings are getting lame. Although only stalled it twice unintentionally, once was when running out of fuel up hill(rolled back down, I landed between two large rocks, bike landed on top, supported by large rocks, lucky) and the other, I would rather forget.

Still needs a massive diet but. 

[Mick D]

Actually there you go, good to brain storm back and forth,
Maybe some times I cant see the forest for the trees thing,

From now on stop on hills and get there early and set up camp on hill, too easy,
90% of starting problem no longer exists

Took me a while to figure that, maybe the Doctor was right after all.

[mick25]

The xr500 84 I had a while back I didn't have starting issues .
Finding top dead centre helps just finding it at times when you are holding a race start up
I have been thinking on my xr500 81 engine trying to make a top dead centre marker off the rev counter bit that runs off the cam for easy starting , I've all ready marked it out and it will work , bit like the little window the tt500,xt500s came out with to find top dead but doesn't really work or needed I have found , nice try Yamaha 

[Mick D]

Yes Mick. I reckon thats my problem with the big Hondas, that I rarely have the crank in the right place when I kick. I had no problem with the Yamies and the DRs were piss easy. I need to put a little window in the XR. And a notch in the end of camshaft.
Cheers.

[80-85 husky]

the big husky is simple.... kick thru till the kick starter stops..pop the decomp and kick it a little bit then let the decomp off and give it what for on the lever...99% success