I Need 1979 xr500 info! Pic.

[juice_bruce]

My buddy gave me his '79 XR500R, he didn't want it in his garage anymore.

It has 3000 km on it, I haven't washed it but it's pretty clean, by looking at wear points such as, the frame around the foot pegs, the motor casing etc. it looks like 3000 Km may be actual mileage.

My buddy hasn't riden her in a couple years, she has fresh synthetic oil, he had her running in the summer and she was smoking a lot, I'm thinking rings! I'll get a new piston too.
I noticed fresh oil around the top of the head, plug area, perhaps a gasket?

Anyway, I've got to get a service manual, ideally I'd like to download one, this way I have it immediately, no problem paying for it. Anyone know where?

Anyone know what plug it uses?
It has a DR8ES-L in it now, is that correct?

After-market (K&N) air filter, K&N site doesn't list one. Any recommendations?

The carb looks new, need the jetting for an after-market air filter.
I've got the air filter box off and the carb looks clean/new inside, I'm going to pull it off and go through it anyway.

Any recommendations for an after-market exhaust?
Because of the shocks I may have difficulty finding one, might have to customize a mid-pipe?

I also need fork oil weight and quantity per leg.

In the future I might put a 21" front wheel w/disk brake.
But in the meantime just want to get her running and see how she go's.

Thanks,
Bruce

 

[2 strokes for life]

Fist off, buy a manuel. It will save you time posting here. Clymer makes a good one for that bike. As for the air filter i would go with a Twin Air filter because cleaning is easier. As for an exhaust i can not find one for it.

 

[juice_bruce]

Ya I'll buy one, but I'll have to order it and it'll take several days to get!
In the meantime I just want some quick answers so I can get her running and see how she go's.
Also, if anyone has any tips/tricks (from there experience with this XR500) they can pass my way.
The Twin Air Filter, is that the foam inter and outer?
Thanks,

 

[2 strokes for life]

juice_bruce, yes it is. You can clean the foam filters in your sink with a product called No-toil witch is a bio-degradeble filter cleaner that even smells good.

 

[juice_bruce]

I replaced the plug, fresh fuel, and pulled the float bowl off, it was clean, no varnish etc.
With the filter/box off I kicked it over about 20 times and she started. Warmed her up and she ran OK.

However, when I got on the throttle, gas mist would blow out the carb intake!
Fuel would also collect in droplets.

Would the valves be off?
Or wrong jetting?

Any idea's?
Thanks,
Bruce

 

[2 strokes for life]

I would say a worn cam is not opening the valves at the right time, valves are worn, timming could also be a factor. Once you get your manule put the valves into spec and see what happens.

 

[juice_bruce]

Cool, thanks.
I'll check that out and post with results.

 

[2strokerfun]

I replaced the plug, fresh fuel, and pulled the float bowl off, it was clean, no varnish etc.

While that's good, it still doesn't insure a jet or jets isn't gummed up or clogged with something. Did you remove the jets and clean them??

 

[juice_bruce]

While that's good, it still doesn't insure a jet or jets isn't gummed up or clogged with something. Did you remove the jets and clean them??

No, I got lazy.
I'll wait till I get a service manual (bought one off ebay) so I can find out what the stock jets are. I've heard guys go to a larger main, I may do the same.
I'll also find out what the float height is before I get right into her!
The way fuel was spraying out of her, I'm leaning to a valve issue or timing.
Thanks,

 

[baja92]

i raced one of these

they where a good bike in there day a lot of low end torc, 21 front wheel was not very good, gear boxes where a little weak if you put performance parts on .
but on the whole a very enjoyable bike to ride

forgot to say the main thing to watch is how much wear there is in the camshaft bearings in the head they are part of the head and if they wear badly worn you will have to find a good machine shop to fit some bronze bushes.

 

[firehawkmph]

I used to have and race an xr 500 back when they were new. I had a white brothers pipe on it, which came with a super trapp silencer. Honda also made a factory hop-up kit, which if I remember right consisted of a higher compression piston, hotter cam, and some carb jets. I also installed a set of fox air shocks and air caps for the front forks. The bike was very torquey, always got the hole shot and was very reliable. I applied for a title and actually plated it and rode it some on the street. You could crack the throttle in 3rd and ride wheelies for awhile. Good luck,
Mike

 

[juice_bruce]

Thanks.
Got a Clymer manual.
Changed the fork oil with 202ml of 10w.
Checked the valves, they're good, idles good low rpm is good, mid-range to high runs like crap, sputters and boggs with a bit of black smoke.
I'm going to lean out the needle 1 step but I don't think that will make a difference.
Any idea's?

 

[juice_bruce]

Pulled the carb off, it was pretty clean but cleaned it outanyway, checked the float and it was off 3mm.
So put her back together and she's running nice.
I need to get a new aftermarket pipe, any recommendations?

 

[2 strokes for life]

I have not found any pipes for that bike at all. Its good to know its running.

 

[juice_bruce]

I think I'll watch ebay, find something used off a 450 or similar and have someone make a mid-pipe to join the can to the header.

 

[OnAnySunday]

I know we're probably not supposed to post ebay links.....
But in my search for a xl500r cyl head i ran across this.
http://cgi.ebay.com/ebaymotors/MUGE...190252097QQcmdZViewItem?hash=item130190252097
Looks like its right up your alley.
Hope its what your looking for!

Keep 'em runnin'! :ride:

OAS

 

[juice_bruce]

Cool, looks in decent shape, I'm gonna send him a message, see what his reserve is.
Thanks, I appreciate it.
Bruce

 

[2strokerfun]

If I had your bike, I'd jump on that exhaust. You might never see one like it again.
Good luck!!

 

[juice_bruce]

I recieved a message back with the reserve price, he wants $100 + shipping to Canada which would be about $40.
I'll watch it, see what happens.

 

[2strokerfun]

That's a great price, in my opinion (if someone doesn't bid it even higher to the point of ridiculousness)

 

[wileyE]

Based on the info you posted (or lack of). I wouldn't write the head/cams off just because it smoked a little at start up after sitting for years. Also a little spit back through the carb is normal and called reversion, especially if your watching it without the filter or box. I say little though. The intakes valves may be tight, the float level high or float valve sticking.

In the day those things trucked, I had open two strokes (400 430 490) and my buds xr500 could usually run me in a drag race. Not because they had more hp, because what they had found the ground. The 23" rim is a novelty, I'd leave it (if you can find tires.

 

[juice_bruce]

Disregard me replacing cam's anytime soon, unless I come accross aftermarket cam's somewhere.
She's running decent now, it was the carb, (always check the simple things first) the float was off by about 3mm.
Checked the valves, they're good (peice of mind, I had to check the valves).
Maybe I will leave the 23" wheel, I'll decide that after putting some miles on it, true 23" tires may be an issue, I'll look into that down the road.
Thanks,