Paging Kurlon - XR100R

[Garandman]

FWIW, I'm pretty sure that plug was changed less than 10 hours ago.

[breakdirt916]

okay, then still worth checking spark (hot and cold) by grounding the plug and kicking it over to check for spark/rough test of coils...then check float and jets...also the idle speed screw (make sure the "idle speed" isn't being controlled by the slide/main jet) is low enough...then I'd say grab some coils from the bay of fleas

[loudbeard]

Great, thanks for the input guys. I'm out of town for a wedding this weekend but I'll try and get it figured out next week. Can't have my first race weekend go down without a pit bike!

[loudbeard]

Bringing this back from the dead.

Tore down the top end with Degsy last week. The bore looked pretty good but the rings were fairly shot. Turns out (I'll get nomenclature wrong) the air mixture jet(?) Had the washer and gasket in the wrong order and the gasket had fallen off. Anyway, located the source of why its really running like crap.

I found a complete 120 kit for $119 online, which seems to be about 1/2 of what they cost, so I ordered it. I figure I can get that and a pipe for under 300, then jet the carb properly. Logic is if it makes 6 horsepower before, and it makes 6.25 after, that's a pretty nice % increase

Really, the jug just looked like crap on the exterior. Bent cooling fins, bad spray bomb job.

More decisions. I'll be running it up in Winchendon for starters, so o need to decide on wheels. If all I do is flat track, seems to be generally accepted that I can stay on the stock 19/16 and run trail wings. That said, I may be interested in running it at boxshop later on so swapping to the 16" front right away keeps me from buying tires twice.

Things are starting to add up a bit, as I'm looking at another $200 to put some adult sized springs in there.

[Kurlon]

The CAMMRA/Herrin Compound guys have interesting ideas on XR100 suspension, I think the general mantra is heavy oil, stock springs to keep it from chattering.

[Pigman]

I have a Ultrasonic cleaner here at work.........if you need

[nhbubba]

I was told to buy a BBR spring for the rear, use the stock springs but crank up the preload (big spacer) in the front and run 80w oil.

[TheIglu]

Bringing this back from the dead.

Tore down the top end with Degsy last week. The bore looked pretty good but the rings were fairly shot. Turns out (I'll get nomenclature wrong) the air mixture jet(?) Had the washer and gasket in the wrong order and the gasket had fallen off. Anyway, located the source of why its really running like crap.

I found a complete 120 kit for $119 online, which seems to be about 1/2 of what they cost, so I ordered it. I figure I can get that and a pipe for under 300, then jet the carb properly. Logic is if it makes 6 horsepower before, and it makes 6.25 after, that's a pretty nice % increase

Really, the jug just looked like crap on the exterior. Bent cooling fins, bad spray bomb job.

More decisions. I'll be running it up in Winchendon for starters, so o need to decide on wheels. If all I do is flat track, seems to be generally accepted that I can stay on the stock 19/16 and run trail wings. That said, I may be interested in running it at boxshop later on so swapping to the 16" front right away keeps me from buying tires twice.

Things are starting to add up a bit, as I'm looking at another $200 to put some adult sized springs in there.

Can I give it a rip at Wachusett when you get it going?

I'll toss some spend your way to help offset costs of you buying crap, or beer, or both. I just wanna try out the go-round style track riding before buying a bike.

[cdovego]

CMP will be rolling deep into WVRC -

[loudbeard]

Can I give it a rip at Wachusett when you get it going?

I'll toss some spend your way to help offset costs of you buying crap, or beer, or both. I just wanna try out the go-round style track riding before buying a bike.

Of course. When I finish getting it together I think the first step is to do one of the "family days" up there. Looks to be pretty much open practice and there's quite a few days upcoming on their calendar.



Per the suspension, I guess I see doing the springs as a "why not?" type of item. I have to take it apart anyway to change the oil, may as well put in something appropriate for a full grown man. At 6'3" 220 pounds I'm not entirely convinced just going to a heavier fork oil and increasing preload is going to fill all the needs.

[TheIglu]

Just let me know when you go. I pass by the place every day on my way to/from work. It's only 15 minutes from my house.

[cdovego]

I'll be there on the 24th, have a place to stay 20 mins away if need be.

[loudbeard]

Oh, fwiw, here's the linky to the 120 kit I got.
BBR 120cc Big Bore Piston Kit

everything seems to be there, not sure why its half the price as the exact same kit from other vendors, but I'm not arguing right now.

I'll post up when I get things back together and update when I head to Wachusett. Looks like the 24th is the target day, if all parts come in I'll be there. Braaap.

Also, on a technical note. Literally every bolt on an XR100 is a 10 mm. It's amazing.

[Kurlon]

Per the suspension, I guess I see doing the springs as a "why not?" type of item. I have to take it apart anyway to change the oil, may as well put in something appropriate for a full grown man. At 6'3" 220 pounds I'm not entirely convinced just going to a heavier fork oil and increasing preload is going to fill all the needs.

Just passing on what the CAMMRA/Herring Compound crew have determined. My impression is there just isn't enough damping in the world even if you load the forks with tar to keep up with higher than stock spring rates when road racing these little machines. Stiff springs == chatter in the corners 'cording to that crew.

[Garandman]

Bringing this back from the dead.

Tore down the top end with Degsy last week. The bore looked pretty good but the rings were fairly shot. Turns out (I'll get nomenclature wrong) the air mixture jet(?) Had the washer and gasket in the wrong order and the gasket had fallen off. Anyway, located the source of why its really running like crap. //

That may have been my fault. I cleaned the carb in an ultrasonic cleaner. Looks like I didn't assemble it correctly, although it ran OK for most of the season. It never liked to idle except on the intermediate choke setting.

Was pretty sure the rings were bad because 1. it was a 1994 that had passed through several of you (I bought it from Ted Duncan) and 2. It puffed a little blue smoke when started, although it seemed to go away after it warmed up.

"There's no replacement for displacement" so the 120 kit sounds cool.

[Mr. Kurtz]

I'll be there on the 24th, have a place to stay 20 mins away if need be.

Your place? Or are you staying with someone close by?

[cdovego]

My Gram's - room for your rig. Chat at rd. 2.

[Garandman]

I replaced the front brake pads on the CRF100 last season and they seem to engage very late: bar is almost to the handlebars. I've taken up about as much slack as I can in the cable. Am I missing something?

[Kurlon]

How much life is left in the drum? At the wheel, the brake arm should have a little arrow by the pivot that sweeps over a little 'useful life' bar. How close to the end of that bar are you when the pads start to bite? That'll tell you if you've just stretched the crap out of the cable, or if you've worn the lining down enough that it needs to be redone.

[Garandman]

The brake pads are nearly new. So maybe the cable is stretched. The bike is in NH and the service manual is in Boston.

[Kurlon]

Bah, no need for a service manual. And remember, it's not just the pads that wear. The portion of the hub that the pads bite against is a pressed in steel liner, it tends to wear much quicker than say, stainless rotors, etc. Especially if you put aggressive sintered pads in. Take a look at the hub, near the pivot for the brake pull arm will be an arrow pointing down. There is a raised section of the hub under it. Squeeze the lever and see if that arrow is moving into the middle of that raised area, or trying to escape away from it.

[Garandman]

Just took a look at the bike. Both adjusters are screwed out to the max. Would it be typical for a cable to stretch? If not the pads must be worn out again though they have maybe 20 hours. I measured the drum ID and it was well within specs when we measured it.

Maybe I'll get some 3rd party pads instead of OEM.

[Kurlon]

XR100 drum brake fade has a useful tip. Pull the pads, see what they look like. EBC offers pads in 3 different compounds, 'race sintered' will get you maximum stopping power. https://www.procycle.us/bikepages/cr...00.html#brakes

[Garandman]

Basic problem is I am a bonehead.

Checked the lower adjuster - full out. Checked the arrow and it's about in the middle of travel.

Light dawns over Marblehead. I adjusted the throttle adjuster. The upper adjustment barrel was screwed in all the way. Backed it off and travel is now good, though still on the low side.

Presumably the manual has a cable length I can check it against. With a good hub and serviceable pads, I don't think I should be 80% of the way to maximum travel.

When we next replace the pads, should we stick with OEM or are there better aftermarket pads?

[Kurlon]

CRF100 pads are like oil threads, it all depends on who you ask. Generally, they all suck. You get more variation in stopping power from how you install and radius them compared to differences in pad compounds. That said, if you go OEM, groove them.