KTM Thumper Discussion

[Rsquared]

Originally Posted by Tourmeister

JD jet kit came Friday... Now to get it installed.

[Tourmeister]

Originally Posted by Rsquared

I just have to go find one of those little cotter pin thingies and a pair of tweezers right?

[Rsquared]

Originally Posted by Tourmeister

I just have to go find one of those little cotter pin thingies and a pair of tweezers right?

And a can of cleaner.

[Tourmeister]

Originally Posted by Rsquared

And a can of cleaner.

Got lots of that

[KeithE]

I have OEM FT and Rear sprockets on my 09 450 EXC, Whatvis the best sprocket options. The stocks ones seem too tall, looking for more bottom end.

[KeithE]

What do I need to do to prep my 09 EXC for ridding in Colorado. Elev. Of 10k feet +/-.

[Rsquared]

Originally Posted by KeithE

I have OEM FT and Rear sprockets on my 09 450 EXC, Whatvis the best sprocket options. The stocks ones seem too tall, looking for more bottom end.

Dual Sport, 14/50. Tight woods, Hare Scramble 13/50-52

Originally Posted by KeithE

What do I need to do to prep my 09 EXC for ridding in Colorado. Elev. Of 10k feet +/-.

Waterless coolant, fan kit, JD jet kit, 13/50-52 gearing.

[Lulu7404]

Originally Posted by Rsquared

Dual Sport, 14/50. Tight woods, Hare Scramble 13/50-52



Waterless coolant, fan kit, JD jet kit, 13/50-52 gearing.

Agreed on the above. I ran 14/48 on the FI 500 EXC up there last week. I didn't need lower but it would have been nice. Thinking of going with 14/50 next month when I go back. Fan came on several times during grunt work. You will need diff jets for sure, the kit will tell you which depending on the elevation. My buddy just bought an 06 450 EXC yesterday. He has 13/54, stock was 14/50. First is about done at 6 mph. I can get near 17mph on the 500 as I have it geared now. The 500 will lug pretty good. Not familiar with the 450 yet.

[_RG_]

Agreed...14/52 JD jet kit set for 9000+ If you stay on faster jeep trails then the fan is nice but you can live without it. Get off on some tighter single track or get stuck in a gully turning around and that fan will be very much needed.

[Tourmeister]

Got my goodies in the mail a few days ago: fan kit, new brake pads front and rear, and engine cooloant for a complete flush. JD jet kit came last week. Already have the 13/52 gearing. Now to get it all together and ready for the trip! Should have AC in my garage sometime Monday afternoon Just dropped a load to get all new shop lights, more outlets, and the AC. The new lights are fantastic and I can almost see what I am doing... I just need to spend a hair more and get some glasses so I can actually see what I am doing

[Gravel Guy]

Originally Posted by Tourmeister

Got my goodies in the mail a few days ago: fan kit, new brake pads front and rear, and engine cooloant for a complete flush. JD jet kit came last week. Already have the 13/52 gearing. Now to get it all together and ready for the trip! Should have AC in my garage sometime Monday afternoon Just dropped a load to get all new shop lights, more outlets, and the AC. The new lights are fantastic and I can almost see what I am doing... I just need to spend a hair more and get some glasses so I can actually see what I am doing

+1 on the glasses.....I just got my first pair...

[Tourmeister]

Well, as of this morning, my garage now has AC Of course now I no longer have any excuse for not getting the work done on my bike

[_RG_]

OK...here's a first for me but I'll bet several of you folks have a bunch of experience with this...

Just replaced my water pump seals on the 530. While I hand my hands dirty I went ahead and replaced the two plastic gears and oil pump shaft along with the 100 oil jet for the 125...and tightened that danged starter clutch. It was loose and now the bike cranks immediately. That problem is for real folks.

Here's the next thing...I had a chance to take a close look at both my sprockets. Seems the CS sprocket looked like a crosscut circular saw blade and the rear had a funky shape around each pointy tooth that looked tragically unsymmetrical. These are stock equipment...steel up front, aluminum in the rear. I lubed these things before every ride. Time for new, eh?

I ordered new...steel and steel. But, now (you guessed it) the chain is jumping each rev. Measured it...need a new one. So, I ordered an RK 520...plain chain...not an X ring...not even an O ring...just plain ole roller chain. You may recall, I lube with that teflon chain guard stuff before every ride. The question is: Have I just blown $20 on a chain that'll last for a few days or did I just avoid getting fleeced for the $80+ cost of the X, O ring chains? What do y'all think?

[Tourmeister]

IF you can keep the chain real clean, it should work. Clean means no dirt/rust where things move. The benefit of the o-ring/x-ring is that it keeps dirt out of the area where parts are rubbing on each other. I've had some folks say not to lube a dirt chain because that just makes dirt stick to it. They like to use the o/x rings since they are internally lubed, then leave them dry. I occasionally squirt mine with WD-40 after washing the bike just to keep them from rusting because the rust can be abrasive and wear the gasket rings. As little mileage as I am putting on my 530 in a year, I figure my X-ring will last a long time.

Did you replace those plastic pump gears with metal ones? Why did you have to replace the oil shaft/jet? Just an upgrade kind of thing?

[_RG_]

Yep, the gears replacement, oil pump shaft and oil jet are all upgrades. The parts are surprisingly cheap so why not? The gears are still plastic...just wider (supposedly stronger). The shaft is stouter material and the bigger oil jet takes care of a known oiling deficit at a critical point. All of this stuff lives in the same neighborhood so doing them all is just as easy as getting one...and I HAD to deal with those water pump seals anyway.

The issue with the starter clutch seems to have taken on the mystique of an urban legend. Let me tell you, it's nothing but a slip-disk clutch...just like the one on an old Ford shredder I grew up running. Hit one good fire ant hill and that thing slips one rev, may as well get off and tighten it then and there. Same with that KTM starter clutch. If it slips, it ain't getting any better on it's own.

I had to make a tool for holding the clutch basket while removing the big nut that holds it all on. I'll send it to anyone here who needs it. Nothing fancy but it works.

[RollingJ]

I'm afraid you will regret not getting a o/x ring chain. I have that same RK 520 basic chain and it stretches like crazy and will eat your new sprockets. I have it on my little 250 so it's not even being tested that hard. I MIGHT have 1000 miles on it and I can pull the chain 1/4 inch off of the rear of the driven sprocket.

Get a good DID or RK o/x ring chain and give it a little chain wax every once in a while.

[_RG_]

Joel...you saved me. I was looking at some company info about measuring chains and they said essentially the same thing you did. If you ride in dirt, that roller chain's life is measured in hours. It pays to use a sealed chain. (clean street riding, not so much)

Called Rocky mtn. and changed the order just in time. RK 520 exw on the way. :tumb:

Thanks guys.

[Irishcoffee]

There is never a good reason to use a non oring chain. Even on the street. Any open chain will be dry in just a very short ride and then you have metal on metal with zero lubrication and excessive friction. That makes for a noisy, short chain/sprocket life. A sealed chain will give many clean, happy, trouble, adjustment free miles. Plus more horsepower.

[_RG_]

This made for some interesting reading about chains. Not long but fairly instructive.

http://www.dirttricks.com/Chain-Wear.htm

[TwoSmokeDS]

Originally Posted by Irishcoffee

There is never a good reason to use a non oring chain.

Yes there is. Before you put a bike with rusty chains up for sale on Craigslist.