Help with a KTM 85XC (KTM85SX)

jrminiquad

PR Addict
Picked up a 2008 85XC this week. It was purchased new Christmas of 2010, so it's less than three years old and I got it for $1500. It also came with an extra set of mint Excel big wheel rims with Rad hubs, so I think I got a good deal.

Noticed right away that when the kick start lever is closed it hits the pipe. It rattles constantly when riding. It doesn't look like there is any adjusting. I am assuming this is not normal.?

After being ridden for a couple hours it was spraying oil out from the rubber sleeve between the pipe and silencer. I know there aren't supposed to be clamps on there, bad boot maybe? I threw a hose clamp on there temporarily and it seemed to stop it.

Lastly, my son is coming off of an RM85 and says it doesn't seem like the KTM comes on the powerband quite as soon. I told him it's probably just the gearing as it's stock 14-46 and his Suzuki is 13-47. He races MX so thinking of going to a 48 rear. Thoughts on that?
Did not have a chance to check the float level yet but my son did point out that there were numerous cracks in the rubber intake boot between the carbs and reeds. Couldn't tell if any were deep enough for air to get in but I slapped some sealer on there and ordered a new one.

In the mean time this bog is driving him crazy. Out of six jumps on his practice track it only repeats on two specific jumps. He also took it out on our road and ran it WOT thru all six gears with nary a sputter. He also hopped back on his RM85 and swears it's quicker than the KTM and said it feels like it has a restrictor on it. He's only ridden his "new to us" KTM about five hours and he's wanting to get rid of it.

Anyone, any other thoughts on what to check?
 
You are mixing the gas way too rich. Or your jetting is way too rich. We suggest using Motoex premix and mixing it 50:1 . Check the reeds and see if they are cracked. The kicker could be worn out. The splines could be wore or the pipe could be bent if the kicker is hitting the pipe. The cracks should be surface cracks and will not cause the problems you are experiencing. With regard to the gearing a lot of Riders use different gearing for different tracks. I see by the KTM Tech Sheet that the normal jetting on this KTM is main jet 118, needle jet 2.6, idle jet 45, jet needle N5HG , needle position 3rd from the top, air adjustment screw open 1.5. Your spark plug is a BR9ECMVX. Hope this helps you

Candy at Holeshot KTM
 
Thanks for the quick reply Candy.

I think I have the kick start lever taken care of, just slipped a rubber sleeve over horizontal portion of the lever. At least we don't have to hear the rattling now.

It had a fuel tank of gas when we got it. When I asked the previous owner what they were mixing it at, and he just said "whatever the oil bottle calls for", so hard to say what he had it mixed at. He was using Motorex though. We run Lucas at 40:1 in our RM85 and I now have a tank of that in the KTM. Seems like it might be helping a bit.

I have new sprockets on the way, as well as a new chain, just to get away from the O-ring chain that is stock on the XC.

The bog can't be figured out. Never happen when we went to a neighbor's track to ride or on a half hour of trail riding. Just the two specific jumps on our practice track. Weird. Gonna check for water behind the ignition cover and change plugs and reeds/boot.
 
a little more help maybe

Still too rich for the oil to fuel mixture. Please consider checking the splines on the kicker. It rattles for a reason.
Please consider looking over the exhaust to see if it is bent. If you send me the VIN# on this KTM I will check to see if there are any open Tech Bulletins or open Warranty issues for you. Oh! please keep in mind that after market non oem front sprockets often do not fit...meaning an extra problem for you. It has to do with the thickness of the after market front sprockets. Nothing wrong with an o-ring chain
Best of Luck. This is an awesome KTM Bike
Candy
 
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