Tired of '08 KTM 105XC

Hello! This is the 4th time I'm taking my son's KTM 105XC to the dealer shop. The last couple of races, including a GNCC race, he didn't finish due to overheating the motor, losing antifreeze and blowing up the motor. I'm tired of this crap; it's time to switch brands. What do you guys strongly recommand? We do Harescramble and next year we're planning to stick with AWRCS and GNCC series. Thank you.

Might want to post a little bit about your son, height, weight, are you still going for a 100cc class or 125? Youth? Youth with the expectation that this bike will last into class C adult? Want to stick with smokers or will you consider a 4-stroke?

I agree with the smacaroni - we need details  :)


Is it big bike switcharoo time?  Or do you plan on keeping him on big wheels for a while longer?


I'd think about switching to a 125 2 stroker (blue or yellow)  or maybe a KTM 200? 


If you want to remain on smaller bore and thinking about 4 strokes I'd maybe look at CRF150R. 


I had an 03 ktm 105sx, just recently sold it. That bike ran perfectly fine, always started on first kick, never shut off on me, and idled perfectly fine. It's not the problem with the ktm, it all comes down to how it's maintained. If you keep up with the regular maintenance, it shouldn't have any problems. I rode the hell out of mine and it ran fine for 11 years. The only problems I had were with the clutch. Any bike you buy, any brand can fail if it's not maintained. I'm not saying you don't maintain the bike, it might not be as reliable. If he's getting taller and heavier get him on a 125, or 250. I'd say a Honda, or a Suzuki. Reliable bikes with enough power to throw you off:)

KTM does like to runs small radiators on the little bikes, it can cause problems in the woods.  The new 50's are terrible, and the sand at Garrettsville kills them.


But, I think something else is going wrong.  What tracks did it overheat at?  That would make sense at Clintonville and Foxburg because of all the mud.  I saw a fried ignition at Clintonville, too.  Powerline Park  and Rock Run were wide open and should not have caused overheating.


Fuel filter plugged causing it to run lean?


Maybe you have a cracked head, or the head studs are pulling causing disappearing coolant, have seen both before on other bikes.


Some guys like engine ice, but that covers up other issues.


I know guys that run red, green, and blue superminis and all have held up well.

Edited by gsa102

Hello guys! I'm trying to provide a little more info, you've requested. Well, my son is 13, he's about 5'6" and 105lbs. Is good to mention that his riding style's extremely aggressive. For at least next season he's gonna be in super mini class, but it's also possible to keep him in that class for the next two years. It depends how fasy he grows and if he feels that he needs a bigger bike. About 2 or 4 stroke, not sure yet. He rode his buddy CRF 150 ( with high performance cylinder in it, and he liked it). I've heard people saying that those 4 strokes are designed for mx tracks, they're heavy and overheating in tight spots in the woods. Son here's what happened! During a CRA race (Lightning is considered one of most difficult tracks in CRA), the engine lost the antifreeze due to a cut hose, so he overheated the engine. Next day, I took the bike to the KTM dealer. After three days I picked it up "fixed"; they replaced the O ring on the head cylinder. Next weekend we went out for a ride. Kid went 2-3 laps on the mx track, rode it on the open field, then it happened again. Engine blew up after 15-20 minutes. Next day, again I took the bike to the KTM shop. I've drained the oil, I put some in a jar and I took that sample to the dealer shop. Well, they called me, bike's ready to be picked up. So, we picked up the bike Saturday, on our way to the GNCC at Powerline Park. Sunday morning when kid was on the starting line, he told me that there is a weird unusual noise in the engine. When he turned off the engine, I could hear a squicky noise (like an electric motor). He took off, he was 8th during a couple of turns, then he took the lead between mile markers 2-3. He caught up kids they started in 1st row, then bike blew up right where my friends where staying. He got DNF!!! Same procedure, Monday I took the bike back in the shop. They "fixed" again! When I asked what they foud wrong, they said that they replaced an O ring and they forgot to put oil in the transmission. After 3rd time bike was in the shop, they found the head cylinder warpped and the machined it 15 thousands. Two weeks ago, engine blew up again after a muddy race; kid only made 2 laps. Bike is in the shop now (4th time for the same issue) and they think the head cylinder threads are pulled and they want to put healy coils in it. Neither kid or myself don't trust the shop mechanics and the bike, no more; to much trouble! Last week he raced his 85 and won senior mini class. What should I do? Calling KTM Headquarter would be an option?!?! Thanks everyone!

My advice is to try a different mechanic. Clearly the shop you've been going to is either ignorant or forgetful. I can see the first time, maybe naively, replacing the O-ring and returning it the owner. But the second time? That warrants a top end tear-down to say the least and inspect the water pump too.

By now you may very well need a top end, transmission inspection and possibly bottom end rebuild. None of that is certain without inspecting the parts, but you don't run a bike w/o tranny oil and you don't send a bike back to the owner the second time, let alone a third!?, having performed the same "repair" as the first time.


Good luck.

I had the threads pull on a CR125 head, it was very hard to diagnose, and I may never have figured it out if I had not talked to someone who had the same problem.  We fixed it with helicoils and it held up until the kid sold it.  From what I understand, the helicoil fix will last.


But I agree with Smacaroni, have a different shop do it.  I would have a regular machine shop fix it.  I have to ask, was this Stillers working on it?


I know the kid that runs the CRF150 in AWRCS, and he doesn't talk about any overheating issues.  But I have been behind a few big CRFS steaming like a freight train in the woods.

Kx or RM supermini. More reliable just send off suspension to FC

The crf 150 is a good one too

Without an a1 wrench or becoming one a ktm is difficult to race day in day out...

I know people who do but they r a1 wrenches...

Edited by quarternac sr

It's the shop you are dealing with, not the bike.  The 1st time, OK the hose was cut...  stuff happens.  The shop should have pulled the top end and checked the head and cylinder to ensure nothing was warped when the bike overheated.  The 2nd and subsequent failures are due to the shop not checking / fixing the warped head in the 1st place. I'll bet the head was warped and no one looked at it until it was in the shop for the 3rd time...  now its too late... I would have not allowed then to shave the head, but forced them to replace it, (on their dime).  and forget to put oil in the tranny...  no... Come to think if it, I would have has the repairs (after the 1st time) on their dime...  and them now I'd want a refund for that as well...  


Tell them you want to speak to a KTM representative...  This is not a bike issue, but a shop issue...  You want the engine sent to a different shop, and want a complete overhaul.  Lower end and top end.   The 105 is a great bike.  KTM;s are very reliable, except when a shop doesn't preform the correct maint.  

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