blown head gasket

[hvlmike]

Blew the head gasket on our new 2017 rc390 yesterday. I was aware of the problems and made a lot of mods (spal fan, rad cap, water wetter and pcv with richer map) to hopefully avoid it. Blew any way at just 3000 miles! I've read that KTM has an updated cylinder/head that resolves the issue. Can anyone tell me the part numbers for the newer parts? If it's the same part number how do I know I'm getting the "updated" parts?

 

[=maz=]

Same part number...one of the members posted a picture, on this forum, of the difference.
Sorry I can't be of more help.

 

[Fangfactor]

The new head has a bridge in the centre of the water gallery
Apparently KTM have just released in the last couple of weeks (in Australia at least) another new version of the head gasket.
If the bikes out of warranty maybe the new gasket would be worth a try first.
If warranty is still valid try for the new head as well

 

[green_bread]

Its also been discussed that the head surfaces arent very "true" from the factory. If thats the case, theres nothing you can do to keep the gasket from blowing without resurfacing the mating surfaces.

 

[Formula390]

Blew the head gasket on our new 2017 rc390 yesterday. I was aware of the problems and made a lot of mods (spal fan, rad cap, water wetter and pcv with richer map) to hopefully avoid it. Blew any way at just 3000 miles! I've read that KTM has an updated cylinder/head that resolves the issue. Can anyone tell me the part numbers for the newer parts? If it's the same part number how do I know I'm getting the "updated" parts?

As others have said, the part number wasn't revised when they changed the head and added the bridge. If you post a photo of the head we can tell you if it's a new one or not. KTM should cover it and being a 17 you should still be well inside the warranty period. KTM has been covering it even outside of warranty window, but you have to have a dealer that will go to bat for you and not just give you a "Sorry, you're out of warranty" song and dance. So far I've only heard of one case where it wasn't covered and that was a crappy dealer in southern CA. This is the first 17 I've heard of that popped that wasn't also a racebike. Are you racing it? 3k miles sounds like a streetbike, but who knows. Also, are you SURE you got the system TOTALLY purged of air when you switched over to water wetter? Quite a few guys have had an accidental pop when they dumped their coolant and switched in something else. How long ago had you changed out the coolant? Not trying to be accusatory, just asking questions as this basic troubleshooting / post mortem for a failure.

 

[hvlmike]

As others have said, the part number wasn't revised when they changed the head and added the bridge. If you post a photo of the head we can tell you if it's a new one or not. KTM should cover it and being a 17 you should still be well inside the warranty period. KTM has been covering it even outside of warranty window, but you have to have a dealer that will go to bat for you and not just give you a "Sorry, you're out of warranty" song and dance. So far I've only heard of one case where it wasn't covered and that was a crappy dealer in southern CA. This is the first 17 I've heard of that popped that wasn't also a racebike. Are you racing it? 3k miles sounds like a streetbike, but who knows. Also, are you SURE you got the system TOTALLY purged of air when you switched over to water wetter? Quite a few guys have had an accidental pop when they dumped their coolant and switched in something else. How long ago had you changed out the coolant? Not trying to be accusatory, just asking questions as this basic troubleshooting / post mortem for a failure.

Thanks. Most of he miles are track miles (my wife is an instructor with a trackday provider). I've built alot of motors and read up on purging the air on the ktm system. All the mods were done at 500 miles. My wife was the service writer for the dealer we bought the bike at so they're cool...and I'm a machinist so I can do that work if needed. Oh...I bought new in Jan. 2018

 

[Formula390]

Thanks. Most of he miles are track miles (my wife is an instructor with a trackday provider). I've built alot of motors and read up on purging the air on the ktm system. All the mods were done at 500 miles. My wife was the service writer for the dealer we bought the bike at so they're cool...and I'm a machinist so I can do that work if needed.

Wow, 2500 track miles is impressive for a 17! Heck there's quite a few 15 bikes that are racers and track only bikes that haven't racked up that many miles! Sounds like you did everything right if it lived that long after. I guess now we just have to wait and see the photo of the head to know if it's a revised version or not.

 

[hvlmike]

Wow, 2500 track miles is impressive for a 17! Heck there's quite a few 15 bikes that are racers and track only bikes that haven't racked up that many miles! Sounds like you did everything right if it lived that long after. I guess now we just have to wait and see the photo of the head to know if it's a revised version or not.

being an instructor ...my wife rides at every trackday and can ride multiple groups during the day...so she racks up the miles pretty easy. But some of those 2500 miles were street too.

 

[Chuditch]

Oh no! I take it that this example of a blown head gasket applies to a bike that has been ridden close to it's limits (track time). Being in Australia, I always do a double take when I see the miles and then do the metric conversion. I was under the impression that the 2017 had a improved head/gasket setup, that's why I paid the money for a new 2017 instead of a 2015. Now it appears it hasn't... dopey me.

What do you think, if anything, this means for a similar bike used as a street hack, weekend hill runner?

 

[isaac_]

Oh no! I take it that this example of a blown head gasket applies to a bike that has been ridden close to it's limits (track time). Being in Australia, I always do a double take when I see the miles and then do the metric conversion. I was under the impression that the 2017 had a improved head/gasket setup, that's why I paid the money for a new 2017 instead of a 2015. Now it appears it hasn't... dopey me.

What do you think, if anything, this means for a similar bike used as a street hack, weekend hill runner?

I wouldn't get worked up yet.

 

[Chuditch]

I wouldn't get worked up yet.

Noted, thank you.

 

[ia02]

I would love to hear a follow up on this. Did we ever determine if the blown gasket was with the new head design or not?

 

[hvlmike]

Sorry I never did a follow up. Turns out the head gasket is fine. Shop did a leak down and compression test as well as pressure tested the radiator...no leaks were found. They topped off the coolant and put in fresh oil and It's been fine ever since! Cost me $400. ! I don't know why it over heated and lost most of the coolant before all this???...but 400 hard miles later and no issues.

 

[ia02]

That’s an unexpected outcome for sure. Must have just been air in the cooling system or something like that.

 

[zaster]

Sorry I never did a follow up. Turns out the head gasket is fine. Shop did a leak down and compression test as well as pressure tested the radiator...no leaks were found. They topped off the coolant and put in fresh oil and It's been fine ever since! Cost me $400. ! I don't know why it over heated and lost most of the coolant before all this???...but 400 hard miles later and no issues.

I'd still keep an eye on the gasket.
Had the same issue on my '15 and when I brought it in, the dealership could only determine missing coolant without finding any other fault
The gasket did fail eventually and they had to rebuilt the upper end of the motor on warranty of course.
No issues since.....