KTM RC390 Top End Rebuild 

Thank you for watching!

Thanks! I can't imagine the carnage in there with snapped valves, going to fix it up or source a new engine?

Thank you!

Glad it was helpful!

Thank you!

Thank you!

Came out of a 2017 but I wouldn't be surprised if they threw an older generation motor in some of the first run.

@@GarageAddiction hopefully I'm wrong about what I saw. I was looking at the video on my phone (small screen).

This bike was great for a while but has started with trouble again so you may be right

@@GarageAddiction the dealer screwed mine up three times and then when the warranty expired KTM conveniently forgot all the conversations we had about this. Spent my own money to buy a newer motor with less than 300 miles and it's been great ever since.

Glad to hear! I’m not sure what I’ll end up doing but it seems like another engine out is in the cards

At 44 seconds you can barely make out the marking on top of the piston which points to the exhaust port

Thank you!

It would have saved me some time for sure but I think I pulled the cam 2 times to get it perfect anyway haha

@@GarageAddiction It was meant to prevent the waiting time for ordering the shims... Sometimes I've got them a day later, sometimes more than a week ;)

Thanks! I have a 2017. The piston kit is the same for tons of years since there have been almost no changes. No real need to replace the piston, I did so while I was in there as it was caked in crazy hard carbon. The part number I went with is 90230007010 which I think lists 2013 as the year. I picked up a bunch of parts when I went through the engine, mainly all the orings in the head, a new oil pressure sensor because I accidentally smacked mine, spark plug, and a fuel filter. I would get new head studs if I was going to do it again, I didn't think about them when I ordered everything.

Yeah I've eliminated most possibilities now. Planning on drilling a weep hole and pressure testing the cooling system (not by the rad cap as the seal is poor) If it turns out to be the cases it'll be fun tearing the whole engine apart :/

I just got the hot cams shims, the valves, buckets, retainers etc are all stock. I did see that you can get most of the valve train as a kit through dealers: VALVE KIT 390 DUKE ON DEMAND 90236030010

I don't know if I'd be able to juggle the rings and cylinder on this bike. Easy enough on minis though!

I didn’t see any with a larger coolant passage, I’m interested though. I skipped the high compression because of how high strung they are and I’d wanted to make sure everything was working well at stock power before throwing a bit more at it.

I didn't get new head bolts but after some reading it looks like that's a good idea. You can leave the piston and rod if they're in good condition. They probably will be, I replaced mine while I was in there with the amount of carbon on it and slightly worn side skirts. There is a thin head gasket kit that sounds like it bumps the compression and runs well but I opted for stock right now. While you're in there check the valves and swap the plug since it's a nightmare to get to.

@@GarageAddiction thanks. I was thinking after I posted, that it might be very difficult to get the piston rings squeezed in from the bottom, without getting the ring compressor thing stuck in there...

Yeah no need to mess with the cylinder or piston if they look fine. It’s a lot easier of a job to just swap the head gasket and studs. Also I’d be very impressed if anyone could keep the piston on the rod and get it into the cylinder haha

@@GarageAddiction oh I see, I was thinking of doing the lower gasket between cylinder and block while I was there, but I guess there is no need if it's not leaking.

@@nictarver2988 yeah I wouldn't worry about the base gasket if you're just in there for the head.

My bike is ride by wire, I think that was a 2017 change but I could be wrong.

@@GarageAddiction yeah right I found online manual for duke 390 2016 study material I couldn't see RBW tech or unit on TB. Change was done in 2018

Check out this thread: www.ktmduke390forum.com/threads/ktm-duke-390-self-study-manual.1810/page-4

www.ktmduke390forum.com/threads/ktm-duke-390-self-study-manual.1810/page-4 Linking a forum thread reminds me of my youth.

Thanks ! Keep up the good content

Thank you!

You should check the valve clearance for sure, with oil and filter changes I wouldn't worry about cracking the engine open unless something feels different or you see some smoke out the exhaust, coolant loss. I don't think KTM provides intervals for pistons on these engines.

@GarageAddiction there is no smoke no coolant loss will get it checked with valuve clearance thank you so much 👍

There is a marking on the top of the piston that goes on the exhaust side. I think I mumbled something about exhaust instead of properly explaining what I was doing.

@@GarageAddiction okay was just making sure they were aligned right didnt want u to have any problems just makin sure thing were good

Much appreciated, I actually rotated the cylinder at one point and installed it backwards. I threw something across the garage and took a beer break after that.

Been a minute since I did it but I want to say it was about $300 tools/parts

It had about 5500 miles / 8850km on it when I rebuilt it and it's at about 6200m / 9977km now. I bought it with the head gasket leaking so I can't speak to what it went through before me but it's probably my most finicky bike. Cheers!

Not sure what the noise would be, being intermittent it may be something knocking around. Coolant temp could be anything from high ambient temps with a stock setup, water pump seals leaking, or a blown head gasket.

Everything is new coolant lvl is ok no leak and the head is new one

Is it possible for any sensors error

@@mohanmano4969 hmm it's possible, I have zero experience with that though

Anyhow thanks mate for sharing your thoughts

ex. 0.13 - .017mm int. 0.08 - 0.12mm

@@GarageAddiction thanq from agera automotive ❤️

I think ktm have since enlarged these figures a bit.

I don’t think I’ve ever owned a pair of Levi’s haha

It's got a throttle body injector

@@GarageAddiction so it's a closed loop single point injection system I am looking at the feasibility of an lpg conversion for a Duke 390

That sounds like an interesting project for sure

@@GarageAddiction it's more like a stupid project for me 😁 The issue is the tank, I think under the seat there is enough seat for a gas tank, something like 5 to 7 liter, but it would be fiberglass internally lined with nitrile rubber Because the main issue here is actually where to put the new lpg tank or whether you can use the main tank for lpg - easy to find out with a compressor to pressure test

@@GarageAddiction what's the deposit material? Is it steel? Aluminium?