KTM RC390 Top End Tear Down | Head, Cylinder, and Piston Removal

[@wernerxldata]

Next time check valve clearance before you dismount the head, so you can order the right shims with the other stuff needed 😊 Great video, easy to see how everything works with this engine.

[@ScramblerAustin]

This is awesome that you are doing these videos KZbin is seriously lacking in this kind of stuff for the rc390

[@GarageAddiction]

Glad you enjoy them, it's a fun bike and so far not too terrible to work on :)

[@MechanicsDIY]

indeed .

[@Jaahhhnnnn]

Excited for part two to come out for the engine refresh. I'm literally doing the same thing to my RC390 right now and the guidance is super helpful!

[@GarageAddiction]

Awesome! Hope all is going well with your bike. I’ve got about 2 weeks or so waiting on parts but hopefully they come faster than expected.

[@Jaahhhnnnn]

@@GarageAddiction I've got to pick up some more parts since my head gasket blew and made a mess of the internals. Quick question, can you tell me what size wrench you used for that case plug bolt in the very beginning of the video? I'm having a hell of a time figuring out the size wrench I need to buy.

[@collingilbert]

John the plug is a 14, it’s a snug fit so you may have to tap it in.

[@GarageAddiction]

Whoops replied with my other account, but yeah a 14 will do you.

[@Jaahhhnnnn]

@@GarageAddiction Kick ass, thanks dude!

[@francoojeda8452]

I went through the same process when my Duke 390 (2016) head gasket blew. When we opened up the engine, I also noticed that the gasket had such a small hole compared to cylinder coolant passage. The new gen 390 engine heads are a little different from the old ones. Hope to see it running soon!

[@GarageAddiction]

Yeah it still baffles me, seems like if you wanted a restrictor you'd just make a smaller passage. I just got the parts back today so hopefully back together by the weekend!

[@rguru2493]

@@GarageAddictioni think a Smaller passage = less coolant flow (low surface area and less coolant flow) so ensuring high volume of coolant in the head and reducing flow by gasket to ensure the coolant stays in the passage for some time

[@GarageAddiction]

@@rguru2493 Yeah I could see that, the system is so small it's pretty prone to heat soak and the rad gets incredibly hot after not too long. I'd really like to see double the rad capacity and dual fans on this.

[@MechanicsDIY]

opening that tenssion screw causes a big mess . the precice timing chain tenssioin is critical to prevent tottal loss of the engine . counting the turns when opening it will help to re install it as it was before. i just opened the housing 2 screws and removed it without changing the tenssion . (be carfull not to brake the paper gasket holding it using oil helps to lossen it ) then reinstalled it slowley turning each screw half a turn at a time , 2 make sure to pull the chain up and test i't set in the bottom gears before reinstalling the cam shaft top intake & ex gears 3 you don't have to replace a dirty piston , use carburator cleaner to remove the carbon . you shuld replace all the piston rings and all the gaskets when opening an engine . if you want to see witch piston must be replaced look for video engine problems knok knok part 3 on youtube

[@atvan933]

Thanks, your video so great. I wonder if i can upgrade engine ktm rc250/200 upto 390 by using KTM RC390's cylinder, piston, engine cylinder head, cam? or using another cylinders, piston?

[@GarageAddiction]

I'm not familiar enough with the 250/200 to say. I doubt either is built to handle the 390 kit because the 390 can barely keep itself together. The bikes have different part numbers between them so cross referencing those would be difficult without having both in hand. That being said the parts do look very similar and are probably scaled versions.

[@neurobits]

Thanks a lot! I’m just disassembling. Looks like the squared holes on your gasket got covered with carbon, leaving just a small hole for fluids. lol

[@neurobits]

Sorry, I just saw a new gasket and it has round holes. So, the squared holes at the block “liquified” the gasket 😮 I’m scared about what I’ll found inside my engine lol Cheers! Thanks again.

[@seenumeena3609]

Thank you bro ❤️❤️❤️

[@Freddi922]

After the new resurfaced head has it been pretty reliable since?

[@bve7397]

How hard is this? Thinking I need to replace my head gasket, im an avarage hobby mechanic. Just scared of the timing and all

[@findtherightbeat]

Thanks for sharing this video of the disassembly. How did you compensate for the timing change due the decking of the of mating surfaces?

[@GarageAddiction]

It was fairly flat so it just got a flat plate grind, it wasn’t enough to warrant any timing changes.

[@findtherightbeat]

@@GarageAddiction Thanks! I'm currently looking into the DUKE/RC platform at the moment and trying to learn online. By any chance, does the deck height differ between the 125/200/390 engines or is it just the crank, rod, cylinder and piston that's different from each other?

[@GarageAddiction]

I’m actually not sure what all the differences are, I imagine they have different top end bore, piston, and stroke. The diagrams look very similar in construction though.

[@findtherightbeat]

@@GarageAddiction I also tried scouring the net for forums or discussions between the cross compatibility of the parts but to no avail. Also, by any chance, would you know if someone has tried modding the intake length for the RC/Duke? I'm thinking that moving the powerband a little earlier would be better in the streets. I also haven't seen experimentation on porting and valve seat angles, which I think will help the engine.

[@GarageAddiction]

@@findtherightbeat Yeah I haven't seen much anywhere on actual engine comparisons or much in the way of tuning or tweaking outside of bolt ons and piggyback ecus. The facebook group has some knowledge but it's pretty sparse on that subject. I think the perceived fragility of the engine is a big turn off for many street riders and the racers keep things pretty close to the chest. The intake would be tough to mod other than the airbox and snorkel, I'm not sure the amount of work would be worth the gains compared to a gearing change.

[@TheVeilComplex]

I'm looking for the 22' manual. What manual did you use?

[@GarageAddiction]

I used a 2015 Duke manual that I found floating around on a manual website. I haven't been following the updates by year but I imagine the engine is roughly the same

[@alfredogiwisch2871]

Oil burning issues caused by overheating.

[@liruizhu2146]

The engine OHV is very similar to my Subaru Mower.

[@GarageAddiction]

I didn’t even realize Subaru made mowers, learning something every day.

[@jaiminparmar4690]

Does it affected the performance?

[@reneseib6532]

how many km has the bike done?

[@atncozkan5162]

Hi there.one of the 4 cover bolts of the top of engine is leaking very very little like 1mg of oil.is that a problem? Should i fix it? Thanks in advance

[@GarageAddiction]

The valve cover bolts have little rubber gaskets which are easily replaced if you have access to it. I'd take care of it when you get the chance to keep your engine clean and your rather costly oil in the bike. :)

[@atncozkan5162]

@@GarageAddiction yeah,i will definetly change those rubber gaskets.thanks sir

[@GarageAddiction]

Hopefully it’s a rear one for easy access!

[@atncozkan5162]

@@GarageAddiction its the one on the left and rear.i guess its accessable

[@rainielantonino7751]

how many km in the odo is that rc390 the block is almost new

[@GarageAddiction]

It was around 6700 miles or 10,700 km

[@rainielantonino7751]

@@GarageAddiction mine has 35,000km in the odo what can be the things i can replace for that odo? its still running good

[@GarageAddiction]

@@rainielantonino7751 I wouldn't touch a thing. Check the valves, keep up on fluid changes, you should be fine!

[@rainielantonino7751]

@@GarageAddiction thanks 🙏

[@rguru2493]

Which grade fuel did you use?

[@GarageAddiction]

91, not sure about the previous owner but I'd imagine 91 too.

[@bewseybill3691]

Great vid, but do not try to remove carbon with sharp metal objects. Leave to soak in soapy solution for 24 hours, then remove loose carbon with a piece of wood. Polish with a piece of 3M Scotch Brite and finally clean piston with a suitable parts cleaning solvent. Carbon deposits with in the combustion chamber are an inevitable and unavoidable consequence of the internal combustion engine.

[@GarageAddiction]

I agree, I knew this piston was leaving so it was more for demonstration purposes to pick at it haha. With less than 6k miles on the bike this was an incredible excess of carbon and that's what was unexpected.

[@bewseybill3691]

@@GarageAddiction Hello GA, I also have a 2016 Duke 390. It looks a good as the day I bought it. I don't ride it hard and only on dry summer days (not many off them in the UK) but having just done over 5000 miles it has become plagued with problems. I continually have to take up slack in the clutch lever, the ignition coil failed, the front disc became warped and now I am loosing coolant. I have renewed the water pump seals and it is still loosing coolant. It now looks like the head will have to come, which lead me to your video. Once I have sourced gaskets from my dealer, I will then tackle this job. Thanks. Bill

[@GarageAddiction]

@@bewseybill3691 hopefully it's a smooth ride for you from there. I have heard nothing but reliability issues from these bikes but other than the head gasket I've been mostly in the clear. I did just pick up an interesting idle issue which hopefully I can clear up soon.