[1jzsupra]

Whelp,
I decided to go ahead and create a build post for the old duke. I have a 2016 390 with just about 23,500 miles on it.

I'll try and keep things chronological.

Bike as it sits at the moment.

MIVV GP Exhaust setup

2nd Failed auto tensioner. Pin broke in the same spot as the last time.

I have a powder coating setup at home and decided to powder coat my valve cover.

This is the 2nd air box I have purchased that has cracked in the exact same spot.

The replacement setup: (Chimera Intake)

Installed the Gray Area KTM shift shaft support and an Ebay rod to eliminate pretty much all shift slope. The "Short" shifter is amazing.

Installed the Yamaha R6 rear shock and put in some slightly heavier front fork oil.

 

[1jzsupra]

Power Commander V and WB2 Autotuner setup

Suspected coolant leaking past water pump seals.... Changed water pump seals out.

Changed out my ignition setup. I am still looking to see how the ignition system can be improved (Coil on plug or a stronger coil)

Turns out it wasn't my water pump seal.... 23,300 miles, suspected BHG.

Clean spot on the head

Corresponding head gasket clean spot

An interesting discovery. The old timing chain for whatever reason was eating into everything. I filed it down and cleaned it up.

 

[1jzsupra]

Another view of the head gasket and the head.

The timing chain was insanely worn out, I made a video on it. You can see here I was starting to drift more and more and was not able to get them to line up. This was creating a condition that made it extremely difficult to start my bike.

Parts:

Valve Cover Gasket
Valve Cover bolt grommets
Spark plug tube O-rings
"High" compression head gasket, which is just a 2-layer gasket instead of a three.
Titanium retainers.
Gray Area KTM stainless valves
New head bolts
New Circlip for the piston
New timing chain guide
New timing chain
Manual tensioner
New valve stem seals

Did some minor porting on the exhaust side and new crush seal

 

[1jzsupra]

Used the old 600 grit, glass and dycem trick to flatten the head out. and the block.

Completed the assembly.

A few other random photos. I had to Helicoil another cam cradle bolt (That makes 2 of them using a torque wrench.) Also, the top of the piston before cleaning everything up.

Pretty clean in there for almost 23,300 miles?

 

[shush319]

Good stuff brother! You get time on it with the thin head gasket installed, get it tuned up? Mine is running super strong

So glad when my head gasket went, it blew out the other way & no coolant went into the rest of the motor. All it did was blow the coolant out the overflow bottle and onto me from the motor's compression. All @ 90+ MPH, LOL.

 

[1jzsupra]

Good stuff brother! You get time on it with the thin head gasket installed, get it tuned up? Mine is running super strong

So glad when my head gasket went, it blew out the other way & no coolant went into the rest of the motor. All it did was blow the coolant out the overflow bottle and onto me from the motor's compression. All @ 90+ MPH, LOL.

She is running GREAT! there is still a spot in the map that needs some love, but honestly the WB2 is doing a pretty good job getting the map sorted. It has been tricky getting it tuned right with the intake setup and the larger injector. I'm glad I got that WB2 for so cheap. You story sounds horrible lol. I wouldn't want hot ass coolant hitting me or the back tire lol.

 

[shush319]

She is running GREAT! there is still a spot in the map that needs some love, but honestly the WB2 is doing a pretty good job getting the map sorted. It has been tricky getting it tuned right with the intake setup and the larger injector. I'm glad I got that WB2 for so cheap. You story sounds horrible lol. I wouldn't want hot ass coolant hitting me or the back tire lol.

Track experience kept me upright!! I know what to do when I go off the track well over 100mph, done it several times. Also grew up racing Flat Track, so controlling slides is embedded in my DNA. My leather jacket took most of the hot coolant too, what did get on my pants did not burn me anywhere. Definitely lucky it wasn't worse though.

 

[1jzsupra]

Track experience kept me upright!! I know what to do when I go off the track well over 100mph, done it several times. Also grew up racing Flat Track, so controlling slides is embedded in my DNA. My leather jacket took most of the hot coolant too, what did get on my pants did not burn me anywhere. Definitely lucky it wasn't worse though.

I would say you got lucky, but it sounds like skill was more of a factor that day.

 

[duke200]

Best post ever! Quick question: any opinions for the head gasket failure? Not properly tightening? Material of gasket? Overheating?

Sent from my A80Pro using Tapatalk

 

[1jzsupra]

Best post ever! Quick question: any opinions for the head gasket failure? Not properly tightening? Material of gasket? Overheating?

Sent from my A80Pro using Tapatalk

Combination of heat and straightness of the head.

 

[1jzsupra]

Bath time.

 

[duke200]

Ι believe I won't have the same problem with the adventure. It has 2 ventilators. I will check the head for tightening torque values though at coming major service (lubricants, filters, spark plugs, valve clearance, break fluids, engine coolant)

Sent from my A80Pro using Tapatalk

 

[1jzsupra]

Ι believe I won't have the same problem with the adventure. It has 2 ventilators. I will check the head for tightening torque values though at coming major service (lubricants, filters, spark plugs, valve clearance, break fluids, engine coolant)

Sent from my A80Pro using Tapatalk

Another member on the group suggested retorquing the head. Might be worth considering

 

[1jzsupra]

At some point I'll be getting a tyga header. Went ahead and cleaned up the exhaust manifold. They are notorious for having a **** load of thick welds.

 

[1jzsupra]

 

[KTMasean]

Strange as I recently had the header off my 200 and it is as smooth as a babies bud.

At some point I'll be getting a tyga header. Went ahead and cleaned up the exhaust manifold. They are notorious for having a **** load of thick welds. View attachment 54810
View attachment 54809
View attachment 54808

 

[1jzsupra]

Strange as I recently had the header off my 200 and it is as smooth as a babies bud.

Maybe you bad the better welder that day haha.

 

[KTMasean]

I have not taken off the header pipe on my 390 (yet) but shall report my findings here when I swap to TYGA.
Interesting though my 200 has a flange with 3 bolt holes.

 

[1jzsupra]

I have not taken off the header pipe on my 390 (yet) but shall report my findings here when I swap to TYGA.
Interesting though my 200 has a flange with 3 bolt holes.

At some point I'll be grabbing up a TYGA header as well.

 

[KTMasean]

As my 390 is used in Thailand (far better road conditions) I still consider to install the full TYGA under engine exhaust as ground clearance is much less of an issue there (or in Malaysia).
For Laos it's at least 30% off-road so I need all the clearance possible 😄