More overheating

[MotoKam]

This seems to be a fairly popular topic, so here's my 2 cents.

I got my RC390 in June and I've put 8900 miles on it commuting to San Francisco each day.

Three times it's overheated and stalled when I got back to town in the afternoon. It takes about 10 minutes before I can start it up again. The first time it was about 100 degrees. I discovered the fan was not plugged in. The last time was yesterday and it was only 89 degrees.

Before, after I plugged it in, I would hear the fan running very loudly. Now it seem very quite and doesn't seem to be moving much air.

I've read in other threads about this being a warranty problem. But since my dealer wanted to charge me for the kick stand falling off after 2000 miles, I am not interested in their opinion (30 years of consistently crappy service doesn't bolster one's confidence).

I ordered the SPAL fan and I'll do the Engine Ice swap. Afterward, I'll post my findings.

One other thing I noticed was that after the first overheating episode, it started consuming oil. It used about 200mL per 500 miles. I changed the oil (Motul 15w50) and that problem went away.

Thanks for all the info!

 

[big_sur]

I'd say it's definitely a warranty issue, and you can always escalate it to your regional rep if you're not happy with your dealer, but barring that path, engine ice and a re-map\PCV (to make it run richer) should help with your temperature issue.

Regarding oil, I would say 200mL is probably within the margin of error for what's left in the crank case, etc so I don't know that I'd worry too much about that unless you see a lot of blue smoke coming out of the exhaust or something.

 

[MotoKam]

Yeah. It didn't seem like a lot of oil. When I change it, it takes 2.2 L, so that's less than 10%.

I'm guessing that the overheating, plus the perpetual high speed running, led to a break down that allowed it to seep past the rings and burn. I never saw any smoke or drips, and after the oil change it uses about 100mL per 1000 miles.

 

[gbabyracing]

Check the nut in the water pump impeller. It may also be loosening. It is not a "lock" type nut.

 

[ToraTora]

Check the cooling fan to see if it failed. It happened to my friend's Duke. They ended up replacing the whole fan assembly.

 

[Diploman]

MotoKam, The 390 manual lists engine oil capacity as 1.7L. If you are filling with 2.2L, that is a serious overfill that could damage your engine. It is better to err on the cautious underfill side than overfill. Many 390 owners use 1.6L as the baseline fill volume, then make small adjustments as dictated by the sight glass. I suggest you drain .5 L from your engine before starting it again.

 

[Fasteddy]

MotoKam, The 390 manual lists engine oil capacity as 1.7L. If you are filling with 2.2L, that is a serious overfill that could damage your engine. It is better to err on the cautious underfill side than overfill. Many 390 owners use 1.6L as the baseline fill volume, then make small adjustments as dictated by the sight glass. I suggest you drain .5 L from your engine before starting it again.

FWIW,
"manual lists engine oil capacity as 1.7L." actually it is 1.7 Quarts and 1.6 Liters in shop manual and owners manual. Both also warn of under filling, twice. I also question the statement that
"overfill that could damage your engine" I would go with better to err on the full side as opposed to under fill.

Info
Too little engine oil or poor-quality engine oil results in premature wear to the
engine.

23.3.1 Engine oil
Engine oil
23.3.2
Engine oil (SAE 15W/50) (p. 184)
23.4
1.6 l (1.7 qt.)

 

[Treachery]

Does sound like a fan failure; I didn't read it here, but IIRC the fan blades themselves can come loose from the motor shaft. That for sure won't move much air. Engine Ice won't help much in that situation either.

 

[gbabyracing]

KTM told me to proactively dimple and locktite the radiator fan blade set screw. Also be sure you pull your water pump cover and replace the impeller nut with a locking type. KTM says the back back cover on the radiator fan is designed to improve the fan flow through the radiator. Not sure if I believe that part.

 

[MotoKam]

The deed is done!

The SPAL fan was installed after cutting down the one oversized mounting lug with a Dremel and cut-off wheel and adapting the wires to the KTM plug (no wire cutting or soldering needed). It starts and flows air very quietly.

The cooling system was flushed until only clear water flowed. Then I replaced the O-ring at the water pump and refilled it with Engine Ice.

It was a great opportunity to blow out all the bugs and rocks from 9700 miles of high speed commuting.

Everything went back together quite easily and it runs as good as ever. 195 miles to work and back tomorrow will let me know if everything is just so. Too bad it won't be hot (boo hoo!)

The best part is that it was done in a couple of hours, not the week or two it would take for the dealer to diagnose the failure, get approval from the factory for warranty repair, and order the part from the fan motor mine somewhere in Asia just to have it fail again as soon as it got hot!

At $35/day extra to drive the car to work, not to mention the extra 3 hours of life lost in the commute each day, the $100 I spent on this upgrade easily makes sense.

 

[MotoKam]

This is the one Spal 30103011 5.2" puller fan

Here you will find everything you need to know about the SPAL Fan , including a step by step replacement tutorial .Spal Fan Instal How To - KTM Duke 390 Forum

This is a fantastic tutorial. The only thing I did differently for my overheating RC390, was to carefully remove the connector blades from the plastic plug. The blades are the same except that the middle hole needs to be punched out to clip into the KTM fan plug. This will prevent any need to cut the wires or splice anything together. It's as solid as the stock connection.

It's been 1000 miles since I did the upgrade and it works brilliantly!

The temp gauge never gets close to the top anymore. I can feel the hot air blowing through at stop lights around town (that might be rough on 100+ degree days, oh well). But it doesn't overheat at all any more.

 

[ueihtran]

My fan is also noisy but it cuts off. Seems to be working, but I'm not sure. My question is how noisy is too noisy?
Also, my engine temperate get to about where the arrow is pointing. Is this normal? outside air temperature average around 65F when I'm riding.

 

[OldVet]

Yep normal, no need to worry until it hits the H...

 

[MrGrody]

Yep normal, no need to worry until it hits the H...

Ya , mine has never filled either of the bars in that "separated" section. Even riding in 107°f weather.

 

[Biker]

KTM told me to proactively dimple and locktite the radiator fan blade set screw. Also be sure you pull your water pump cover and replace the impeller nut with a locking type. KTM says the back back cover on the radiator fan is designed to improve the fan flow through the radiator. Not sure if I believe that part.

Any pics to we've as a guide?
Does the coolant have to be drained?
Thanks

 

[ss4dmk]

I've been having this overheating since quite recently. It's like, as soon as i start the bike, the radiator fan kicks on. And the temp goes to max within a minute of running. Also noticed that the coolant level is almost at min.

My bike has been driven for 30000+ km. I've had overheating issues before because of a blown gasket, approx before 5000 km of riding. Even had the temp sensor and thermostat replaced (that's what the KTM mechanic told me). What could be the problem now?

Edit: This morning, my bike started and was able to drive for a little while longer before the fan started. It sounded abnormal, the fan kept speeding up and slowing down suddenly, temp kept changing between 9 and 8 points. In the evening, the bike wouldn't even start. Even if I managed to start, the engine stops when I leave the throttle.

This is getting weirded and weirded.

 

[m3hl]

This thread is scary...

 

[Wa2fst]

Mines a 2015track use only and his st started last year spitting out the over flow got it bled out really good start of this year no issues. Then my last track weekend barely spits out overflow but runs to the top bar shuts down coming into pits. Rebled but couldnt get to stay halfway cool. Rider behind me said he could smell coolant no white smoke. Unforunately i had knee surgery so ive had no time to get oil drained to see if i blew a gasket. I replaced the rad cap with better cap 1st of this year before my 1st track day. Not sure if its a thermostat issue. Soon as im walking again ill most likely haul it to chad and drop off.

 

[Wa2fst]

Ill check the water pump nut and look into the fan also. Bad part is one of the cup kids i see at track days told me to lock tight that impeller nut and i friggin forgot all about it

 

[Deleted member 452]

Most of my overheating problems were caused by leaking head gaskets (stock one and thin head gasket from Cometic). Combustion chamber gas was intermittently sneaking by the gasket into the cooling system which was also causing coolant to puke out the overflow (even at normal operating temperature). The dealer said the overflow tank was filled with too much coolant every time I talked to them about this until the motor died 2 weeks after my warranty expired. I now have 7K miles on my new motor with resurfaced head & cylinder using the OEM gasket with Permatex copper spray sealant with no overheating issues and coolant level have remained constant with no puking even while riding 4 days in the desert @ 100 degrees a couple months ago. My water pump also failed at 5K miles on my first engine but the head gasket was the real culprit of all the overheating issues that plagued me for 9K miles.