KTM 790 Duke Forum banner
1 - 16 of 16 Posts

·
Top Speed guru
Joined
·
80 Posts
Discussion Starter · #1 · (Edited)
I only have about 165 miles on my 890, but it's enough to form an honest opinion... finally, and I'm all in. First off, I can never leave anything completely stock, so right off the bat I installed a new Wings exhaust, same as my 790, added the hi-flow airbox lid, and went with the Booster Plug this time instead of the Coober ECU. The additional sensors on the 890 make fuel mapping more precise and the Booster Plug addition ran clean from bottom to top from day one. My 790, even with the much more expensive Coober ECU didn't run as crisp and the engine even died on occasion for no apparent reason.

As for the new riding position, the hype makes more of it than it really is. I like the improvement, the lower, flatter bars, and the raised, rear set pegs, but the feeling still isn't unlike the 790, but slightly more aggressive. The suspension, though still being run in, is still a bit harsh over rough or square edged surfaces like the 790. Being adjustable, I'm still playing with it, and it allows more adjustability and I'm adapting it to my riding style. I like it, but it's also not a night and day improvement. The engine, well after only 25 miles I couldn't take the stock muffler and made the above mentioned changes. The stock muffler has a nice tone, but is much too tame sounding. The upgraded engine wants to breathe, and who am I to deny that...

As for the engine, well, in the tight stuff it just plain rocks. Midrange power is quite a bit better. On one of my local canyon roads I find I can even run a taller gear through a few of the twisty sections making better time with the engine not working as hard as the 790 running through in 2nd where the 890 3rd gear is possible. In track mode the front wheel loves to dance above the pavement, lofting out of the corners effortlessly. My 790 took quite a bit of coaxing to get the front tire to leave mother earth. When I'm really pushing it, right now I prefer Sport Mode as I can ride even more aggressive and keep the front end mostly planted, though as I become more used to the bike I'm sure I'll use Track Mode even more. I love the engine in the tight stuff. Sadly, on the longer up hill straights, it is definitely faster, but could still use more in my opinion. The guys I ride with have very powerful sport bikes and I feel I have the advantage on most of the tighter stuff, but still want for more on the faster straights. I love that it pisses them off that a smaller bike like this can give a liter bike a real run for its money on everything but full power straights. This makes me happy!

The Brembo Brakes are powerful. I find I can run it in deeper, or at least at first I could because I could get slowed down so much faster with less effort. After about 50-60 miles of hard riding though, it developed a harsh vibration when braking hard at speed (front brake). I thought maybe the rotors had warped. I mean it feels pretty bad. So much so that when I got home I was planning on taking it back to the dealer to see if this was covered under warranty. I talked to my buddy that has a 1199 Ducati Panigale and he suggested I wait and ride it a little longer. He feels the brakes need to "run in" and that maybe I shouldn't run it so hard so soon, and let the pads have a chance to "seat" to the rotors. I don't know if this is what's happening, but that's where I'm at right now. I will take it for some easier rides this week and see if they improve before returning to the dealership. I know everyone has there magic potion for the perfect break in procedure. The book says stay below 6500 rpm for the first 600 miles. That's great for some, but I've never done this. I ride them hard from the get go and do exceed the 6500 rpm range, but never for extended periods, and I do vary the throttle so all good there.

This is the first time I've experienced the brake issue. Overall I love the bike, am happy I made the change, and look forward to more riding. Cheers for now.
20200524_102118.jpg
 

·
Top Speed guru
Joined
·
80 Posts
Discussion Starter · #3 ·
So I have maybe 250 miles on my 890R now. The brakes still feel a bit of chatter, but not nearly as much as before. Every time I ride it they improve. I'm sure they are fine. Was accelerating from a light going uphill towards my work. I 2nd gear hard roll on the front wheel lifted into the air. Still getting used to this as my 790 didn't have the beans to do this without serious effort. Having lots of fun and can't wait till my next weekend. ride!
 
  • Like
Reactions: J D

·
Registered
Joined
·
1,838 Posts
Not knocking - but an observation. The Coober takes time to adapt. I expect to run about approx 1/2 tank (road use) before it makes any real attempt to alter things and then another 1/2 tank to improve, adopt, adapt. After that it's spot on. Predictive adaption is NOT instant. Auto-Tune with the PCV is exactly the same.

The high flow airbox lid - WILL ime cause the "dying" thing. The airbox is designed to use the Helmholtz effect (esp high revs) and adding the open lid screws with it.
I had tried the lid before and as there is little to no evidence it actually does anything remarkable on it's own, I went back stock. And when I went back stock - it died (just once) after 1/2 tank too.

I did another test last week (we learn through experimentation) - Put openlid on - and used the 790 to commute. after 150-ish kms could feel the COOBER adapting to the "change" and there was the dying - just once or twice. After 180kms no more dying.

So I know what is to come in another 1/2 tank.

ime (&o) the open lid assists a bit in midrange - feels more willing - but equally seems to sap strength up in the revvy bit. Wish I had a Dyno to play with.
 

·
Top Speed guru
Joined
·
80 Posts
Discussion Starter · #5 ·
I did run the Coober in the past on my 790 and while it worked well, the Booster Plug I have run on several bikes with good results for a fraction of the cost. With the extra sensors on the 890 I felt the Booster Plug would be fine. The bike runs really strong in its current state with the hi-flow air box lid, Booster Plug and Wings muffler. Just adding a muffler without increasing air intake hinders additional air flow which is needed to increase power. I'm still in break-in mode but stil enjoy romps in the canyons every chance I get. What a fun bike...
 
  • Like
Reactions: Mayhem

·
Cry Baby
Joined
·
158 Posts
Adding a muffler does nothing to hinder additional air flow. In fact, you will get marginally more air flow from a free flowing exhaust. What you won't get is more top end power unless you also adjust the fueling.
 

·
Registered
Joined
·
1,838 Posts
The original KTM tail pipe is actually "straight through" and the exit hole is no smaller than the collector - so it pretty much is a zero restriction pipe.

The Wings (which I run also).
With the dB killer in is if anything marginally quieter than stock. With dB killer out it's less than 3dB louder (under twice as loud).
It makes no real gains power wise. More importantly - makes no losses!. Unlike some others.

Where I would discuss gains is Booster-Plug vs COOBER.

The Booster plug simply fools the ECU to thinking it is colder than it really is. Running richer is not ALWAYS the right thing to do - but, I agree, it's easier to comprehend. And over 30% throttle and about 60% rpms then will help some. It certainly does not harm.

The COOBER is a different beastie all together - NOT aimed at WOT riding.

The COOBER alters short term AFR but also (rather importantly) it alters the ignition timing dynamically. Something that you can also do with the PCV ignition add-on.
This can mean (if done properly) that the base tune in the ECU can be left lean for cruising and the timing and fueling can be altered to allow better acceleration.
It is based (I believe) on the rate of change in certain values rather than specific table values.

I did do some brief testing very early on with my COOBER. You can absolutely feel a change in engine response at moderate throttle change where there was none without.
EXACTLY how and where, I do not know, as I have no Dyno - but it is measuring TPS and intercepts (maybe modifies - read on) crank position and 100% intercepts/modifies timing and injector pulses.

It also (I believe from observation) lies a little to the ECU via the CPS. And this is how it encourages the ECU to richen the base tune under acceleration.
It's hard to explain until you see it happening. It actually worried me at first until I sat and thought about what I was seeing.

If I was going to upgrade to an 890 (finances and sphincters permitting) - I would 100% add a COOBER once the bike was run in.
Finaces - well we all know that - The wheel lift on on the 890 has me a bit worried.
Luckily my 790 was second hand and "just" run in 😁
 

·
Top Speed guru
Joined
·
80 Posts
Discussion Starter · #8 ·
Adding a muffler does nothing to hinder additional air flow. In fact, you will get marginally more air flow from a free flowing exhaust. What you won't get is more top end power unless you also adjust the fueling.
I disagree. You will not get full benefit from a freer flowing exhaust capable of exiting more air if you do not bring more air in. An engine in simplistic form is an air pump. The more air you can move in a given amount of time the more power output. A high flow muffler alone mostly just makes more noise.
 

·
Super Moderator
'09 CBR1000RR
Joined
·
638 Posts
I disagree. You will not get full benefit from a freer flowing exhaust capable of exiting more air if you do not bring more air in. An engine in simplistic form is an air pump. The more air you can move in a given amount of time the more power output. A high flow muffler alone mostly just makes more noise.
Why does it sould like you're both saying the same thing and not actually in disagreement here?
 

·
Top Speed guru
Joined
·
80 Posts
Discussion Starter · #12 ·
Went on a spirited ride with a few fast friends. Two 890Rs a Yamaha R6, and a new Triumph Tiger Pro. I've ridden several times with the R6 pilot on my 790, and on any decent stretch he would pull me on the straights. Interestingly, now I pull him pretty well off the corners and the first part of the straights by enough that the 890 clearly has the advantage. On one really long, straight stretch the R6 got away from me, but that was the only time, and I'm still in break in mode and actually hit the rev limiter a few times which was a bit of a concern. One odd thing that happened, after some point my quickshifter quit working and I could only shift using the clutch. I pulled over, shut it off and waited a short period. When I restarted it and took off, it worked fine again. Any one else experience this? It seems almost like turning the bike off then restarting it was like a computer reboot? Anyways, other than that the bike worked great and is so much fun. I tend to run in Track Mode on these types of rides with slip set at 4. Hard acceleration the bike lifts slightly which is a hoot. Happy camper so far!
 

·
Registered
Joined
·
2 Posts
I disagree. You will not get full benefit from a freer flowing exhaust capable of exiting more air if you do not bring more air in. An engine in simplistic form is an air pump. The more air you can move in a given amount of time the more power output. A high flow muffler alone mostly just makes more noise.
...just makes more noise - and enemies of motorcycles. The minute gain on an already very powerful engine is, in my mind, not worth the additional people who will vote to ban or restrict motorcycles, however they can. True we have rights but we also have responsibilities.
End of sermon...🙂
 

·
Registered
Joined
·
40 Posts
Regarding the brakes: check the front rotors for dark spots, signs of overheating. Also, remove and check the pads to see if they look glossy or glazed. Take a sheet of 120-180 grit sandpaper and place it on a flat surface. Run the pads in a figure 8 over the sandpaper until the glossy sheen is totally gone and the pad has a uniform finish. clean off all brake dust from the pads. lightly sand the rotors with the same paper to remove any deposits and clean with compressed air and brake cleaner.

Go ride 100 miles and do some light to moderate braking to bed-in the new pad surface. Should be good to go from there.
 

·
Registered
Joined
·
8 Posts
What extra sensors do you mean?

You said "The more air you can move in a given amount of time the more power output." I would add that you actually need to take into account the AFR. If the engine is a little bit on the lean side just improving the airflow will make it leaner and it will lose power.

I did run the Coober in the past on my 790 and while it worked well, the Booster Plug I have run on several bikes with good results for a fraction of the cost. With the extra sensors on the 890 I felt the Booster Plug would be fine. The bike runs really strong in its current state with the hi-flow air box lid, Booster Plug and Wings muffler. Just adding a muffler without increasing air intake hinders additional air flow which is needed to increase power. I'm still in break-in mode but stil enjoy romps in the canyons every chance I get. What a fun bike...
 
1 - 16 of 16 Posts
Top