[Wild Man]

I only have 300 miles on my bike, still in the break in mode. 4,000 RPM (plus a little) seems to be best for me but it is not real smooth, seems to be a little surging going on.

This is on the highway where the speed limit is 65 mph mostly flat terrain. In my opinion lugging the machine is the worst thing you can do.

Thanks,

Terry

 

[YoBoody]

I only have 300 miles on my bike, still in the break in mode. 4,000 RPM (plus a little) seems to be best for me but it is not real smooth, seems to be a little surging going on.

This is on the highway where the speed limit is 65 mph mostly flat terrain. In my opinion lugging the machine is the worst thing you can do.

Thanks,

Terry

What do you mean by lugging?

 

[Wild Man]

What do you mean by lugging?

Lugging is when you are riding in too high a gear for your speed, an example would be riding at 2000 RPM in 6th gear.

 

[alepplew]

Lugging is when you are riding in too high a gear for your speed, an example would be riding at 2000 RPM in 6th gear.

I think from your other bikes you are used to engines with big heavy flywheels on the crank. The singles and parallel twins need that because they inherently come with huge vibrations and torque peaks.
In contrast the Ducati L (V 90°) twin cancels most vibration out due to its geometry. Those engines run smoothly with a very nimble flywheel, making them so sharp when revving up. However, put a variable load including a chain slack and they are torque-wise running less stable. At least that´s how I understand it. If I want to run mine steadily at let´s say 3000 rpm I need to be really steady with the throttle and use only micro changes. If I want to be more rough, I need to shift down. Thats the price you pay for such a low weight sharply accelerating engine. Instead of revving up some heavy flywheel it kicks your rear!

 

[alepplew]

Forgot to say: I try to avoid lugging /chain clattering/ roughness, since under-revving is clearly stressing the entire drive chain starting with the crankshaft bearings. This engine is not your big single pot that tuck tucks at walking speed and you simply open the throttle and your fat flywheel will even out all the lugging from the single piston. This is a racehorse and the engine design is coming from the track. I avoid torturing the bearings by any means and shift a lot. You will see, after a thorough careful break in, the real fun starts when overtaking and out of corner accelerating at 8k+ rpm . High revs is where the desmodromic valve actuators play their game so much superior to a traditional spring...

 

[silverluxe]

When my bike is started cold it runs butter smooth at 4000 RPM. Almost zenlike. But once it's up to temperature it gets rougher. It's still OK, but not butter smooth. I had to ride my bike home from the dealer on the interstate because my back highway is shut down for construction. I had it up to 80mph and I thought it was fairly smooth. Definitely smoother than my other two bikes. But the best feeling I've had is around 4000 RPM (indicated by the tach gauge.)

I'm also having to adjust coming from a 360 degree parallel twin and a 180 degree boxer. The Ducati engine is also more oversquare than any engine I've ever owned which also makes it wind up quicker.

 

[alepplew]

When my bike is started cold it runs butter smooth at 4000 RPM. Almost zenlike. But once it's up to temperature it gets rougher. It's still OK, but not butter smooth. ...

Maybe somebody is interested in why that mixture-enriched cold engine is running a tad more smooth. We pilots in our world of flying dinosaur engines still have to adjust the mixture manually ! Therefore we need to study this:

The graph shows (among other cryptics) EGT= exhaust gas temperature. Left is rich mix, right is lean. The highest point (dashed line) is where our pollution optimized catalyzed engines run when warm. When cold, they are run far to the left with a rich mixture, to compensate for fuel that condenses and gets lost on the way into the cylinder. Now look at the black HP=power curve: On the left (cold engine/rich mix) it is totally flat, no matter if mixture varies a little every piston stroke gives the same power. At the dashed line the power curve becomes steeply inclined. That means, unavoidable little variations of mixture (walking a bit left and right on that black curve, we are spraying fuel into a violent chaotic tornado of aspiration air) lead to large changes in power (up and down)between one combustion and the next. That makes the engine run more rough. When you over-lean the mixture in an airplane by hand, the engine will become so rough that you get scared it will jump of its mounts.

BTW, the graph also shows that you are messing with your cylinder head temperature (CHT) when changing the mixture. That popular remapping can definitively fry your engine when not done correctly...

 

[silverluxe]

I just assumed the richer fuel map for warm-up doesn't need to meet emissions laws

One wrong number typed into the excel spreadsheet for your fuel map may hole your piston in whatever gear/throttle ratio box you messed up It's quite crazy.

Then again I see at least three people per year at scooter rallies seize their engines because they want to be the fastest guy ever on a Vespa or Lambretta and think they can get away with too small of a main jet in their carburetor. In airplanes you just actually adjust to run lean at altitude, correct? Which probably conserves a lot of fuel in the sky.

 

[alepplew]

Exactly right. Given you have a thorough instrumentation you can also run the engine "lean of peak" to reduce fuel consumption, CHTs and stress on the engine. For that you need, however, to monitor all cylinders CHTs and EGTs. I have an instrument with 12 indicator bars for exactly that, and it is the only digital nonsense in a 6 cylinder air cooled 274 hp old plane The technique was developed as one of the first by Charles Lindbergh in the Spirit of St Louis, who taught other marines aviators about it for their long WWII overwater legs in the Pacific...

 

[scrambling]

I think 4000-4500 rpm is the magic number for this bike as a shift point, my cruising speed is about 6000 and feels good. anything lower than 4000 you are chugging, not a good thing

 

[chilira]

I just go by the feel of the pull and the sound of the engine. Most of my Harleys didn't have a tachometer.

 

[silverluxe]

Up to about 45mph the speedo is about 2-3mph fast. At 70mph the speedo is about 5mph fast. So you kind of have to wring it out a bit in order to keep up with traffic. I won't have an opinion about the most 'buzzy' RPM range until I've broken it in and can get up over 8000 RPM. 4000 in lower gears or 5000 in 5th and 6th feel good to me. The bike doesn't care.

 

[RamblingPath]

I just go by the feel of the pull and the sound of the engine. Most of my Harleys didn't have a tachometer.

Feel the same about gear indicators. Eyes up and on the road

 

[AnotherHobby]

I think 4000-4500 rpm is the magic number for this bike as a shift point, my cruising speed is about 6000 and feels good. anything lower than 4000 you are chugging, not a good thing

Now that I'm past 1500 miles, I disagree with your shift point.

The best shift point is when the little red lights flash on your instruments, just before the fuel cut. >

 

[semize]

Cruising in 1-5th gears feels good at 4k rpm. 3.75k feels like the lowest before a little roughness kicks in and 3.5k and lower feels like what you all are calling "chugging". However, I cant beleive thats the ideal cruising speed, 4k just seems high. Then again, I'm coming from a '75 Honda CB200. Is this pretty normal for high compression bikes?

 

[RamblingPath]

Cruising in 1-5th gears feels good at 4k rpm.

Then that's the right cruising speed.