Best RPM to run at for cruising?

[nobunaga]

Hey guys,
Question for all: What RMP do you guys set at while cruising down the highway?
I've been pretty much setting on 4000. Felt like a comfortable purr there.
Problem is, I noticed when i wash the bike the end of the muffler is coated with black, gooey carbon. When it sets and idles in the driveway in the morning before leaving for work, I notice black spots where it shot carbon crud onto the cement. And then tonight my wife was driving behind me on the way home, and when I gunned it to get around this car she said a cloud of black smoke shot out the back :confused: I've only got a little over 4000 miles on the bike so it shouldn't be an issue with age.
Am i taking it too easy on the engine? I've been shifting at 4000 at each gear, then cruising at 4000 in 5th (80mph) on the highway (for all you police officers out there, that 80 is a type-o).
Or could this be a sign of something more sinister?

Nobu

[messenger13]

It's a non-issue. All LT's do it. To protect the valves, upon nailing the throttle BMW dumps fuel into that motor the way I drink sweet tea when I'm in the south. The result: a lot of black smoke, and soot on the tail pipe. (Um...the LT, not me!) :D

[JPSpen]

Don't Idle the LT. IT's not necessary. It causes the excessive carbon buildup..

Just starterup and go.

Another reason for the black stuff. But the fuel mapping causes it to run a bit rich so what you're seeing is normal for the way you're treating her.

Another thing. The LT's engine doesn't even start having fun till above 5000 RPM

Don't be afraid to run it up close to the redline. don't keep it there, you can go there anytime. And cruising at 4K on the interstate is about normal.

Try it, you'll like it.


John

[grifscoots]

When it sets and idles in the driveway in the morning before leaving for work, I notice black spots where it shot carbon crud onto the cement. NobuDon't let it idle in the driveway. The manual says not to warm the bike up, but to start it up and ride off. I usually kept it below 4k while it warmed up.

[bghubr]

Of course the 80 mph on the clock is really incorrect. It's probably in the range of 72-73 mpg.

4000 rpm is perfecct. The engine loves to cruise at this speed. And don't worry until you get around 10k on the odometer the engine is still breaking in.

[CajunBass]

I ride mine like an old man. But then I AM an old man. I usually shift about 2500-3000 rpm. Never saw any sense in winding it up any harder since I'd be hitting the speed limit in most places around here in 1st or 2nd gear. 4,000 or so will give me about 80 mph (indicated) on the interstate,

[dshealey]

I ride mine like an old man. But then I AM an old man. I usually shift about 2500-3000 rpm. Never saw any sense in winding it up any harder since I'd be hitting the speed limit in most places around here in 1st or 2nd gear. 4,000 or so will give me about 80 mph (indicated) on the interstate,

I am an old man too, but did not ride like one. I tried to never let the LT get lower than 3000 rpm at any time other than starting out. I typically ran between 3000 and 7000, and when just riding around shifted around 5000.

[donsobeck]

You can pull away quickly on a cold start but be very careful on slow speed low RPM moves as you can kill the engine very easily, and down you go.


DON

[nobunaga]

Thanks for the advice fellas!
I'll be a little more aggressive with her. I won't let her idle in the morning.
One question on that though... What about the cold morning coming up (Michigan)? Should i not let her set and warm up before starting out?

It's good to know that I don't have something weird going on. I kinda figured i was being too easy on her. I guess that just the LT's nature.

Nobu

[JATownsend]

Thanks for the advice fellas!
I'll be a little more aggressive with her. I won't let her idle in the morning.
One question on that though... What about the cold morning coming up (Michigan)? Should i not let her set and warm up before starting out?...
Nobu
I would be more concerned with cold tires than a cold engine. As others have said, "Start it up and ride away!" The CAT Converter doesn't like the rich mixture at startup and idle, just clogs it up!

Keep it under 4000 RPMs for the first mile or so. Then...let her rip! :)

[grifscoots]

On top of that, the oil doesn't circulate well when cold. That's why the BMW engineer's say to ride off on her. I used to keep her around three grand till she started warming up, moved up to four and when fully warm, flog her.

[Bob204bc]

I ride mine like an old man. But then I AM an old man. I usually shift about 2500-3000 rpm. Never saw any sense in winding it up any harder since I'd be hitting the speed limit in most places around here in 1st or 2nd gear. 4,000 or so will give me about 80 mph (indicated) on the interstate,

A couple of comments:

It is my understanding that the alternator doesn't cover the full electrical load until the engine is spinning at 3,000 rpm. I may be wrong about that but I'd rather keep the battery charged (motronic issues at low voltage & etc.).

These engines like to rev. The power and responsiveness below 4,000 is pretty weak so cruising at 2500 revs leaves no margin for goosing the throttle to get out of the way when necessary. This flying brick engine is known for going hundreds of thousands of miles without problem. We should be so lucky with the rest of the machine.

My recommendation: Don't baby the machine. Run it hard and enjoy it's performance.

Re. warm-ups: Just like a fuel injected car - if the engine runs smoothly, drive it. It will warm up better in 2 miles on the road that in twenty minutes in your driveway.

[slowflyn]

I rarely used 5th gear on the LT unless I was conserving fuel on a long distance trip. My preference was/is to keep the rev's up, it wont hurt anything except your gas mileage. I think by keeping the rpm's low you are not able to take advantage of engine braking to slow down quickly. The were a few times I was glad I had some help from the engine slowing that beast down.

[K1200LTryder]

I cruise at an RPM that the speed limit will allow....give or take a few MPH, usually 5-10 over the limit depending on traffic. Having a 2000 LT with the long legged 5th gear, the bike is useless in 5th below 50MPH, and comes alive after about 65MPH...but a 60MPH cruise yields 3000RPM...and the best mileage...mid 50's.

No black soot probs, no cat converter either... :D

Cold starting, I let it warm up for a minute, then ride it easy until the temp is up and the thermostat has opened. Normal riding I shift around 5000RPM, another story with an open road or onramp though....she loves to sing above 7000 revs.... :D

[LAF]

Are "We" sure about this?

I have never started any motor and just driven off. I let mine idle and in the winter i will ride in the teens. Would never dream of no warm up on anything. I don't know the specifics but the O2 Sensor probably don't get warm for 30-60 seconds, and then I am sure there has to be an enrichment circuit for a period of time according to engine/coolant temp?

Also oil flow is low, not sure how big of a deal it is in K bike, but in a twin it is very important.

Also I was alway taught not to ride a bike until the head is warm to the touch, and then gently to it is up to full temp.

Just not sure I would not warm a motor, and especially in the PA winters here.

I do use a side stand but hold my bike upright lean right, for 30-60 seconds when I stop.

And I use Sea Foam every couple of tanks 1oz to gallon of gas.

Don't Idle the LT. IT's not necessary. It causes the excessive carbon buildup..

Just starterup and go.

Another reason for the black stuff. But the fuel mapping causes it to run a bit rich so what you're seeing is normal for the way you're treating her.

Another thing. The LT's engine doesn't even start having fun till above 5000 RPM

Don't be afraid to run it up close to the redline. don't keep it there, you can go there anytime. And cruising at 4K on the interstate is about normal.

Try it, you'll like it.


John

[Voyager]

Are "We" sure about this?

I have never started any motor and just driven off. I let mine idle and in the winter i will ride in the teens. Would never dream of no warm up on anything. I don't know the specifics but the O2 Sensor probably don't get warm for 30-60 seconds, and then I am sure there has to be an enrichment circuit for a period of time according to engine/coolant temp?

Also oil flow is low, not sure how big of a deal it is in K bike, but in a twin it is very important.

Also I was alway taught not to ride a bike until the head is warm to the touch, and then gently to it is up to full temp.

Just not sure I would not warm a motor, and especially in the PA winters here.

I do use a side stand but hold my bike upright lean right, for 30-60 seconds when I stop.

And I use Sea Foam every couple of tanks 1oz to gallon of gas.


I don't know if "we" are sure, but I am sure. Most modern vehicles are much better served by a very short idle period before starting out. Drive easily at first to let things warm, but idling more than 30 seconds is not beneficial and can be harmful. Most owner's manuals now recommend that you minimize idling. I say do whatever your owner's manual says to do.

Matt

[grifscoots]

Are "We" sure about this?

We have read our owner's manual and it says to just ride off. We have opinions of engineer's that state idling deprives the K engine of oil in areas of the engine when cold. We are happy if you desire to warm your bike up first before riding and this is just our opinion of what we have read and heard.:D

[andy]

We have read our owner's manual

Is that "pluralis majestatis"? LOL

United States Navy (http://en.wikipedia.org/wiki/United_States_Navy) Admiral (http://en.wikipedia.org/wiki/Admiral) Hyman G. Rickover (http://en.wikipedia.org/wiki/Hyman_G._Rickover) told a subordinate who used the royal we: "Three groups are permitted that usage: pregnant women, royalty, and schizophrenics. Which one are you?"

[rglassma]

Start it and ride !!!! That is the way it is designed...

[grifscoots]

Is that "pluralis majestatis"? LOL

United States Navy (http://en.wikipedia.org/wiki/United_States_Navy) Admiral (http://en.wikipedia.org/wiki/Admiral) Hyman G. Rickover (http://en.wikipedia.org/wiki/Hyman_G._Rickover) told a subordinate who used the royal we: "Three groups are permitted that usage: pregnant women, royalty, and schizophrenics. Which one are you?"Well, lessee now, I'm not preggers, royal blood??? (hah!), whatever in the world does that leave? Let me ask the committee in my head and I'll get back to you.

[nobunaga]

Coming in this morning to work (6:00 am) I caught myself doing the same damn thing i always do. I noticed that i had started the bike up and THEN put on my helmet and gloves (letting it idle) and I was shifting the bike around 4000... after telling myself to perk it up a bit.
Stupid habits!
Okay, going home tonight will be different!... :rolleyes:

[pcra]

5th gear, 2990 RPM, 110km/h, 4,5L/100km

[UncleRock]

I find it pretty hard to get the front wheel off the ground, even with feet on back pegs below 6,500rpm :)
Rock