Low RPMs All the Time = Problems? - Sportbike Forum: Sportbike Motorcycle Forums
 
LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old 07-05-2002, 06:56 PM Thread Starter
 
Join Date: Apr 2002
Posts: 528
Low RPMs All the Time = Problems?

My buddy with a 97 gixxer 6 has some problems with his bike and he claims it is due to the fact he does too much street riding...where the rpms are relatively low.

My question is, will riding at low rpms all the time affect the bike or engine in anyway?

Someone told me that riding at high rpms helps clean out the inside parts, is this true?
AlwaysNewbie is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 07-05-2002, 07:34 PM
 
Join Date: Apr 2000
Posts: 43
Talking Just puttin' along

Hey Newbie;

Your friend may have something there. Modern sportbike engines aren't really designed for cruising around town in a high gear and low RPM. Lugging it below the power band can cause some internal damage to the engine and transmission, not to mention premature wear on the internals. The "cleanliness" issue you mentioned has more to do with the oil gumming up the innards, the exhaust track getting carbonned up, and the intake getting fouled.

The instructor at the very first track day I participated in made a big thing about keeping the engine way up in the power band. Say between 8,000 RPM and redline for performance riding. Even higher for racing. It's better for the bike's engine, and the acceleration and engine braking is much better as well.

Now, I realize that humming along at 10,000 RPM/50MPH in first gear heading down to the 7-11 might sound a little outrageous, but in the long run it's better for the bike, the riderhas more control and let's face it.......it sounds good, too!

Anybody else want to wade in on this one?
Scooter is offline  
post #3 of 7 (permalink) Old 07-05-2002, 11:47 PM
 
Join Date: Jun 2002
Posts: 40
I disagree

The WORST thing you can do to your sport bike is to lug it. Beyond that, you should be OK. Todays sportbikes are tuned so well that you should never have a problem with carbon fouling of the exhaust or plug fouling. If the intake is becoming gummed up it is because you are experiencing reversion in the intake tract due to the RPMs being too low when you whack the throttle open. Virtually all engines have a 'sweet spot' where you can cruise along and then just roll on the throttle with no great amount of hesitation (bogging). That 'sweet spot' is lower RPM-wise in the lower gears. That is to say, you could be running along in say 2nd gear at 2500 RPM and roll on the throttle with no problem but in 4th or higher you would need 3500-4000 RPM in order to accelerate cleanly. It all depends on displacement and torque but back to your question.
I don't think low RPM riding will have any adverse effects on the engine as long as you don't lug or bog the engine when attempting to accelerate. Of course, thats just my opinion.
Green01SprintST is offline  
 
post #4 of 7 (permalink) Old 07-06-2002, 12:44 AM
 
Join Date: Dec 2001
Posts: 67
just what I needed, another excuse to drive around town in first and second gear all the time...
Nyquist_Theorem is offline  
post #5 of 7 (permalink) Old 07-06-2002, 07:43 AM
 
Join Date: Sep 2001
Posts: 1,547
I'm gonna have to disagree. Unless you keep it below 3k it ought to run fine, especially at lighter throttle settings. If you're gonna go around at full throttle below 4k you're asking for trouble. Other than that I find it hard to believe these race breed engines would have problems in city driving. And to suggest that 10k rpm is good for the engine is rediculous. Bad no, but definitely not going to improve anything.


I seriously doubt that this guy manages to keep the bike down that low unless he's really trying? What kind of riding and rpm's is he talking about? You'll have to find out because this question is seriously lame if he rides around above above 3k with trips up to 6k. This is enough to keep the engine happy (other than the theory which is likely correct that you better hit redline frequently near the end of break n to help get the rings to seat/seal propperly).

Fill us in on the details of his current problems and riding habits so we can make this thread a bit more useful.
apexismaximus is offline  
post #6 of 7 (permalink) Old 07-06-2002, 08:21 AM
 
Join Date: Jun 2001
Posts: 1,992
I agree with everyone's comments about not bogging or lugging the engine. I just wanted to add (not relevant, but just for information purposes) that running a 2-stroke at low RPM's for extended periods of time will ruin the engine. The main problem is all that oil in the intake mixture will collect on the cylinder wall, intake ports, reeds, and carbs. In a 2-stroke, you need to keep the intake velocity up (I.E. keep the RPM's up) to keep this crap from condensing inside the engine. To some small extent this same concept applies to the 4-stroke. I used to work at a lake and we had a 2-stroke outboard on our work barge. That barge never left the no-wake-zone, so it never went above a fast idle. We had to tear down that engine every few weeks, and totally rebuild it. I hear they finally got a 4-stroke engine on that boat, but I left before that happened.
Kevlar7R is offline  
post #7 of 7 (permalink) Old 07-06-2002, 12:17 PM
 
Join Date: Jan 2002
Posts: 6,400
Two stroke is NOT an engine one can lug.

Mind you on 4-stroke sportbikes one should not be lugging the engine.
Simply look at the Owner's Manual & you can see the writing between the lines that the engine should be broken in properly.
Even like cars if you break an engine in on low revs it will be happy there & lack power in higher revs, but if one breaks it in properly then it will sing from 5 grand up to full chat with decent power.
Still the above is NO REASON to be screaming around town on a 929 in lst to 2nd at 5 to 8 thou ----- time to scoot for the hwys with those revs & higher, but watch out for the cops.
Smitty is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Sportbike Forum: Sportbike Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome