Author Topic: Red line, rev limiter  (Read 2387 times)

alfadan

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Red line, rev limiter
« on: July 21, 2021, 02:31:40 PM »
I have always read that one should never go over the red line (8k in the Yager) if you expect to get any life out of your scooter.  My experience has been a little different.  I regularly ride at and above the red line without any problems and still at 22K miles have no performance degradation.

The red line is an indication that maximum horsepower has reached and any higher rpm will mean less available horsepower to push the scooter but if you still have throttle left, use it! The motor is fine with that.  Just don't go bumping the rev limiter which is about 9200rpm in the Yager. Your engine light will come on and you'll have to reset it and the limiter is telling you that valve damage is imminent if you continue.  I have spent hours at 8500rpm (72mph) and the scoot seems perfectly happy. My top speed is about 76mph at the limiter, 65mph at redline, 8K.

Mine is a 2010 and if I could find another scoot with as much practical storage space, ergonomic comfort, performance and reliability as this Yager I would buy it but it's just not out there.  I'm also looking for another Puig windshield but can't find that one either.

I'm going to ride this Yager until it dies but isn't showing any signs of it yet.  BTW I keep it looking brand new, not a scratch on it!

Iahawk

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Re: Red line, rev limiter
« Reply #1 on: July 21, 2021, 10:20:41 PM »
Welcome to the forum! A couple of questions….I assumed that the rev limiter kicked in at redline..but on yours the limiter allows an additional 1200 rpm above redline?? That seems excessive as redline is usually the safe limit for revs.

Second question…we love scoots that are in great shape..where are your pics?!
2010 People S200 - sold after 8 wonderful years!
2014 Ninja 300
1996 Honda Helix
1984 Honda Nighthawk 650

CROSSBOLT

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Re: Red line, rev limiter
« Reply #2 on: July 21, 2021, 11:30:07 PM »
Actually, horsepower is just a computed number based on torque and rpm. Hp generally peaks after the torque peak and begins to fall rapidly. Hp and/or watts can be a good comparison for the ability to do work or for roughly matching an engine to a known ower demand like a generator or a required vehicle speed. Acceleration and rate or angle of climb is decided by torque. Pulling ability is determined by available torque.

Redline supposedly based as a safe limit including a "service factor" to guarantee the lower end won't disassemble or valves won't float. Exceeding red line serves one purpose only: to validate the limit. The engineer gets a gold star on his evaluation IF the engine self destructs after redline plus his service factor.

Pilots who exceed the published limits after all the developmental testing and proving are generally fired and black-balled. Owners of machines that do this need to be known so others will never buy one of his vehicles.
Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

alfadan

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Re: Red line, rev limiter
« Reply #3 on: July 22, 2021, 06:46:06 PM »
Pics of my 2010 Yager 200i.

alfadan

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Re: Red line, rev limiter
« Reply #4 on: July 22, 2021, 06:47:46 PM »
Another pic.

alfadan

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Re: Red line, rev limiter
« Reply #5 on: July 22, 2021, 07:06:42 PM »
"Actually, horsepower is just a computed number based on torque and rpm. Hp generally peaks after the torque peak and begins to fall rapidly. Hp and/or watts can be a good comparison for the ability to do work or for roughly matching an engine to a known ower demand like a generator or a required vehicle speed. Acceleration and rate or angle of climb is decided by torque. Pulling ability is determined by available torque."

That is correct. No dispute.

"Redline supposedly based as a safe limit including a "service factor" to guarantee the lower end won't disassemble or valves won't float. Exceeding red line serves one purpose only: to validate the limit. The engineer gets a gold star on his evaluation IF the engine self destructs after redline plus his service factor."

Service factor is 1200 rpm. that's a lot of useable spectrum to tell riders they can't use. Consider the large number of scooters out there without tachometers at all who ride all day with WOT.  They're not worried about service factors. The rev limiter says STOP and that's all you need to know.

To clarify, the horsepower max is at the redline as you pointed out.  After that it takes power away from your engine just to maintain that rpm of 8K plus. If for whatever reason the motor can't push you any faster at WOT (wide open throttle) you have reached the upward most limit of your engine's power without having reached the rev limiter.  I'm 160 lbs and have always reached the rev limiter before running out of power (just twice though.)

Back to the pics...  Note the windshield baffle.  It really works BTW.  When my last Puig cracked I had to replace it with something until I found another one but this little thing works just fine.  Also, the tires are new Pirelli Angels and the road traction on them is the best I have ever experienced.  Had a pair of Avon Viper Strykes before, got 10K miles on them but the dry road gripping just wasn't there.


CROSSBOLT

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Re: Red line, rev limiter
« Reply #6 on: July 22, 2021, 07:59:21 PM »
Where did you get the windscreen baffle? Been looking at one of those to reduce the buffeting.
Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

alfadan

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Re: Red line, rev limiter
« Reply #7 on: July 22, 2021, 09:59:47 PM »
Where did you get the windscreen baffle? Been looking at one of those to reduce the buffeting.

I got mine on Amazon.  There are lots of them out there but the critical dimension should be at least 5" or more high and 11" wide. They're priced right as well.  Mine was about $32 and the brand was Lanqian.

CROSSBOLT

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Re: Red line, rev limiter
« Reply #8 on: July 22, 2021, 11:33:09 PM »
Where did you get the windscreen baffle? Been looking at one of those to reduce the buffeting.

I got mine on Amazon.  There are lots of them out there but the critical dimension should be at least 5" or more high and 11" wide. They're priced right as well.  Mine was about $32 and the brand was Lanqian.
Thanks! Appreciate it!
Karl

Three motorcycles 1960-1977 (restored a 1955 BSA)
Agility 50
Yager 200i
Downtown 300i
Navy tech, Ships Engineer, pilot and aircraft mechanic

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