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RPM's randomly when higher
Posted: Sat May 16, 2009 12:48 am
by SprEE*MP*
I was ridding home the other night, then all of a sudden my engines RPM's when really high and i got going 50km/h, then RPM's whent back to normal, and speed whent back down between 40-45....any idea whats up?
Posted: Sat May 16, 2009 9:51 am
by noiseguy
Mmm. They do that sometimes when they're running hot. Pull and check your spark plug color at the insulator; what plug are you running? Might considering going cooler on it assuming there's no other mods on your bike. Do you know what main jet you have?
RPM
Posted: Sun May 17, 2009 1:46 pm
by uspmale
I'd check for vacuum leaks.
That is a symptom of a air leak,causing a lean mixture, under a vibration condition.
Check it and let us know.
greg
Idle Speed Enigma
Posted: Mon May 18, 2009 12:11 pm
by Wheelman-111
Greetings:
I concur with The Noisy One and Greg on the high speed RPM issue. Vacuum leaks at high RPM are sometimes vibration-induced. Crank seals, base gasket, even a small crack in the intake or gaskets can surface only at high RPM. Sudden Hot Flashes not caused by Menopause.
I'll go one further with an interesting Flash symptom:
When I final-tuned it I let the engine warm to heat sink, set the IDLE speed to ~1800. You'd expect a warm engine to settle back to this same base Idle speed anytime you ride but
NOOO!!
Most times if it's warm out, Idle speed seems to go to 3000 initially, then settle down to 2700 or so. Then again sometimes it seems to want to stick to 1400 - barely enough to stay alive. Finally on occasion it's done all 3 during the same ride, in no recognizable order.
All I can say is that it seems to be ambient temperature-dependent. Temps on the CHT gauge always seem to settle at 275-300 at idle, regardless of outside temperature.
It doesn't seem to be a sticky throttle slide, bystarter issue or clogged carb. (The Arreche is less than 2 months old...) I'm starting to think it's the zones of magnetic (polar) forces on the earth...
Posted: Thu May 21, 2009 8:49 pm
by SprEE*MP*
My carb fell off...could the carb lossening, giving more air, have anything to do with it?
Posted: Thu May 21, 2009 9:04 pm
by maddog
check your fuel line, this ethenol corn crap eats it up, bring back the lead, which also makes any paint job last 50yrs
RPM
Posted: Thu May 21, 2009 10:05 pm
by uspmale
Yes,
loose carb = lean condition.