Varadero 125 rough idle?

[rancevas]

Hello, please tell me if this is normal, as I really have no idea. 4 strokes are a quite new teritory for me.

My carburated Honda Varadero 125 (2004) has smooth accelleration/decelleration. Doesn't stall during idle or anything like that. Starts quite easily.

But when it idles, I can see the rpm indicator very slightly fluctuating from time to time. Between +- 150 rpm when idling at 1500.

Is this normal or abnormal?
if this is not adressed, will it cause issues in the future?
Should RPM at idle on two cylinder four stroke be stable and not move one bit?

Thanks!
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Get off my lawn

[Teflon-Mike]

Is it a rough idle? Or a dodgy tachometer?
Bike's 15 years old, and by now likely well past its prime, and spent most of that duration at the tender mercy of know-nuffink-learners... its a wonder it hasn't had the out-put sprocket welded to the shaft.... TBH.... to within four-thou, under water, whilst playing the bag-pipes.... (Sorry, little in-joke and jab at the legend of the bunny-guard)

Is it a cable driven, mechanical tachometer, or an electronic one off the ignition pulses? Go check the book? What? You don't have one!! Well, that's where you aught start!!

If its a mechanically driven cable tach, that sounds pretty normal, they do that with age, and or its the first signs that the cable has about had its day... before spending anything more, 'maybe' just swap the cable and see if telemetry wobble goes away. IF you cant just live with the little tacho-wobble... some bikes don't even have one you know!

If its an electronic, ignition pulse driven tach, they take a signal as in a click count off the pulses on the ignition feed to give indication of how many revs engine spinning. Electrickery then turns that into an output, either on a galvanometer.. ie volt-meter, with a dial behind marked in RPM's rather than Volts... or via a stepper motor that yurns as many degrees as the electrickery tells it. Most likely a galvo type dial, and good odds that any wobble on the needle at low revs is just hum in the works and the return-spring that pulls the needle back to naught, getting a bit old... live with it, or pull it apart and clean it out, and hope that a) you dont loose anything and can put it all back together, or b) the spring, which probably isn't totally broke righyt now, doesn't completely break when you try!

Way to test 'properly' if the idle is fluctuating, is to put a work-shop strobe on the magneto rotor, and look for a timing mark moving back and forth when the light flashes at fixed rate.. some more convoluted electrical test meters have a function for this; but that's how you test the actual idle speed, at the crank.. with another, trusted way of measuring the rpm's, not the rather vague and inaccurate dial on the dash... though you could try another one and see if it still wobbles...

But... if bike is running happily enough, what the rev-counter says makes little odds... like I said, many bikes don't have any, so unless its a real problem... its not a problem!
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My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[rancevas]

[Easy-X]

Wow... "really no idea, 4 strokes are new to me" and yet you dive straight into an engine rebuild.

Are ppl getting braver these days... or its it the other thing?
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Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[rancevas]

[Sister Sledge]

Could you post a video to show us what you mean?
In the video show the rpm indicator and also have sound so we can hear the engine.
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CCM 404 DS

[Easy-X]