Skipping a beat on idle!

[Active Rascal]

Hi all,

My bike (1997 -AR) Skips a beat on tick over, and has been doing for a while now. A fellow AR owner suggested it may be an air leak somewhere? I have checked all pipes etc under seat are clean and not cracked, all seems OK. I have fiddled with the screw that is next to the carb, not sure what it does or what it should be set at. (It's not on carb, just above to the right I think- maybe throttle position, or air/vacuum system??)

To be honest, this isn't really a problem as it doens't affect the bike's performance, just sounds odd and I wondered if anyone has any suggestions? Could be something simple.

Thanks in advance,

Shaun.

[delvey91]

Mine does the same if im holding on the front brake whilst idleing, also does your engine pitch change if you change from 2nd to first holding the clutch in coming to a stop? Mine always does that aswell, No idea why

[jontymiller]

Delvey check your clutch adjustment on the handle, if the revs drop when you put it into gear the clutch is still engaging slightly. Does it inch forward slowly on a flat piece of ground when you release the brakes and still hold in the clutch?

[jontymiller]

Knackered knows more about the mixture screw than I do, but there are plenty of discussions about it in here. Have a search for carb settings or mixture screw. Also when last did you check your plug?

[knackeredMk1]

AR - You're looking at a 13 year old 2 stroke with a whacky engine system it really is going to miss the odd beat at idle. I wouldn't worry about it at all.

Air screw should be adjusted when the engine is fully warmed to get the maximum speed at idle. Then adjust the idle after you have adjusted the air screw.

The clutch issue sounds like the tines on the clutch basket get grooves worn in them. This means that the clutch plates don't seperate properly and drag a little. This gets worse over time but can be solved by filing the grooves down.

3/4 down this page - viewtopic.php?f=14&t=3484&st=0&sk=t&sd=a

[delvey91]

Nope my clutch is absloutely fine, dosent have any creep on it at all and clicks into gear without hassle everytime. Im talking about of sort of a buuuurrr noise. If im rolling up to a stop and in 2nd as i pass through neutral into first it goes ding ding ding burrrrrrr ding ding. Sort of like that anyway, As soon as it passes neutral, I thought it might be something to do with the electrical system as its in time with the neutral light flashing on as i pass down through 2nd to 1st?

[knackeredMk1]

It's most probably then just the sound of different gears working against each other. You may have some wear on the teeth which would make this noisier.

It is nothing to worry about unless it is loud.

Other opinions .

[fallenmikethebike]

More than likely it's the Active radical, doing it's bit, ie, going on lean burn mode, they run on virtual fumes at tickover, so very weak mix, which inevitably, leads to the somewhat erratic tickover.
I don,t think I have heard one, that ticks over like earlier mks.
Other symptoms are also a pulsing type tick over.
Mike

[AlanH]

Mike's right. AR's do that on tickover and it's quite normal. As for the gear thing, they have different ECU maps according to gear so maybe it's the map changeover that causes the difference?

[Active Rascal]

OKey Dokey cheers guys!! Can I confirm, the powervalve setting and idle screw should be altered when the bike is runnng warm? And the mixture screw (actually on carb) is 1 3/4 turns out and can be done anytime? Cheers. :D

[fallenmikethebike]

OKey Dokey cheers guys!! Can I confirm, the powervalve setting and idle screw should be altered when the bike is runnng warm? And the mixture screw (actually on carb) is 1 3/4 turns out and can be done anytime? Cheers.

Your assumptions are correct.
Having owned an AR, I was always nervous of that, running lean/ running out of fuel, note,to the engine when ticking[ erratically ] over.
With the seat off, you can actually hear the vacuum valves working[ clicking sound] and the engines pitch, and RPM will alter.
I fecked about with mine for an age trying to get an even beat to the Tick over, without success.
I was also nervous of constant throttle opening riding, i,e, dual carriage ways, to such an extent, every couple of miles would have me reaching under the tank for a little blip of the choke, which, fortunately is easier to find on the AR than other Mks.
Mike

[knackeredMk1]

The mixture screw = air screw and although stock is as you say this might not be quite correct and shuld be adjusted when the engine is running and warm.

[Active Rascal]

This may sound stupid, but I haven't adjusted the air screw when the bike is running, just gone by the book. What exactly are you looking for when adjusting? Is it the point at maximum revs?

Cheers for your replies fellas!!

[Active Rascal]

PS the irratic idle is quite noticeable, a few people have commented and it didn't do it before. The best way to describe it would be if you were to flick the kill switch on and off fast every few seconds (almost as if the bike engine has cut for a second in every 3 or 4).

[SkidMark]

This may sound stupid, but I haven't adjusted the air screw when the bike is running, just gone by the book. What exactly are you looking for when adjusting? Is it the point at maximum revs?

Cheers for your replies fellas!!

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