Honda S-Wing with unsteady idle

[furstyferret81]

Hello all

Recently noticed that when my S-wing is idling the revs jump up and down slightly by 100/200 revs? Anyone know if this is normal or something of concern?

I also find the scoot rather slow (65 indicated), slightly faster top end than my PCX but not by much and acceleration slower. I put new rollers and air filter in but nothing changed. Bought it with 10k on and now its at 14k, i was going to put a new belt on early but i was thinking it could be something to do with valves or the injection system or maybe its all normal?

Any suggestions are very welcome before take it to a garage!


Thanks

Ben

[michaelphillips]

i would pop in a new ngk iridium spark plug first, as you have changed the air filter thats ok... and if no better then the valve tappets need setting anyways at that mileage, the injection system should be fine, but you could run some redex though it, just one quarter bottle on each fill up, will clean the injectors

[Globs]

Yup - try a new plug first.

[furstyferret81]

I put some Redex in already. I changed the plug about 6 months ago and noticed the the gap on the old one was probably double what it should be?!? An iridium one could be an idea.

Dont think ill attempt valves myself after all the fun i had doing it on the PCX!

I'm avoiding spending too much on it as i'm still contemplating a Joymax 300, but i'm worried if i don't look at it ill cause some damage.

[Data]

fursty, did you get the air filter seal to seat properly? It's not uncommon for this to leak a little and this affects the fuel mix even at idle and will cause a slightly uneven idle.

[MrGrumpy]

Has your top speed always been 65, or has it declined recently? A reduced top speed is a classic symptom of a worn out drive belt, and I presume yours is the original, so could well be in need of replacement after 14K miles.
You may have minor engine troubles as well of course - a varying idle is rather odd, but not my area of expertise!
btw its another snag of a 125 - you really notice any minor problem or worn belt as each mph of top speed is precious!!!!

[furstyferret81]

It was doing it before i changed the air filter and it didn't help any. I don't really know much about mechanics but on my old car i cleaned the butterfly air valve thing behind the airbox and it ran so much better, would an injection scoot have this too?

[smeghead]

The Majesty I had used to flutter a bit at idle, it even cut out a couple of time at traffic lights. I put a Brisk LGS plug in it and it cured it. If you can get one to fit I'd give it a try.

[michaelphillips]

your lucky your honda uses a standard plug , the iridium is CR8EHIX-9 with a .9mm gap which is a larger gap than standard... check the gap as you may have it .7mm or so which will not spark well.
and definitely get the drive belt cover off to have a ganders as a worn or splitting belt may be sticking in the variator. i would have thought the swing plastics would come off better:0
you should be at 9000 rpm at 60 mph so as a guide

[Fatblokeonamoped]

My top speed is also around the 65mph mark, always has been, I wouldn't have thought that is an issue. It's Vmax, downhill with a following wind is 70mph at 10,000rpm - where it will hit the rev limiter. I'm just coming up to 15k miles and have had the bike since 73 miles, so ours are almost identical in age.

I did have a problem with last year at about 10k miles whereby 9,500rpm was 65 as was 10,000rpm - I kept hitting the rev limiter!! As mentioned by someone else above, a belt change solved the problem.

I've never noticed if mine hunted on tick over so nipped downstairs to try it. Mine is rock solid at just under 2,000rpm (with an iridium plug, Leo Vince exhaust and Dr P sliders), so i can't help you there.