idle

[pricey797]

hi all , quick question my mk1 125lc has problems idling sometimes 2000 sometimes 1300 and even as low as 800, when its idling at 2000 if i squeeze the pipe to the yeis bottle rpm comes down to normal before tailing of around 800 to 1000, i have taken pipe off bottle and blocked it with a bolt and she idles perfectly at 1300 all day long , i have also taken bottle off and checked for holes splits but nothing visible , any ideas what else may cause this.

[johnlc]

Try spraying easy start around any air tight joints revs will rise if anything is leaking

[pricey797]

tried that , no change in rpm

[johnlc]

What reeds are in there I had problems with fibre reeds

[pricey797]

i think there are fibre reeds to be honest what would you suggest

[johnlc]

When I had them I had oroblems getting revs to settle changed to steel and it was fine , what's it like easing off the throttle down the gears

[pricey797]

runs ok to be fair , wont hold high rpm in 5th and 6th,bu ti aint no racing snake lol

[jackup]

Sounds like the reeds are sticking
Take the reed block out and clean it if reeds are ok

[pricey797]

should i go back to metal reeds or buy new fiber ones

[johnlc]

How old are the reeds

[pricey797]

no idea were in it when i got it 12 mths ago

[dex46]

Hi mate had the same problem on my Mk1 which I have only just purchased its a full 12a fitted with a 10w pipe all I done was stripped carb gave it a full clean with carb cleaner checked all the jet size's and setting's found the needle position was on the bottom clip moved to middle position as mentioned before CHECK reeds mate mine is fitted with fibre one's found they are warped and they was leaving a 2mm gap turned them around and they are fully closed now bike now run's like a sewing machine my set up is
Standard airbox
10w pipe
200 main
20 pilot jet
Needle position on the middle
1 and a half turns out on air screw

[pricey797]

thanks fo rreplies people but i think its a little more than carb and reeds i topped water yesterday went for a quick blast down road to find my left foot soaking wet , water blowing out of header tank so think maybe head gasket has gone, not sure but maybe this is not helping matters

[Deleted]

head gasket gone very possibly but its also easy to put the head gasket in the wrong way (yes I've seen it done!) round blocking the water ways causing a pressure build up.
the other cause could be not torqueing down the cylinder head nuts correctly, blocked pipe ways etc etc.
thing to do is check the head gasket and cooling system pipe ways and eliminate each possible fault one by one until you find the reason