1.1 idle problems

Hi looking for a bit of advice or help with this,

My 1.1 has always run great since I got it but recently upon start up it won't idle properly and loses all revs and cuts out, a lot of choke helps a little but still sometimes even with choke out it just loses all revs and cuts out, adjusting it doesnt really make a difference, i think this only seems to happen when I engage the clutch though but I'll have to check that. 

Once warmed up it runs better but still idles a little low but doesn't cut out or anything. 

I haven't really got around to checking it out yet, was going to adjust the idle screw and check all wires pipes etc are connected on the carb and check jets aren't dirty etc but any advice on what to check or what might be the problem would be great?

Cheers 

You'll probably find your carb just needs stripping, cleaning & rebuilding. Follow the instructions as per a Haynes manual and you can't go too wrong.

Okay cheers for the reply, I'll give the carb a good clean and see how it goes. 

It's strange because its usually fine upon start up but shortly after if I move off then depress the clutch it loses revs and cuts out then doesn't idle right so hopefully that is just the carb needing a clean

check your idle cut off valve is working properly

Right I've taken the carb apart now and cleaned it all out, it's made a slight bit of difference but not much really.

Upon cold start up it runs with choke out but still when you move off slowly then brake and clutch it still loses revs and cuts out while the choke is still on.
Up at temperature it will idle okay with a tiny bit of choke (still isn't idling well though but doesn't cut out), too much makes it slowly loose revs until it cuts out and if I take choke fully off it cuts out too. 

I've tried adjusting the choke cable on the carb but with no real effect. 

I did notice a spring on the side of the carb which wasn't attached to anything and looks like it rests up against one of the throttle levers on the choke cable side, there is also a hole in this lever which the spring might fit into? Annoyingly I forgot to take a photo of it when I had the carb apart but I'll try and find one somewhere.

dan_73 said

check your idle cut off valve is working properly

Yeah i did wonder about this, Is there anyway to check if its working or not? 

Any more ideas? 

Thanks
Ned

with my ignition on if i disconnect/connect the wire to the idle cut off valve it makes the clicking noise so my guess is that it's working alright?

anyone know what else i could try or what the problem might be?

Hmm, I don't think I can help but it sounds like it's being starved somewhere.

I'd remove, replace, check, check again and just tinker until I rule everything, but the carb, out.

Mine had an idle problem once due to the carb mount - is the clutch cable free moving and not pulling/trapping anything?

Well i think it's definitely running too rich as soot on exhaust and plugs and that rich exhaust fuel smell too, carb must have been tuned a bit to get through mot as failed on emissions, but was fine after that. I thought that maybe air was escaping somewhere so replaced all rubber fuel pipes, from metal lines to pump to carb including new air and fuel filter, and also new carb gasket and made a couple new ones for the manifold to mount etc, the previous owner had an aluminium mount made to replace the rubber one so thats fine. Clutch cable is fine too.

It has made a difference and is running better now but it still isn't quite right, at idle with the choke all the way in it will die, with it slightly out but without choke light on it idles and doesn't die but the revs go up and down, doesn't sound right and isn't smooth at all.

I can start it fine with choke and run but then all of a sudden will conk out when clutch in and no revs, even though the choke is still the same as when i started or how it was running fine just before it decides to die.

i haven't replaced the plugs yet, only cleaned them up etc so going to replace and see if that helps.

but anyone got any ideas? it's getting very frustrating now thinking it's fine then coming to a stop and it conks out with no warning!

would any of these symptoms point to the ignition timing being out? thought maybe that could be the problem?

Cheers

What about the brake servo?

Mine has a pipe that comes off the rear of the engine. If its not connected properly it can cause it to just splutter and conk out (I found this out when I forgot to put it on, on its first start up!).

You've probably checked it though  

just checked and pipe to the servo is all connected and everything appears to be fine, but i noticed that when i put the carb back on yesterday i forgot to connect up the pipe to the vacuum advance on the dizzy  

connected it back up and going to go for a run later so fingers crossed thats all that was wrong yesterday!

going to get some new pipe though and replace this as it looks a bit worn and cracked

cheers