another idling problem question!

[icenian]

Have a problem which doesn't seem to correspond to any of the many earlier threads on idling problems... (unless I missed somehting, there's a lot of discussion on it!)

Idle is OK on the choke - normal fast idle at about 2500rpm. But when the engine is warm enough that it should idle without choke (maybe 10 seconds at this time of year) it won't idle. Mucking about for a couple of minutes either with the choke open or using the throttle to keep it going, I can get it to idle, but only very slowly and erractically. Running a lower revs (<3500rpm) seems a little rough but not too bad.

This is what it did when I had a blocked pilot jet.

But at the moment, when it's properly warm (say 5-6 miles riding), it's completely back to normal. Idles and smoth right through the revs. I can't seem a blocked jet ceasing to cause problems with a warm engine. Or a stuck choke being less of a problem when the engine is hot.

Can blocked jets be intermittent? Or can they get partly blocked and just show up with a cold engine?

Oh and opinions on whether stuff like Redex actually works would be welcome!

[africatijn]

Hi,
Not too much into carbs, but have you tried the obvious things as draining the carbs, checked the air/fuel filter etc?

Cheers,
T.

[icenian]

Hi,
Not too much into carbs, but have you tried the obvious things as draining the carbs, checked the air/fuel filter etc?

Cheers,
T.

Confess I was going to consult with you guys before I actually did anything

Also gives me an extra couple of days to use some fuel, so trying to lift a full AT tank off doesn't give me a hernia

But yes, those would be on my list. Though I doubt restricted air or fuel flow would cause idling problems with an engine that ran well at higher revs?

[robelst]

Hi,
Not too much into carbs, but have you tried the obvious things as draining the carbs,

I agree, maybe just a few moving waterdrops intermittently playing up? Easy enough job to do (easily accessible drain screws / hoses), just don't forget to close fuel tap
Otherwise air-leaks (carb rubbers) are famous for inconsistent behaviour of idling.

Good luck!

[YEN_POWELL]

Choke cable sticks after first use causing problems when first warmed up. Later on the vibration and heat makes it slowly move into the off position until next time it's used when the cycle is repeated. To test, wait until it is running properly at idle when warm. Next day start the engine without any choke. See if it is fine when warmed up.

[africatijn]

Hi,
Now I remember... I had the same once. Idle running was very unstable, and when releasing the throttle, returning to idle took a long time. In my case a carb to inlet rubber was loose, the metal clamp was just dangling around the rubber.

I'm told that if you drive for a long time, this can harm your engine, because the mixture is far too lean (due to the false air being sucked in).

The fuel economy is very good when this happens....

Gdluck,
T.

[Blues N Twos]

I have just solved my rough running. It was ok at lower revs but rough as a dog in the mid range. The spark plugs on the front cylinder were very sooty so I looked at the choke cable and gave it a good squirt with penetrating oil and it seems to have done the trick.

Also my airbox wasn't sitting on the carbs properly. I started this morning with no choke and it ticked over fine after holding the throttle open at about 1500rpm for a few seconds. You can actualy get your hands under the tank to access the choke cables to lubricate them. I took the tank off but thankfully I was already on reserve.

Jon

[icenian]

This problem came back But I seem to have fixed it

Plugs in the rear cylinder were pretty black. I detatched the end of the choke cable on that cylinder, and it didn't seem to bad, but spray of WD40 to clean it up seemed to make it work better. It wasn't rusty, but I think someone had greased it heavily in the past and that had dried and/or got dirty??? Anyway, I got it moving more freely and popped it back in.

Started up and idled nicely cold, warmed really quickly and ticked over smoothly without choke.

Drained the carbs whilst I was guddling about in there. Swore at Honda for having carbs which were (for a Honda...) fairly accessible, but where you couldn't reach the drain screws. Then realised you could just reach them at a wierd angle. So long as you have a screwdriver of the exact right length. Which of course comes in the tool kit...

Anyway... what's the knack for getting the choke cable unscrewed, without taking the carbs off? Utter utter utter b*st*rd job! You can get about 1/12 of a turn with a spanner, which clearly isn't going to work. Luckily I could get the spanner on and that 12th turn loosened it enough for me to undo it with my fingers.

Some thin pliers with a 90 degree bend at the end might just get in there, but that's a bodge, and begging to knacker the nut.

If you could an a tool made like an 8mm open ended spanner with a 90 degree bend at the end, that'd do it...

[YEN_POWELL]

You did have the tank off didn't you. I have discovered that if you actually first put the choke on at the handlebar end, all the pressure from the spring goes away and you can do the plastic nut up or off nearly all the way with your fingers. Finish it off with an 8mm spanner at an angle.

[icenian]

Yes, tank off (can't imagine trying to do it with the tank on...)

Thanks for the tip about putting the choke on, will try that the next time I (inevitably) have to do it!