Revs dying on full choke (Oil leak fixed? 12/06/12))

[missis sumner]

You don't need to set the electrode gap.

Are the carbs clean (proeperly clean) and properly adjusted? (float height / idle screw)

When did you last check your valve clerances (with the carbs off it's a good time to do)

I'd check the carbs have the right jets and emulsion tubes, reset the float heights and pilot screws, ensure the pilot circuit (3 tiny holes to the butterfly) are spotless on all carbs and re-balance.

If they and the clearnces are fine theres no reason it shouldn't run perfect.

Electrode gap - that's what I thought, ta.

I assume the carbs were clean and properly adjusted, as it was running really well. They were jetted to suit the exhaust that's on the bike before I bought it. It may be that they now need cleaning - after not having so much use over winter.

Do I need to remove the carbs to check the valve clearances? I don't seem to recall the Haynes saying so, but the guide on here does?

[missis sumner]

Ummm... how long should my bike run for with the fuel tap in the "off" position? It just seems to continue to run...

[CRM]

well it could run on tickover for upto 5 mins
riding on the road then around less then a minuite before it started bogging down.

[missis sumner]

well it could run on tickover for upto 5 mins
riding on the road then around less then a minuite before it started bogging down.

Ok - I'll try it for longer. New plugs made no odds to the choke dying down problem, but they may improve the hot idling problem, as on closer inspection I found a slight crack in the insulator of one of the old plugs. It's all back together now, so we'll see...

[missis sumner]

Ummm, new plugs DO seem to have made a difference. Starting on choke is better; it still revs quite low at first, before picking up to 3000 then 4000 - then runs fine when I reduce the amount of choke slowly, and this weekend, I've had no problems with cutting out on idle when the engine's warm.

I'll see how it goes...

[missis sumner]

Ok, so I've still got a problem when starting from cold... the bike dies down on full choke. It seems to be worse the longer it's left without starting...

...AND I have an oil leak.



So the bike is stripped down, ready for cleaning tonight, so that I can try to see where it's coming from.

Could this:



be a related problem? I noticed the oil around the base of the plug the first time I removed it, but as the tip of the plug looked fine, kind of ignored the problem... Oh, and there was a little oil in the air box, as well.

Doing some reading on here, should I be looking at the rocker/cam cover gasket, or somewhere else?

[Man_Named_Dave]

I'd start with the dipstick to see if the oil is over-filled.

[missis sumner]

I'd start with the dipstick to see if the oil is over-filled.

It's not now. I did over fill it when I did an oil change, but I removed the excess before I ran it for any time.

Also, I think the oil leak may have started before I did the oil change, and that plug was pulled out of the engine before I touched the oil. Honest.

Edit: That's not to say the oil leak is nothing to do with me overfilling the engine - just that the plug was oily before. May be two separate problems?

[CRM]

Sarah, the oil leak may be from the gear change oil seal or front sprocket seal. it will need a good degrease and jetwash to identify properly where its coming from.
my money is its from the airbox breather pipe which vents to the underside of the engine and is possibly not routed right and is pissing it all over the motor.

the oil on the plug thread is a bit more mystifying. did you run it for long with excess oil in ? ie just fired it up on the spot and revved it or actually used it on the road ? if used on the road that explains quite a lot and the extra pressure has fired it out of everywhere.

[missis sumner]

Sarah, the oil leak may be from the gear change oil seal or front sprocket seal. it will need a good degrease and jetwash to identify properly where its coming from.

...tonight's job. Thanks for the pointers.

my money is its from the airbox breather pipe which vents to the underside of the engine and is possibly not routed right and is pissing it all over the motor.

I'll take a look. I may have disturbed something when I took the tank off and opened the air box.

the oil on the plug thread is a bit more mystifying. did you run it for long with excess oil in ? ie just fired it up on the spot and revved it or actually used it on the road ? if used on the road that explains quite a lot and the extra pressure has fired it out of everywhere.

That's an old photo of the plug. It was like that before I changed the oil, and overfilled it. If I get time, I'll check them again tonight but my main job is going to be cleaning oil off so I can try to see where it's coming from.