400 Four Idle Problems

[Piki]

Hello Folks, I need your advices....Yesterday I "run" my 400 four after one sleeping year in the garage. 4 or 5 kicks and alive again, I take a short ride and all worked perfect but  when I stop in the Traffic Lights, the idle is up and I have to turn the idle screw down, where is the problem??
Thank you in advance.

[mike the bike]

The petrol goes off after a few months and turns into a cough-mixturey goo that blocks jets up.  Unless you drained the tank and the float bowls before you put the bike to bed, this sounds like the most likely cause.
An hour or so of stripping and cleaning should make a difference.

[tom400f]

What product do you use Oddjob?

[Nurse Julie]

Hi Chaps.
I don't think it has anything to do with the petrol if it started after only a few kicks. I have the same problem with the idle on my 400/4 but I'm doing quite a few miles on her at the moment and filling up at least twice a week. I think it's the carbs that need a bit of fine tuning in my case. I also saw someone start a CB750 K6 yesterday that had been sitting idle in a coal shed for 6 years and it started after about 7 kicks on the original fuel.

[mike the bike]

What sort of coal was the bike running on?

[Nurse Julie]

Smokeless Mike 

[Johnwebley]

interesting thoughts,

 lately a lot of the sohc have been having idling issues,

 would this be linked to ethenol ?? is it making the slow running more critical?

 just a thought

[Piki]

I do no think that problem is the Fuel... Is possible that "piston slides" from the carbs , not return properly??? When the bike is on the Center Stand the idle is great.....

[Lobo]

I too use a petrol 'preservative' (again, garden centre type outlet); keep the tank(s) full to minimise condensation / rust .... & to date never had a problem with any of the bikes fuel system wise.

Lobo

[mike the bike]

Most likely the pilot jet emulsion tubes are blocked

[exvalvesetdabbler]

I have used fuel preservative for storage over  a good few years  now and more recently, regular use of one that provides protection against corrosion due to the effects of ethanol in the fuel. Currently using Miller's EPS so only time will tell if this if worthwhile.  I just keep about 10ml in a small minature glass bottle in my pocket and dose the tank when topping up.

http://www.millersoils.co.uk/pdf/automotive/Ethanol%20in%20Fuel.pdf

I have also noticed that fuel mixture is a bit leaner on modern fuel , particularly since replacing emulsion tubes and main jets with new OEM parts from DS. Previously the corrosion(and probably 30 years of wear) had enlarged the top of the emulsion tube causing over rich running.  My pilot air screws are currently about 1 to 1 1/4 turns out to give smooth transition when rolling on the throttle at low rpm.

Modern fuel does seem to go bad quite quickly, even if a preservative has been used some of the 'goodness' seems to be lost over storage. After winter storage, filling the carbs and then draining again is necessary to get some good fuel in them , makes starting much easier.

We certainly never had these kind of problems with 2 star fuel when I were a lad.



Dave

[Piki]

Great info exva!! where can I get it, I live in Spain..........could I buy it on Ebay?
Best Regards.

[Chris400F]

There are a number of 'fuel preservative' listings on eBay (UK) but you will pay quite a bit in postage if you order from the UK.
Probably worth looking to see if there is anything similar available closer to you.

[exvalvesetdabbler]

Another local source of fuel stabiliser may be anywhere people keep leasure boats, marinas, chandelrys etc , or garden machinery suppliers.  Just make sure you get one specifically for ethanol blended fuels.  Some of the older fuel stabilisers  already have ethanol in and can make corrosion problems worse.

Stabil is another brand  to look out for and seems popular with the boaty types.
http://www.goldeagle.com/product/marine-sta-bil-ethanol-fuel-treatment-stabilizer.

Most of the better brands come from the US because they have had to put up with ethanol in thier fuel longer than we have here.

Dave