uneven idling yanclone

[arnaud]

..my new, second yanclone idles uneven.. at even lower rpm's it is even again, when opening the throttle slowly it starts to run uneven again..
anyone a clue?

[alexanderfoti]

What RPM are you trying to Idle at?

[arnaud]

..not too low, ca 1000-1200 rpm..
Can it be some airdrops in the fuel line?

[Diesel Dave]

It can be your max fuel screw is set too rich, can you measure the gap between the arm and the plunger tip or is it trapped between the motor and gearbox?

[alexanderfoti]

It should run OK at that speed. Any chance of a video?

[arnaud]

It can be your max fuel screw is set too rich, can you measure the gap between the arm and the plunger tip or is it trapped between the motor and gearbox?

yes but the fuel mix srew is for the higer rpm's? reducing the gap will give lower rpm output.. still running in so did not try yet..

[Diesel Dave]

Not exactly.....Max fuel operates at all speeds.

When the governor weights fall below the idle speed it allows the regulator spring to pull the injector control arm into the 'operating range'. If the max fuel screw is set too rich this causes the motor to speed up faster than the regulator can control and you get a 'Rum, Rum, Rum, kind of idle so common on plant equipment that's poorly maintained.

It will also smoke a bit due to the over-fuel injection.

Imagine trying to control a swiss watch with a 2 kilo hammer and you get the idea.

[arnaud]

Hmm i will adjsut the screw a few turns tommorrow.. wil let you know the result.. thanks!

[Diesel Dave]

Whoa - gently does it - half a turn will make a big difference of it's close to where it should be.

Usually the manual has instructions for the approx gap between the plunger and the contact face.

[arnaud]

Well, after 3 half turns- half turn at a try-, top speed was 60kjm/h, but the phenomenon persists..

[Diesel Dave]

Arnaud,

Just to confirm a few details:

It's a 10hp Yanclone running the std flywheel and operating on pump diesel.

You have checked the fuel filters are clear - run at least a litre out of the pipe that fits onto the injector (after all the taps and filters) and it maintains a constant flow.

The breather hole in the fuel cap is clear.

The regulator is std and without any mods.

BTW does the idle speed change if you lean the bike over (both left and right)

[arnaud]

Everything is okay nd std. , fuel line flows good and has a new filter.
i will try tilting the bike tonight.

[arnaud]

Checked the valve clearance to be sure, rode 60km yesterday evening to the fencing school and back..
it is strange.. it CAN idle even at very low rpm, then there's a 'gap'where it idles very uneven and when in gear it is hard to handle.. a little above that and it runs even again.
when idling uneven, puffs of black smoke is barked out by the exhaust, so i am willing to beleive it gets too much fuel..
could it be a fabric-new malfuntion of the fuel pump?

[Diesel Dave]

It's possible but unlikely....

[sbrumby]

Try taking out the injector pump and check the rack has free movement there should be no tight spots and very little force needed to move, in fact when tipped on end it should move under gravity.

[arnaud]

Thanks srumby for the tip.
i have to report another thing, i don't think it is at fault and i cannot remember it being a problem with the last engine, but the governer system has 2 springs on the outside
the small one at the 'hind'of both levers and the big one, which you place in the outer holes to get max rpm.
This spring has no tension/has play around idle position..
ofcourse, releiving this play means throttle open and rpm going up..

[alexanderfoti]

On My yanclone, I only used one spring in the outer hole. Maybe that will help?

[arnaud]

Meanwhile, i replaced the pump and the injector, still same problem...
It could not be air in the steel fuel line? i guess it would run crappy at every rpm's?
Any tips on 'bleeding'the system, and get the eventually air out of the corner of the fuel line?

[Diesel Dave]

If the max inject (max rack setting is too high), then it will 8 stroke (or even 12 stroke) when it injects at idle - it's a big volume of fuel so you get a big bang and black smoke but it accelerates the crank/flywheel way beyond the idle speed so it stops injecting 'till it slows down.

Remind me never to pick a fight with you, especially if you are a sabre expert.

[arnaud]

Dave, i did set the fuel amount back, untill it lost power altogether.. but it did not work..
Ehm, i'm an epee expert.. not a sabre fencer..

[Diesel Dave]

Dave, i did set the fuel amount back, untill it lost power altogether.. but it did not work..
Ehm, i'm an epee expert.. not a sabre fencer..

Yes I have the same problem with a Yanclone motor, I'm going to try raising the idle speed in the hope this will get it to fire every time and save the 'big bang' syndrome.

Epee eh, that's alright then as I'm good below 400 yards with a 17HMR...

[dieselbikin]

I'M having an idle problem too. The engine is currently not under any load. Governor set single large spring set on B-3.The engine idles properly when I first start it, but after throttling it up several times it runs up to about 3000 rpm and wont idle back down. I also can no longer shut it down by pulling the bottom lever away from the fuel volume adjusting bolt. If I can fix this I'm home free. Thanks

[dieselbikin]

I tried messing with my engine again today, but not having any luck. It idles correctly until I rev it up. Then it accelerates to max governed rpm and no longer responds to the throttle. Also, I can't get the engine to shut down by pulling the bottom lever all the way to the right. I'm getting frustrated. Any help would be appreciated. Finally is it a problem to shut the engine down with the decompression lever? Thanks.

[UAofE]

That is an internal injection pump/governor problem.

[bf109v7]

Finally is it a problem to shut the engine down with the decompression lever? Thanks.

Yes, Better open the fuel line to the injetor.
Alex

[dieselbikin]

Thanks.

[16VGTIDave]

Has the pump been "turned up"? If so, you may have gone too far.

[dieselbikin]

Ive tried it screwed completely out and barely touching. I've even pushed to either extreme and it just won't idle down.

[BoxerOtto]

have you, removed and reinstalled the injection pump? if so the governor fork may not be engaged properly with the rack on the injection pump making it run wild and no shut off. just a thought.

[dieselbikin]

Actually I have moved it. The lever that moves left or right under the little access panel could do this? Thanks.