OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Two Stroke Trimmers & Brushcutters Kawasaki KLB26A cutting out

I have a 2002 model Kawasaki KLB26A ( which I have owned from new) which is starting to have some issues.

It starts first pull hot or cold perfectly and settles to an idle after a brief warm up.

The issue started a few months ago and has gotten worse in the past month. It runs nicely cutting on the flat or on its side when edgeing. The issue occurs only when cutting on the side and flipping over to flat cutting. A few seconds after tipping it over it stalls. It then restarts first pull and I continue on.

Pretty much happens everytime.

What has added to the problem to make me investigate it is it now stalls when idling if I put the machine down for a brief period, say to open and walk through a gate. The idle gets lower and lower until it stalls.

I pulled the carby down a few weeks ago and the internals were spotless. I also replaced the rubber grommet into the tank and upon inspection the tank was also spotless. I am anal with my equipment and refuelling.

I also changed the aircleaner and the spark plug just on hope. This arvy I pulled the muffler off and the port was also spotless. It was the first time off in 10 years. The piston and barrel looked unmarked. The machine has very good compression.

The only thing I haven't changed is the fuel pickup. I'll do that though.

I should add that I didn't change any carby gaskets?? Maybe?

Any ideas?

It wouldnt hurt to put new gaskets and diaphragm in the carby, after all, they do deteriorate over time, and its deftinately worth replacing the filter in the fuel tank while doing so to be certain that your new gaskets are not going to have dirt get into them anytime soon.

Personally I would look at the carb gaskets, make sure the little needle and seat gets checked while doing that also.

There seem to me to be two important clues here. First, it is position sensitive, so the air fuel ratio is changing when you invert the engine - position can't change spark or compression. Second, it works properly at full cry, it only goes wrong at idle.

My first guess, given those symptoms, is a split fuel suction hose inside the tank. I've had it myself, long ago, though mine was worse than this sounds (1/2" long split, right where some clown had made a mess of installing the hose with pliers). Usually, a split suction hose will prevent the engine from starting rather than kill it at idle. It will also usually be sensitive to the amount of fuel in the tank: pretty reliable with a completely full tank, and decreasingly reliable as the fuel level falls.

I don't see the carburetor as very likely to be position sensitive - but I may be wrong.

Appreciate the responses. Today I changed the fuel line and the intank filter and got no change to the running characteristics.

I put a new carby kit through in and the machine is back to it's best. I changed the needle, carb to aircleaner gasket, carb to head gasket and two gaskets internally.

I don't know the terminology but the gasket which has a small stainless disc attached to it, diaphragm perhaps? was stiff as a board and the new one is very flexible. Perhaps the culprit?

It's running beautifully and the parts which I changed, eg fuel lines were really due after many years of service. They were no longer soft and pliable.

Cheers

That would definately do it, thats the fuel pump diaphagm, once they go hard they never work again properly. All in all a great result

As your problem is sorted I will lock this one up, if anyone wishes to add to this thread pm a moderator and one of us will unlock it.

Topic unlocked as per original posters request.

Thanks Joe.

Not having the need to use this unit lately, I pulled it out last week and the same problem presented itself. I guess after the reassemble of the carby there was a chance I did not get the machine to operating temp. I don't know but it's back to it's same tempermental self.

Just a thought before I set a match to it, the side I rotate it to for edgeing has the fuel cap down, could it be causing the problem? Not being able to vent through the cap?

In theory it doesn't make any difference to the tank venting, since it is just sucking air in through the valve in the cap, and bubbles just rise through the fuel instead of entering above the fuel. If you suspect it is a tank venting problem, just try it the right way up, with the fuel cap loose. If it runs better that way than it does upside down with the fuel cap tight, you might try inspecting the air valve in the cap. I've had them stick due to oxidised oil, when the machine is out of service for a long time. If the valve is stuck just wash it with petrol, holding the valve open while you do it.

have you checked the obvious that when on its side, the filter on the end of the fuel line is sucking air? try it with a FULL tank and see if it still happens