OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Two Stroke Trimmers & Brushcutters Bushranger line trimmer bogs on full throttle

Hi everyone. My Bushranger line trimmer bogs down when on full throttle. The only way I can get my line timer on atlest about 70% power is when I have the throttle about half way open. Please I need advice on how I can get it sitting on full throttle putting out full power.

Pull the muffler off and check the exhaust port,it is probably half the size it should be. Make sure the piston is up before you start digging the carbon out and blow it out before you move the piston

Norm,

I just wondering if you tried ever soaking these engine ports and the cylinder chamber with de-carbonizing fluid? I know it works on Stihl handhelds that are completely seized up by carbon. On several hours and application refills those engines start to free up to where they will start. At first they start and run poorly belching lots smoke as the carbon then burns off. This smoking will start to clear and engine operation will start to improve until all the carbon and de-carbonizing fluid burned off.

Here the Stihl de-carbonizing fluid is hard to get so I use the AC Delco vehicle de-carbonizing fluid.

On stuck engines you do have to make sure they weren't straight gassed first.

Hi AVB,
No I have never tried soaking them to remove the carbon, I usually have the bloke standing beside me wanting his machine back as quickly as possible

Hi Koii ,Norm ,AVB
If the exhaust isn't blocked.

It may just need a tune.Mixture screw adjusted ( the H screw)

After checking the basics

Air filter: clean or replace if dirty.

Fuel: fresh petrol, correct 2-stroke oil ratio.

Fuel lines & filter: no cracks or blockages.

Spark plug: clean, correct gap

Then adjust the High-speed screw (H) → controls full throttle mixture turn anti clockwise to make the mixture richer

How to use it:

Focus on the H screw to fix bogging at full throttle.

Adjust in 1/8 turn increments.

Check engine response at full RPM after each adjustment.

Once smooth at full throttle, fine-tune L screw for idle and low speed.

If that doesn't fix it ,sometimes as you try to rev out the motor with air filter off you can spay a little extra fuel or
starter fluid int the carby if it revs out you know it's starving for fuel.

There is a test here to check fuel filter , primer and fuel line problems here https://www.outdoorking-forum.com.a...l-fs36-died-at-full-revs.html#Post122085

If that doesn't work it may need a carby clean and kit or new carby.

Cheers
Max/

Max, I do forget that some posters are not knowledgeable about equipment.

And Norm those types of customers here pay more if they are that big of rush. But in your area some has to drive a long way if I understand the area correctly.

Hi AVB,
Yes I do get some people from a fair distance away. Last week I had a bloke drop a Deutscher ride on here he wanted me to repair. He is from QLD 1700ks away. Sure he didn't drive all that way for me to fix it , he had other things he had to do down here and he hopes to get back here to pick it up at Easter. I said to him he was insane but that didn't phase him. Time will tell if he ever comes back. I have put a new motor on his ride on so no problems selling it

Hi everyoneone. Thanyou all for the suggestions. Ill take into consideration and try them all.

Hi Koii, just do one thing at a time

Just a couple notes on adjusting the fuel mixture.

First the low and high do interact. So it is to get the idle mixture right first. IF were an Echo trimmer I could provide basic procedure but you must have a tachometer. It is that you tune to best speed and then enrich to slow down some. Then you peak the high and then enrich for a 100-150 drop. From there you fine tune for throttle response.

Second the metering lever should be set at the correct height or you have over rich or lean out. Similar a stiffen metering diaphragm can cause problems. This why I have three different metering lever tools for Walbro [2] and Zama [1]. Many of the Ruixing carburetors uses one of the three depending on which carburetor it is a clone of.

Basically this interaction is the same for all carbs as the idle mixture feeds all the time.