OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Ryobi Trimmers & Brushcutters Grass Scorpion RST285a Tuning guide

Hi Bruce
Chasing some info on tuning the line trimmer after replacing the carby kit.
Can you help me with anything?
Anttman

This is the procedure i use for my chainsaws ,

Turn the low and high speed adjustment screws out 1 1/2 turns adjust the
idle screw , then slowly turn the low speed adjustment in until the engine
starts speeding up then open it back out a little until it slows back down a
little, now adjust the idle for preferred idle speed ( chain should not be
turning)

Run saw up to wide open and turn in the high speed adjustment until the saw
runs at full speed then turn it back out a little so the engine sputters a
little DO NOT run it wide open for more than a few seconds.

To verify the low speed you should be able to pull the throttle in all the
way and it should not die, if it tries to die open the low speed slightly
and re-adjust idle if necessary.

anttman,

Did you replace the fuel filter screen i n the carby as well?

Tuning the carby is the nearly the same as what gmax posted.

Both screws should be bottom out lightly and then back off the "H"screw 1 turn and the "L" screw 1 turn then start the machine and adjust the "L" srew till it does not hesitate then after that you adjust the "H" screw until it peeks then back off 1/8 turn.

Hope that this helps.

thanks bruce and gmax for your replies
i tried.....god knows i tried. ive got a left hook like you wouldnt belive from pulling the start cord for so long
in the end it was off to the local repairer who kindly offered assistance and got it running
he also did say to check the needle and make sure it was clean however i think i bent the rocker arm that lifts that needle
how straight or bent should that arm be?
the problem being that now i cannot get the engine to idle at all
the guy at the shop mentioned i might have a idle problem as he couldnt get the idle to run smooth
i can run it enough to do the edges but it wont idle and stay running
suggestions?

anttman,

We have the information on carby setup in the Brushcutter parts list and manuals area. It should help a lot regarding your problems.

thanks bruce
no access to this area yet????
cheers
anttman

I cant access it either?

You only have access to the lawn Mower parts list and manuals area as that was the area that you were interested.

In order to get access to the area you want, you need to make a donation to the forum.

thanks bruce
in the end i ended up changing the gasket kit and a new primer bulb. a bit of fiddling and tuning and its going ok at the moment.
thanks for your help.
btw
here is a couple of pics of the piston out of the mother in laws rover/briggs and stratton 3.5hp.
tell me what you think....could this be why it wont start?

http://members.optuszoo.com.au/anttman1/IMG_3236.jpg

lol

not to mention the crack in the side of the engine casing!

anttman,

The reason for the damage is lack of oil in the motor over a period of time. What would have happened would be the conrod breaking and going through the side casing as the crankshaft is spinning at around 3500 RPM.

anttman,

I agree with Victaman about what happened with the mower.

Thanks for you help Victa Man.

hey guys
i think it has something to do with the two screws holding the conrod head to the crankshaft only being 'finger' tight....
yer there was oil in it....its now all over my back patio...dammit.
anttman

ps the joins where the screws link the two halves of the camrod head together show signs of excessive rubbing over a long period
was just amazed to see the extent of the damage ...especially to the other components inside the casing

anttman

anttman,

That is all signs of lack of oil. You will have bits of alloy on the crankshaft as well.