OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Ryobi Trimmers & Brushcutters Ryobi Weed Ranger 31 cc tuning

I have one of these with a Walbro carburettor. I used it once about 5 years ago. Everything is like new. I am now trying to use it again. It has different ideas. It did not want to run, and now won't run properly. I have given it a new plug, new fuel with Stihl 2 stroke oil, dismantled the carburettor (all clean as a whistle), ensured the vent valve in the fuel cap is letting air in (it wasn't) and find it runs just as well on half choke as no choke, and I simply cannot get full revs. I have improved it a little by moving the 2 spring loaaded plastic screw heads (one white, one black) but only marginal improvement. I have them both fullly out at present (but they are only adjustable about half a turn. What else can/should I do?
(PS Bruce, you look like a saint from what I have read, and thanks for the welcome)

Doug,

The plastic on the high & Low screws can be taken off so that you can correctly adjust the carby. Refer to the carby setting on this forum and you should be ok.

If the adjustments don't work then you will need to replace the diaphragms in the carby.

Thanks Bruce. I assume the white is the H and the black is the low? I also saw something somewhere which suggested they were set rich for running in, and mine is certainly not run in yet (assuming it needs it.)
I will try and find carby setting on the forum.
Cheers
Doug

Doug,

The screw closest to the cylinder is the low speed screw and what I would do is remove both screws and clean the holes out then replace the screws and bottom out gently.

Then back off the low screw one and a quarter turns and the high screw one turn. The machine should start and then set the low screw so you get a good response when you throttle up.

When that is good then start to adjust the high screw till the machine peeks then back off 1/8 turn.

Thanks Bruce and Victa Man

I have now removed the plastic bits from the screws - the settings as delivered by Bunnings were - low: 1.5 turns off seat, and high: 4.5 turns off seat.

Have now tried to start it, on the new settings, and nothing. Except a fine pair of blisters on my fingers. Tried to start on original settings - will run briefly on full choke but dies. Removed plug and blown it with compressed air. Nothing. Clearly has spark.

Although about 5 years old, this machine has been run, from new, for less than 30 minutes, never been wet etc. (I bought it new).

Not impressed. Once I cool down - it is warm and humid here today, I shall go to work.

Any further tips?

Doug,

Can you check the exhaust port by taking off the muffler and looking for carbon build up.

While the muffler is off try starting the machine and if it runs then it could be a blocked muffler or screen.

Also while the muffler is off check to see if you have any scratching on the cylinder or piston.

Let us know what you find and then we will go a bit further.

Bruce, you are a legend. As usual, I have learned heaps about things I didnt need to understand.

On removing the muffler, it was as clean as a whistle, visually. No carbon as it had only run from new a max of 30 minutes.

However, on trying to blow compressed air out the exit hole (spark arrester removed) I couldnt. Nothuing visible, but on poking a screwdriver in there, hard, some dirt came out. A !@#$%^&* wasp had built its nest in there.

All now well, and I now know how the carby is made, what screw does what etc.

Many thanks to all who helped in solving this problem. I shall make a donation.

Cheers

Doug

Donation made.
Doug

Doug,

The wasp nest in the muffler is very common especially if you are near rural areas or bush. I have come across that a few times in the workshop.

I am glad that we helped in solving your problem and now all the other members of the forum will have a better knowledge base.

You know, it was the first thing I looked for, but it was simply not visible, even with the spark arrester removed - I assume that is what the thing which screws over the hole is.

The litle blighter built it right up inside.

I must say what a lovely bit of engineering the carby is. And I imagine performance could be inproved even more by reducing the surplus thread on the screws holding the butterflies for choke and throttle - or even going to countersunk screw heads.

Doug

For the benefit of those who have the same problem I did, with the benefit of hindsight,


1. Remove small cover over exit hole in muffler

2. Locate the whole unit so the hole is facing down - eg on a small workmate bench so you can access the hole from underneath (this is important as otherwise any loosened rubbish could access the exhaust port and damage piston/bore

3.Push a long skinny screwdriver up there as far as it will go and move it around ensuring any loosened rubbish falls out.

Estimated time to completion - under 5 minutes
(Time spent learning this is the easiest way - 2 hours)

Doug,

Thank you for posting how you fixed your whipper snipper and I am sure that all the members of the forum will appreciate your advice as I do.

If we had more people like yourself explaining how they got to solve their problems this forum would be a wealth of knowledge.

Thanks again for your support towards the forum.

Bruce

I could't have done it without your suggestion to take the muffler off. Even after removing it and examining it it appeared fine - it was only when the compressed air wouldn't go thru that I smelt a rodent - or, more precisely, the insect's home - that the solution became obvious. I was about to start checking the magneto, which would have been a whole new can of worms.

So, thanks again. And the best 10 bucks I have spent in a long time.

Cheers

Doug

Thanks Victa Man, this was a great help