Ryobi 725r Idle problem

Old 07-20-04, 09:12 AM
Visiting Guest
Posts: n/a
Angry Ryobi 725r Idle problem

I was given a used but look brand new Ryobi 725r - 2 cycle - 31cc trimmer. I am sure that it has good mixture of gas and oil. Filter is very cleaned.

It starts fine but when I move the choke control to full choke, its starts and cut off. When at Partial Choke position, it starts with loud noise. When move to Run position, it is even louder. Squeeze the throttle, engine revs up a little bit.

I tried to adhust the Idle screw but when look at the mechanism, this Idle screw is not serving anything.

1) The manual says when in Run position, engine should be idle but my revs up at very high RPM. What is wrong with mine? Is my trimmer correcly set?
2) If not, what could be wrong and how do I fix this problem?

Old 07-20-04, 10:12 AM
Visiting Guest
Posts: n/a
If your idle speed screw does not come in contacts with anything, is your throttle cable connected to the carb? Pull the trigger and observe the arm on the carb for movement. If you cable is intact but no movement (or tries but wont move) your butterfly may be stuck. As for adjustment, the following is from another post and is for my 790R but should get you in the park.

You should have 3 adjustment screws, 2 side by side and a 3rd that sets your idle speed, the 2 side by side should have plasic caps on them? If so did you remove these to soak the carb? Any info I have gathered for initial settings has differed greatly between manufactures even when using the same carb type. And the Ryobi site is down at the moment so I am refering to my manual for my 790R but should get you going. Idle setting, this will be the screw off on it own that when turned in(clockwise) opens your throttle plate. Screw this in until it just comes in contact with the plate that opens the throttle, then continue 2 turns for walbro 1 1/2 turns for zama.
If the plastic caps are still intact on your mixture screws and have not been deformed or turned past the stops, set them clockwise to the stop. If they are deformed and or have been turned past the stops, you will need to remove them to find out how many turns out they are from seated. My manual says the initial "high speed mixture" is set at 1 1/4 turns out from seated. It does not mention a setting for idle mixture other than out to the stop, but I would think 1 turn out should get you going. If this gets it going, turn the low needle in until the fastest idle is achieved then back it out 1/8 of a turn. Squeeze the trigger and if the engine falters continue backing the idle mixture screw out 1/16 of a turn at a time until it accelerates rapidly.
Old 07-24-04, 08:56 AM
puey61's Avatar
Join Date: Apr 2004
Location: Upstate New York
Posts: 3,224
Received 0 Votes on 0 Posts
Any luck yet with your Ryobi troubles?

Thread Tools
Search this Thread
Ask a Question
Question Title: