# Echo PB 255 Carb Adjustment



## smeltjr (May 8, 2005)

4 months old. Echo blower with rotary carb rb-k70. The adjustment for the carb is 30 days, then you pay. At the beginning would not throttle up - they did a carb adjustment. Now 4 months and it is probably broken in per the echo manual whici says do final adjustment after 2 full hours use/2 full tankfulls. 
Seems a little under powered. Idle is 3300 rpm which is just above spec per manual. Max full throttle is 6900 which is 400-800 rpm low. Now question is on carb adjustment of this. I believe the high speed mixture is in an opening below the primer bulb. Then there is a "anti-tamper" plug. How does it come out and can i actually access the adjustment screw at that point? Need special tools and can anyone direct me to which specific ones?
I really do not want to pay to have this done at the local that I bought it from. It also seems a bit less powered that my old sears/poulan 32cc.


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## 30yearTech (Sep 14, 2006)

The carburetor for all intensive purposes, is not adjustable. If the problem is with the carburetor, then it's likely not just an adjustment. It could be a restricted exhaust port if your problem is low power, old fuel can also cause low power. On something this new, I would not mess with it. A good dealer should take care of any issues under the warranty. If your local dealer will not, I would contact Echo to find a dealer that will take care of it for you.


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## smeltjr (May 8, 2005)

30 YR. Thnx.
Followup. Had it in at the dealer and no questions asked. Took me in the back. FYI there is a safety cap and there is a high speed mixture that is under the primer bulb. Black plastic/rubber thing he pulled out and exposed a small brass screw. Leaned it about 1/8 turn and up to spec at 7450 rpm. He left the cap off but said I can lways bring it back as these rotries are indeed ficlkle but it is a good machine. If it helps anyone down the road.


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## 30yearTech (Sep 14, 2006)

smeltjr said:


> 30 YR. Thnx.
> Followup. Had it in at the dealer and no questions asked. Took me in the back. FYI there is a safety cap and there is a high speed mixture that is under the primer bulb. Black plastic/rubber thing he pulled out and exposed a small brass screw. Leaned it about 1/8 turn and up to spec at 7450 rpm. He left the cap off but said I can lways bring it back as these rotries are indeed ficlkle but it is a good machine. If it helps anyone down the road.


I know about the cap, it's actually a violation of E.P.A. rules for anyone to tamper with the settings, other then an authorized dealer. It's a violation to leave the cap off as well. Newer oxygenated fuels can affect mixture settings, make sure to use at least an 89 octane fuel.


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