# Toro trimmer won't rev after warm up



## Len9095 (Jul 18, 2008)

I am baffled by a Toro trimmer (25cc) inherited from my dad. It has a history (with me) of not revving after it gets warmed up. I have rebuilt the carb twice, replaced all gaskets, checked the plug, everything I can think of. After a normal start sequence, the machine will work fine, revving on command for about 5 minutes. Then, when you throttle up, it drops RPMs slightly and continues to run. If left alone for several hours or overnight, it will start as usual and repeat the failure.

The first carb overhaul (done by a shop) seemed to work for a while, but the problem came back. The second overhaul (done by me) didn't fix the problem. (I noticed two extra gaskets in the rebuild kit after replacing all, one-for-one.)

It seems to me that some diaphragm or temp sensitive part in the carburetor is dumping fuel or vacuum, or perhaps a needle valve is not seating or opening, but I'm clueless where to look next.

HELP !!!!

Len


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## 30yearTech (Sep 14, 2006)

You may have an air leak somewhere around the engine or a seal that leaks when the engine heats up a little. You can spray some carburetor or brake cleaner around the areas where the cylinder and crankcase meet or anyplace that has a gasket or a seal, do this while the engine is running and listen for changes in rpm or stalling. If you find a place that the spray affects, this is where there is an air leak into the engine.

Best of Luck...


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## PCC (May 1, 2008)

I had a similar sounding problem with an Echo SRM-2400 weedeater, I'm not 100% sure I've got it fixed now, but I haven't gotten it to falter the last three times I've used it. I think what did it for me was a cleaning of the gas tank check valve/vent. When it fails, have you tried loosening the gas tank cap to see if a little air remedies the problem?

Any thoughts 30yr?

Patrick


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## 30yearTech (Sep 14, 2006)

That could be another source for the problem as well. 

Len, do you have your model and S/N of your trimmer??


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