Shop Products
Houzz Logo Print
fsrph

RPM's drop over leaves

fsrph
12 years ago

With the nice weather in Pa recentely I decided to change the oil and see how the lawnmower survived the winter. It is a fairly new Toro SR about 1 and 1/2 years old. It was stored without gas and I put in some fresh gas today. Sprayed some carb cleaner and t started up after about 8 pills. I let it run for about 20 minutes and it sounded fine.

Then I thought I'd just test it cutting and it sounded OK. But then, I went over some leaves and the rpm's immediately dropped. The engine didn't stop just rpm's dropped a lot. Past the leaves the rpm's went back up to normal. Next bit of leaves I hit same thing, rpm's dropped. Any idea what the problem is? Thanks.

Francis

Comments (6)

  • rustyj14
    12 years ago

    It doesn't like you feeding it leaves, so stop it! Sheesh!
    Also--the leaves are probably thick and wet, under the top layer, unless you stored them inside yer cellar. They are bunching up under the deck because the blade can't spin fast enough to chop them up. You bought a grass cutter, not a leaf chopper!

  • tomplum
    12 years ago

    If it is running strong enough, you probably have no worries. Here's the thing about running these out of fuel. You never do as there is always a remainder in the carb bowl. The bowl is vented, though internally, and the fuel turns to a point that it is difficult for the engine to run on. Use a fuel treatment that can deal w/ alcohol symptoms and stabilize the fuel for best results.

  • fsrph
    Original Author
    12 years ago

    Just a few things. The leaves were not thick or wet. I just raked some from near the house foundation and ran the mower over them. When the mower was operating properly it would not be any problem at all running over leaves. I have cut leaves much worse than this many times and the mower didn't even blink.

    The carb issues, if that is what it is worng, is a persistant problem with this Toro. Right out of the box, when started the mower would hunt (the dealers words) thru different rpm's till it stabalized the rpm's. So, this mower is 1 and 1/2 years old and the dealer has already the carb twice. I suspect this may be #3. I follow the rules of using frest gas and not letting the gas sit in the mower all winter. Is there gas additives andone could recommend? I have tried Marvel Mystery additive and carb cleaner in the gas with not great results. Thanks.
    Francis

  • bill_kapaun
    12 years ago

    For my first tank of gas in the SPRING, I add a STRONG dose of carb cleaner just prior to mowing.
    After mowing, I'll top off the tank to dilute the remaining "dose" and run it a few minutes so I don't have a "strong dose" sitting in the fuel lines etc.

  • tomplum
    12 years ago

    Maybe you can give us some model numbers. Sure, it is possible to have a defective carb. Early on. If there are repetitive carb issues, the logical explanation- leads back to the fuel source. The wild card here is if there was debris in the tank, was the entire fuel system cleaned. Is the supply can clean, kept sealed, fuel used while fresh etc. Additives are available that stabilize fuel and deal with symptoms brought on by alcohol. Startron, Marine Stabile, CRC has one etc. Gas sitting in the mower, if it is treated when the fuel is fresh is fine. It would be good if bill might qualify what a strong dose is.
    Going back to your issues today, if it sounds fine to you, it is probably fine. I can't really say that leaves would be a good judge of power here myself. Plus, you really didn't say if the dealer cleaned the carb 2ce or replaced it.

  • 1saxman
    12 years ago

    Your engine is not producing adequate power if it bogs down over a few leaves. most likely this is caused by a very lean mixture due to an air leak in the intake tract or fouling in the carburetor. I think the recent SR4s have B&S engines. It it was a Tecumseh I could tell you what to do but i haven't owned a B&S since the one I bought in 1989 that is still in use.