Humming Sound When Trying to Start

[West T]

I have been a member on Ferguson forum here on YTC but have never inquired about my lawnmower. Fortunately because I haven't had any real issues with it. However, yesterday when I went to start my JD Z425 (w/ the Briggs Engine) it gave off a humming sound around the engine. I just had it out the day before with no problems (and all Spring for that matter). I tried jumping it with the truck but the same humming noise occurred. I put a battery charger on it and the battery showed to be fully charged. I checked all the safety controls and the brake was on, blades were off, and the steering controls were in the start position. Any help you guys can offer is much appreciated. Thanks in advance.

Shawn

 

[MrJDMan80]

if it only does it when you are trying to crank then it is most likely your valves out of adjustment. This seems to be something that happens "all of the sudden". Try turning the engine by hand just over compression. Then turn the key to start again. It should crank and take off.
The valves should be adjusted to .004" for the automatic compression release to work proper.
Tim

 

[rustyj14]

Maybe a herd of honey bees has built a nest in the tractor, and you are disturbing them! RJ

 

[IH2444]

Starter solenoid?

 

[El Toro]

I would second the solenoid. Take off the ground cable and clean all connections using 320 wet or dry or 400 until they're shiny including at the solenoid. Also feel the starter motor while a helper makes an attempt to start the engine. The starter may be defective. The bendix drive may not be engaging the ring gear on the flywheel. Hal

 

[T.R.K.]

Did you try manually rolling the engine over? It may have gasoline in the cylinder and the starter can't turn it.

 

[West T]

Thanks guys. I did not roll the engine yet. I did take the battery into have it checked and it was at 12.3V (60%) which should be sufficient. But I went ahead and put it on the charger for a couple hours last night. I called my JD dealer and he suggested the starter solonoid as well. My wife is picking it up for me today so hopefully I'll be up and running tonight. If not I'll see about rolling the engine.

 

[kj@junction]

have had the starter lock up and that may cause the buzzzing sound, peck on the starter and then try it could be the drive didn't release. kj

 

[JD Seller]

I have had the starter stick in the flywheel and not crank the engine over on Briggs engines. They depend on the little bit of head start the starter drive gives the starter. So just rock the engine back and forth just a little bit. That will usually let the starter drive pop back out of the flywheel. Then they will usually crank right up.

 

[BAnNC]

Had similar issues to what JD Seller described. Starter gear would contact flywheel and stick. Most of the teeth on the gear were worn off. Less than $6 fix. Cranks every time now.

 

[West T]

Well, just to update you guys for anyone else who may experience something similar...as I stated previously, battery checked good so I pick up a starter selonoid and installed it. Same humming noise. So that didn't fix my problem. I began peeling off the plastic engine clanning and inspecting the starter. Something looked a little peculiar as there was no gear on the bendix drive to engage the fly wheel. Started looking around and found it. See the attached pic. The humming sound was the starter spinning like it was supposed to but there was nothing to mate up with the flywheel. $3.50 at O'Rielly's and she started up like a charm. Thanks for your help.