Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

Mower starts and then dies

N Dennison's Avatar

Join Date: Jun 2001
Posts: 86

06-19-02, 10:11 AM   #1  
Mower starts and then dies

I think I've messed up my lawn mower, Briggs & Stratton 3.75. It has been running fine...just tuned up this year at local shop. Today, it is starting, but then rpms rise and fall a couple of times and it dies. It will start every time that it is primed. I took the carb cover off and it did the same thing, so I don't think it is an air filter problem.

So, here's the bad thing: I've been turning it onto its side to get the wet grass out of it. Any chance that did something?

Also, any idea why my air filter feels gummy? Almost like syrup got into it? (It would be on the top when I tilt it.)


Sponsored Links
BSB's Avatar

Join Date: Mar 2001
Posts: 782

06-19-02, 06:33 PM   #2  
turning on its side should not do any damage, might flood, but letting it sit untill the next mowing should take care of that. (time clears most flooding) Is the choke stuck? are all the springs still in place?

Not sure about the gummy feel to the air filter, but after a few dusty mows I will rinse out my filter in gas, dry and work a few drops of oil into the foam to help catch more crap.

It ran fine after the tune up? and didn't seem to show any signs of break down the last time used?


cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567

06-19-02, 09:31 PM   #3  
Hello N Dennison!

Turning it on it's side for short amounts of time shouldn't hurt anything.
Clean the air filter and re-oil, make sure there is no water in the tank. If problem still persists, remove the carb from the tank and replace the diaphragm between the carb and the tank.

"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

N Dennison's Avatar

Join Date: Jun 2001
Posts: 86

06-20-02, 09:39 AM   #4  

Maybe the tune-up guy did put some oil on the filter...I believe you could describe the feel that way.

Good to hear turning it over didn't do it.

No, it was fine the previous mow.

I don't have the book since the mower was a gift. Is it hard to remove the diaphragm? I'm not all thumbs, but I don't want to make matters worse.

Sharp Advice's Avatar
Admin, Forums Host & Manager

Join Date: Feb 1998
Posts: 10,440

06-20-02, 08:00 PM   #5  
Hello: N Dennison

The information you have gotten thus far is accurate. A gummed up carb is the most likely cause of the problem your describing.

A gummed up carb can be caused by any substance other then pure gas and air. An overly wet oil soaked air filter can cause the problem, as indicated.

Another rare possibility can be a restricted air vent in the fuel cap. Try running the engine without the cap installed for a short time and note if there is any changes.

If the engine still exhibits the same problem, it's not the gas tanks cap. If it doesn't, the caps vent hole is plugged and or restricted. If this is the case, replace the cap or clear the air intake under the rubber or cork seal.

Not being all thumbs is a handy ability to have. If you take the carb off to clean it or have taken it off already, be sure to note what goes where and reinstall and connect everything exactly as it was and all should be fine.

Regards and Good Luck, Small Engine Forum Host & Moderator
Tom_Bart.....TCB4U2B2B.....Company Enterprises.
Fast...Fair...Friendly & Highly Efficient Services....
"Accurate Power Equipment Company"
Small Engine Diagnostics Services and Repair.

Note to Brian...BSB
Long time since I heard from you Brian.
Thanks for your assistance on this topic too.

Search this Thread