Briggs L Twin Hard To Start

11 years ago

Hello everyone,

I hate to start a thread about this, but I'd like to give my story of what's going on.

My Grandma has an old Montgomery Ward with an 18HP Briggs L twin that is hard to start. It is like an OHV engine that needs valve lash adjusted. It has gotten harder and harder to start, and even with a fresh battery you have to jump it off a car to get it to start. About two years ago she took it to get the starter replaced. I've never heard of who she took it to. When we got it back, it wouldnt start at all. She took it back and he did something else to it and it was back to square one it will barely crank on its own, and you still had to jump it. I'm not so sure he even replaced it.

So far, I have replaced the battery, solenoid, battery cables from the battery, to the solenoid, and to the starter with 2 gauge. I crimped and soldered all the connections. I cleaned and replaced all the grounds. That seemed to help a bit, but it still wont start on its own battery.

I also took jumper cables and hooked the positive to the postive post on the starter, and the negative to the motor, and it still barely crankes.

When its started it runs like its brand new.

I dont have the engine number, but I can get it tomorrow.

Any other suggestions? Is it just time to get a new B&S OEM starter?

Thanks in advance

Tyler Lewis

Comments (7)

walt2002
11 years ago
May be carbon build up in heads. Might try some SeaFoam per instructions on the can OR remove heads and scrape carbon out. This is fairly common complaint and you have covered several of the usual causes already.

Walt Conner
rcbe
11 years ago
two ther things: put a new, correct OEM plug in the engine - properly gapped - and make sure the choke butterfly plate/slide is fully closing in the carb throat when you are fixing to make a cold start attempt.
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bluemower
11 years ago
here are some ideas:
1. change the engine oil in case someone filled with the wrong grade. SAE 30 is the correct oil for the L head twin. Make sure this is not overserviced.
2. Check the valve clearance. If there is too much valve clearance, the compression may increase.
3. Have the cylinder heads pulled to remove the carbon.
4. Look over all the battery connections and the engine mounting bolts for security. Sometimes the connections may be tight, but there is still resistance.
5. The starter could be defective. Was this replaced with a used starter or new. Aftermarket or OEM?
dr_mike
11 years ago
does engine just spin slow or does it spin normally? if it is spinning slow, remove the spark plugs and see if this makes a difference.
it could be a bad starter even if it was replaced withing the past few years. you try taking it apart and clean it up. other wise it as the others said, valve clearence and carbon build up.
WV8VFD
Original Author
11 years ago
Gonna try some seafoam tonight if the rain holds off. I'll change the oil. Starter was probably aftermarket, I remember my grandma going on about such a "great" deal she got on it, and the cheapest OEM I have found is 119.

The engine spins slow, if at all when it hits the compression strokes, sometimes even when it is being jumped. I'll remove the plugs tonight and see.

Thanks everyone for the suggestions so far!
rustyj14
11 years ago
I'm a long time member of the local VFD. One evening, we were pumping out several ponds at the local YMCA. The guys were using portable pumps, to draw out the stinky water. one pump workd ok, but the other one just wouldn't start! The man in charge of the pumps couldn't figure out what the trouble was. Finally they looked at me--the "resident" small engine fixer. I got a screw-driver and removed the air filter, and the engine quickly ran much better! I think they never changed those filters, even after many years of use!
WV8VFD
Original Author
11 years ago
I finally got it to start on its own!

I got a can of seafoam, went out there, put some in the oil, some in the gas, a tiny bit in each cylinder through the spark plug holes, cranked it with the plugs out, reinstalled the plugs, fired it up, and slowly put some in through the intake. I ran it till it quit smoking and shut it off. It still would hardly start. So in frustration, and a last ditch effort I put some in each cylinder and reinstalled the plugs. Today I went out to mow, spun the engine by hand some, and put the cowl back on, hooked the battery back up, and it fired right up. It started better than some of my friends mowers. Ran it for about two hours and each time it was shut off, it started right back up. Before, when the motor was warm, it wouldnt even start when jumping it off the car.

I'm going to do an oil change on it this weekend.

I want to thank EVERYONE who replied with suggestions. I really appreciate it.

Thanks a ton!

Tyler Lewis