Outdoor Power Equipment and Small Engines - Briggs wont start(*&&^((*&

Ok, I have a Briggs Mdl # 12F802 Type 2409-E1. This for all practical purposes in a near new engine even though it was purchased several years ago. It has been setting unused until about a month ago when my old high wheel mowers engine finally gave up the ghost (only about 55 or 60 yrs old) Ok got the newer one out and changed oil, air filter, spark plug, new gas, the works. Pushed the primer bulb and it started second pull. Ran it about a week, no problem, first or second pull start.
Trouble started when I decided to put the newr engine on the old frame because (A) the newer one is a rear discharge and I dont have a catcher for it, (B) the high wheels blade is on a deck out front with the engine on the rear so I can get under fencelines etc. Changed it over and havent been able to get it to start since. Has fire to plug, Gasoline is clean and flowing good but the only thing I can get it to do is once in awhile it will POP back though the Carbureter like it was out of time. Have checked flywheel key and mag and cant see anything wrong. Any suggestions are greatly appreciated and most certainly welcome. :confused: :confused:

This new engine is designed with a light weight aluminum flywheel.

The blade being mounted to the bottom of the crankshaft (on other mower) acts as a counter weight to help with momentum of the engine rolling past compression stroke while cranking.

Removing the blade and installing a pulley to the end of the crankshaft drops the needed momentum for the engine to roll past compression stroke properly.

In a nutshell, This engine will not run on your old mower.

But, I remember seeing a round plate (counter weight) mounted to the crankshaft along with a pulley but can't recall which brand mower used it.


Good Luck

Yeah, I thought of that also. Sorry forgot to mention in first post that I made a flywheel to take the place of the blade, weighs about 5lb. It is however only about 7" diameter, Possibly needs larger diameter?

Since my last post I remembered where I'd seen this blamed thing....

We have a Sarlo Hi-wheel mower in our rental fleet with this "flywheel".

Reference # 105

http://i107.photobucket.com/albums/m314/Restrorob/Misc/SarloWBEngineMount.jpg

It's Sarlo part #1208

I could get all the measurements off our's if you like ?

If you could do that it would be greatly appreciated. I looked again and the one I made is only about 2 1/2 lb and about 5" in diameter. Kinda had the big eye on it I guess. Anyway its too small I think. Thanks

Will get them together tomorrow when I return to the shop.... :thumbup:

OK, Here's what I got;

Diameter is 7"

Thickness is 0.273" or roughly 9/16"

The center hole diameter is 3/8", The same size as the crank bolt. The plate fits flat on the end of the crank.

I would have removed the plate and weighted it but the frame was right under the bolt, I would have had to loosen the engine and slide it forward to gain access then re-adjust everything afterward.

Good Luck

Thats ok. You did good. I have something similar that should work, the only thing is that it has about a 3/4" hole in it. I'll have to make me a bushing but it should work. Just have to make sure everything is balanced and straight. Thank you very much for taking the time to get those measurements for me. I do appreciate it, just hope I can return the favor sometime.

Beer 4U2 :beers:

No problem...... ;)


If all else fails you could order the plate from Sarlo.....


Good Luck

Just thought you might like to know that putting a flywheel on the pulley was what was needed. Runs great. Many Many THANKS.

Super !

Thanks for the update..... ;)


Cya