3 HP Briggs only starts with hand over carb.

[Hemidude]

Good Morning All,
My little old 3hp Craftsman Briggs edger will only start if I cover the carb with my hand for a pull. Even with the choke on. It fires right up on the second or third pull and will stay running with the choke on. And it will stay running with the choke off once the engine has run for a minute or two. I pulled the carb off (Lauson Power Products diaphram type carb) cleaned it out good, gaskets replaced, but not the diaphram. I would have replaced it but I can't find one. Pulled the tank and cleaned out with new fuel line. Still starts the same.
Any suggestions??? I am thinking the diaphram is shot???? No longer flexible as it should be??
THANKS .....

 

[Jack17]

I'm not 100% sure about your particular machine but it almost sounds like you're missing a step in start up sequence. With an older machines (like my Ariens blower for example) there is a spring return plunger (no priming bulb) that, when pushed in, drives a round plate that covers carb air intake completely in similar fashion like you're doing it on your machine with your hand. So, the start up sequence goes like this: ignition key in OFF, choke ON, push plunger IN covering up an air intake and prime engine with 3 strokes of recoil starter, ignition ON, pull (engine fires up)...warm it up and go about your business. Your machine most likely did come with a priming bulb instead of a plunger but you're simply forgetting to prime the engine with the ignition OFF before actual start up. What I'm saying is that there might not be anything wrong with your machine?

 

[Hemidude]

Thanks for the reply.
This is a very basic motor/edger with the old school throttle/cable assembly. Actually there is no cable on this one, the throttle lever is actually mounted on the engine, near the carb. Also no on/off switch or primer mechanism... I got this edger from my dad years ago and it started fine with just the choke on, with a couple pulls of the starter rope. Something weny awry with it last year.

 

[Jack17]

Check out this website: http://outdoorpowerinfo.com/repairs/tecumseh_carb_632334a.asp
Some good info about carbs with really good photos.

 

[Grassbandit]

Check out this website: http://outdoorpowerinfo.com/repairs/tecumseh_carb_632334a.asp
Some good info about carbs with really good photos.

Thanks for sharing, this is indeed a good resource.

 

[Rivets]

I'm confused, I've never seen a Briggs engine with a Lausen carb. Please post engine model numbers. This manual might help you.

http://evanosaurus.com/ebooks/270962 Single Cylinder L-Head BRIGGS & STRATTON.pdf

 

[Hemidude]

Thanks everyone..:thumbsup: I will get and post the engine model numbers this weekend. Try and take a pic too...

 

[silver1]

I'm confused, I've never seen a Briggs engine with a Lausen carb. Please post engine model numbers. This manual might help you.

http://evanosaurus.com/ebooks/270962 Single Cylinder L-Head BRIGGS & STRATTON.pdf

If you go to page 43 (section 3 pg5), your carb. should be "C" for a 3HP with fuel pump (diaphram). "D" is for 2 HP(no diaphram).

 

[Rivets]

I do know my carbs, but never one of the carbs is a Lausen carb, which is what the OP says he has. That is why I am confused. Should be able to sort it out when he posts numbers and pics.

 

[Hemidude]

I'm confused, I've never seen a Briggs engine with a Lausen carb. Please post engine model numbers. This manual might help you.

http://evanosaurus.com/ebooks/270962 Single Cylinder L-Head BRIGGS & STRATTON.pdf

Well Rivets you were right to be confused.. I found the engine model number (143-711022), googled it, turns out it is a Tecumseh!!!!!! And I found several parts outlets now that I know what the hell I got!!!!
I feel like I have a carb issue. Maybe the diaphragm is shot???? I took the carb off and cleaned it good and it made no difference. Thoughts anyone???
THANKS!!!