New Tecumseh carb, primer doesn't work

Joined
Mar 31, 2010
Messages
6,058
Location
Iowa
Hey all, I have a 4.5hp Tecumseh on a Lawn Boy Silver series. Have been battling the carb for a little while - one of the issues it had was a defective primer. I replaced the primer with a kit from Amazon (which came with a few doo-dads that I'm *pretty sure* my carb didn't have) and it never really worked. So this year I decided I was going to sell either this one or another push mower I have.. Either way it needs fixed, so I bought an $18 carb from Amazon and installed it. Well... The primer doesn't work. Shoot something flammable in there and the engine fires up and runs great.. I got nosey and pulled the clip and bulb off it looks like my old carb - no check valve of any kind.. Is that normal?

Am I missing something or am I just a defective operator??
 
Joined
Jan 24, 2013
Messages
1,133
Location
Upstate NY
I never had any experiences with a non functioning primers on any of my carbs, even when replaced new to avoid cleaning the varnish out of the old one (yeah, I know..).

I would ask how does the bulb act when depressed? No matter how many times pressed or during engine operation, does it ever build pressure (resistance felt) when operated? If it never gets firm and constantly makes a sucking sound, my guess is that there is a leak somewhere in either the primer diaphragm bulb or attached tubing that connects to the fuel supply.

If it were me I'd just spray in starter fluid every time and leave the carb plumbing alone.

I have the ability to make carbs operate poorly by just looking at them.
 
Joined
Nov 23, 2015
Messages
1,962
Location
US
Not to ask a stupid question, but since the primer didn't work on the old carb and on the new carb, are you sure the problem is actually in the carb? Could it be either a split primer bulb or in the tube running from the bulb to the carb?

I say this as someone who's been, well, pretty much knee deep in a couple of 6.5hp Duraforce engines for the past week including having the carbs apart a fair few times. There's not much to these carbs.
 
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