Tecumseh carbs, primer bulb vs. non primer

markus

Well-Known Member
#1
Cleaning up my excess parts and going through carbs right now, lotta junk :laugh:



I had read in a thread awhile back about someone having an issue with a primer bulb style carb when they simply capped the inlet...it made the carb flood out. I thought that was a strange thing to happen but really didnt apply to anything I was working on a the time so I didnt put any thought into it.

Anyway as I am going through these carbs I realized alot of the pretty clean ones I threw in the bin are primer bulb versions...probably because I didn't want to deal with flooding or anything like that and was avoiding them like the plague. Everytime I look at one of these carbs I can't see why it would flood if it was capped, there is still a vent hole to the atmosphere :shrug: But today with them side by side I noticed the difference! The vent hole at the top of the chamber is miniscule compared to a non primer bulb style carb, a piece of dust could clog that thing up!!!


left side primer bulb style, right standard non primer (upper vent is that little hole in the top center of the carb body.....


They both go to the same place in the carb body, when you have the bowl and float off there is a welch plug that is visible, If you ever took one off when doing a good rebuild (the plugs come in the kits BTW) there actually is nothing there except a big void

right side shows carb with the plug taken out:


I even found another one in the pile that has no vent hole or inlet for primer at all....it has a direct line into carb body. I guess the theory would be air drawn in while you are pulling the rope would almost act like an Automatic prime :shrug: that's truly just a guess BTW



so some of the things I was thinking about doing with these primer bulb carbs is this,

Plug the inlet and drill the upper vent hole bigger, if you really wanted an OEM look you could nip the bung off or maybe pull it out and a dab of JB weld or simply a rubber hose plug of the right size.

Another option is to utilize it (this is great for the "spray paint specials" :thumbsup:) simply get some weedeater fuel line and route it down so it exits down below the frame somewhere, All it really is anymore is an overflow line for the bowl so if there is a stuck float issue it should flow out of that line not all over and out of carb eating up your fresh rustoleum restoration! I still would drill the upper hole bigger.

Could even drill a hole in the air cleaner base and stick the hose in there too, I dunno if it would pull air into the bowl like that one carb with the inlet in the bore would, if you felt you needed that, but I guess it could help move some air in the bowl :shrug:

Or just buy a new carb...or better yet a harbour fraught Predator and you wont have to mess with this old junk :surrender:
 
Top