WMC 20-B carb parts question.

Can someone please tell me if there is supposed to be a spring underneath the primer- injector diaphragm of this model carb?

I just acquired from a recently sick friend, a 1997 Mariner 6HP that won't start. Every indicator pretty much points toward the carburetor as it hasn't been started in almost two years. I pulled the carb and discovered it to be full of rust, debris and varnished gas. I just picked up a gasket and diaphragm kit to do a clean and rebuild and while looking at a generic diagram it shows a spring that mine does not have. Also, when I pulled the carb I noticed marks on the four screw heads that led me to believe that I wasn't the first person to remove the primer cover.

This has me thinking one of two things; either this model never had a spring or it did have a spring and at some point in time someone partially disassembled the carb and either lost it or failed to replace it.

Thanks in advance!!

You might want to simply pick up an entire primer kit (unless you are getting the full blown carb kit).

Here's a blow-up of the primer assembly and if not reassembled properly, or if it's shot, it can cause no end of issues - most of them resulting in the motor running like crap if it will stay running at all.



H and I, the little spring (like a ball point pen spring) and the little ball bearing will keep the carb from flooding and they can be "challenging" to get right the first time even if you are careful.

So do take care assembling and if you have issues - crappy idle, lot's of smoke etc after the rebuild, suspect that little spring/ball "first" - odds are the ball popped off the spring...

ps. swearing at it loudly sometimes "scares" it into staying in place upon re-assembly

pps. these are great little motors - fix it up, take minimal care of it and you can easily get 20 or 30 more years out of her.

Yeah, looking at the above diagram it's pretty clear that mine's missing some parts from the primer assembly. I noticed when I pulled the carb it looked like the phillips head screws on the primer top plate had been over tightened which confirmed my suspicion that it had been partially disassembled. According to the diagram I'm missing (h,i) the small check ball and spring assembly and (f) the main primer return spring. The rust flakes that I found I'm surmising came from a steel fuel tank.