Suspect my vacuum motor is shot (only a few years old). It doesn't really react to the engine rpm/vacuum much.

Should I be able to pull it closed with my lung power and hold it?

I can just get it to move a little, but it doesn't hold......

Oh well, guess these repops only last a few years.

Joe

 

The repop motors are junk.


I sold 2 on e-Bay, originals, and they still work great after 40+ years.

 

Are you testing this by just revving the engine in neutral? It could very well be that the engine vacuum never drops low enough to open the door. You need a load on the engine.

Any normal amount of engine vacuum (let's say more than 7 inches) should be enough to close the door. Does yours close?

Shutting off the engine (and thus reducing vacuum to zero) should open the door. Does yours open?

 

I noticed that is was not closing at all. It was moving slightly up and down.

When it was working properly, it would open and close when I blip the throttle at the carb.

I removed it and when I try to pull it closed with lung power, the bar pulls in some then extends right back out. It won't hold.

I actually think it's affecting my cold starts. I was planning to rest my timing/choke and now I'm going to wait to see if this clears it up?

Thanks.

 

Disconnect the vacuum hose at the OAI motor. Push in the plunger. Does it move freely? If not, determine if the resistance is inside the motor or the flapper door itself.

Once you've pushed in the plunger, press your finger over the nipple, sealing it. Now release the plunger. Does it stay plunged? If it extends while your finger seals the nipple, there's a leak inside the vacuum motor -- it's toast.

You can use this same method to check the vacuum brake (aka choke pull-off) on your carb.

 

Yeah, I've already confirmed the diaphragm is done. Ordered another repop.

I guess if it lasts another six years I'll be fine.

Now I just have to work the stupid push-on barbed retainer off the rivet without breaking plastic.

Because that would not be cool......

 

Mine lasted about two thousand miles. Re pop junk. Once broken it creates a vacuum leak so you have to unhook it and plug the hose till you replace it.