DavidMyers53

'83 12A Nikki carburetor (rebuilt a few weeks ago) completely stock.

Car had been sitting for 13 years. Had it running fine, and then filled up the gas tank. It started to have problems cutting off after 2-3 miles. After sitting for 5 minutes it would crank and run a few more miles. While working on the gunk in the gas tank problem, the carb flooded. I did the de-flooding procedure and when I tried to crank it, it immediately flooded again.

I checked the air vent solenoid (as per Haynes manual) and it is not working. I made sure I had power at the connector where it plugs in. I took the solenoid out, grounded it and applied power directly from the battery and it didn't do anything. Two different Mazda dealers say this part is no longer available. Is there an aftermarket source for it, or another work-around? Should I be looking for anouther source for the flooding problem, such as the return hose having gunk in it?

Thanks for any help!

By the way, as a newbie to rotaries, I have found this forum extremely helpful, and members very forgiving for my dumb questions.

Scott1982

I am sure others will reply but I had a flooding problem after rebuilding my carb. I found that the tank was not being vented, so after carefully blowing through the return lines with very low air pressure, (don't want to break anything) I took that gas cap off and the flooding problem went away.

The real problem was then tracked to the charcoal canister that is attached to the vent to the tank - it is an incredibly small hole that was plugged. I drilled it out and all is fine.


You should be able to get the vent solenoid on ebay or here (used section). Others more experienced will comment on whether it is required or not but I run stock so would always want it to present.

Scott

DavidMyers53

Where is the hole in the charcoal cannister located?

Thanks.

Scott1982

Pull off the two hoses, you will see one has a VERY small orifice....

Scott

Kentetsu

Check the level of fuel in your float bowls too. If one or both are empty, then the needle valve(s) are stuck open.

Rogue_Wulff

The smaller hose nipple has the orifice. This hose comes directly from the fuel tank, and is the only vent for the tank.
The canister is located under the hood, on the backside of the strut tower, right hand side.
I also had the same issue with the orifice plugged, and drilled it out. Problem solved.

DavidMyers53

I was reading one of Sterling's post on how to remove the air (float bowl) vent solenoid:


"I also see that you still have the "Float Bowl Vent Solenoid" ...(why couldn't they just call it the damn "vent plunger"!?) hooked up. Make sure you source that back up to the 12V+ black & white lead that goes to it.
This thing is such a damn trouble maker!
You can remove the carb top, and then the solenoid, and you'll see the little plunger inside. The plunger is a white plastic cylinder riveted in there with the solenoid pin that gets spring loaded into the electromagnetic solenoid.
Remove the floats and needles, and hold the carb top in your hand with the plunger perfectly lined up, sitting perched dead center, and smack that bastard with a hammer!
The twenty year old plastic cylinder will break apart, sometimes downright shattering, and then you can release all the pieces.
Simply screw the solenoid, or some other suitably threaded short bolt, along with an aluminum crush washer."


I didn't want to go to the trouble to remove the carburetor top, and since the solenoid pin goes into the plunger when activated, I experimented with a small piece of plastic to see how long something would need to be to make the plunger think the solenoid pin was always activated, thereby always venting the bowl. What I found is that it only takes a piece about the size of a BB, so I scrounged around and found a box of copper coated BB's and stuck one in the plunger and screwed the solenoid back on, of course, leaving the 12 V+ disconnected. It seems to work. Anyone see a problem with this?

Just for good measure, I also drilled out the small hole in the charcoal cannister.

- David