I searched, but with no luck on this exact problem. I just rebuilt my carb. on my 85 GS. It ran very poor afterward and smoked a ton. I realized it was burning oil. I checked the connections of the clear plastic tubes and they are both in and the connected is good. What could it be?

 

Probably your oil metering pump is not set up properly, and is pumping too much oil. It's about the only thing related to the carb that could affect oil being burned.

 

Yeah, check the linkage that runs from the carb to the OMP. However, I'm not sure if the OMP is capable of pushing enough oil through the carb to cause a noticable issue.

Check your oil level while you're under the hood...

 

Are you sure it is burning oil? What does the smoke look like? It could be running very rich and the smoke is actually caused by too much fuel. Before the carb rebuild, did it run? If so, did it smoke at all?

Another possibility is that the smoke is caused by burning coolant (bad o-ring in intake manifold or bad/pinched o-ring in engine).

My guess would be the smoke and poor running is caused by fuel. Could be a needle valve sticking (they tend to do that after a rebuild), or the floats may not be adjusted correctly. Does it smoke at all rpm or only at idle/low rpm?

Provide as much detail as you can so we can better tell what is actually going on.

 

If it's antifreeze, oil, or gas, you can usually tell by the smell.

 

It ran before the rebuild, but it wouldn't start without starting fluid and flooded easily. It smoked a little when it first started, but barley any and that was only if it had been sitting for a couple days. I'm positive it was oil, it was coming out the exhaust and the smoke was blueish and it smelled like burning oil. Today I tightened all the OMP connections. I noticed that the hose going into the carb from the sub zero start assist was split and was disconnected. I replaced that with a short hose that I screwed a bolt in to seal it. It ran better after that and no more oil came out the exhaust and it only smoked a little, but still smelled like oil. Now it runs terribly with out the choke on. It also can not reach above 5000rpm with the choke on or off and if I put the pedal to the floor it dies. Thanks Jon

 

Any chance you got the jets switched around during the rebuild?

 

I don't believe so, but taking the airhorn off without removing the whole carb. isn't that hard. Do you have a diagram of which one goes where? Cause I will pull it off make sure there are any I didn't miss cleaning and put them all back according to the diagram. Thanks Jon

 

92 primary and 160 secondary.

Hey, maybe you installed the OMP lines on the carb spacer where vacuum is present? Maybe a lot of oil is getting sucked into the engine.

 

With good eyes and a flashlight (and a mirror for the rear ones) you can check your jets through the jet port covers on the sides, without having to remove the air horn.

The Mazda carb manual fails to number some of the jets on the callout page; it's easy to confuse them. I nearly got one bowl set swapped through the stupid mistake of rotating the carb 180 degress without also rotating the diagram. Caught it just before I sealed up. Hazard of working late.

 

Good idea Jeff. This would definitely be worth checking out...

 

I checked all the wires, tubes and vacuum lines are in the right place, and they appear to be correct. I removed the top air horn made sure everything was in the right hole and not clogged up. Then I tightened all the bolts and screws that hold the carb. together and to the intake. After putting it all back together it started with out the choke with about 1-2 sec. of cranking. It ran fine with out the choke on. I was able to floor and redline it. It still had some smoke, but it didn't smell like oil and nothing was leaving the exhaust tip. I couldn't tell on the color as it was dusk. Also the acceleration if very unresponsive and slow. As well it idles at 2500rpm and back fires when I turn the car off. Any more help would be greatly appreciated