avu3

I have been searching and reading threads for the past hour about what to do with our 1985 FB Pro-7.

We've got a Yaw carb and the rats nest removed.

Our charcoal cannister and PCV are in a state of flux.

As I recall, the charcoal cannister was only hooked to the two lines near on the firewall, one larger, one small diameter. They appear to go only to the Fuel tank.

Was one of those acutally a vaccum line? Where is the other end of it? The only vaccum line we have on the carb now is to the distributor. Should it have vaccum applied to one of the lines from the Carb? Which one if so?

Second, the PCV, we have it capped right now (car not being run) but want to hook it back up. Should it be hooked up through the vaccum valve as recommended in the rats nest removal instructions, or should it just be vented to the atmosphere? I see people seeming to recommend both. In other cars, I have vented it to the atmosphere successfully (V8's) So I am familar, but not on the rotory.

Thanks, May you always go fast.

Scott Miller
miller-motorsports.com

rhinor61

I take it at you are building a Pro7 car, right?

Yaw build my carburetor for me back in 1999, which I won the NASA SF PRO7b class. It was PRO7 cars running against PS-2 Rx-7, took 5th in that. Make sure you only use your fuel pressure gage for set up and TS, do not leave it on the car.

What Jets did Paul put in your Carburetor? Keep Hagg away from it, out of respect of Yaws secrets.

So why are you worried about the Charcoal canister? Its part of the emmissions crap, which you get to remove, so put the fat hose into your catch can to vent. I used a old coolant over flow bottle, it important that is hose stay at the top of the bottle to vent.

PVC on a 12a, where is that? You mean the purge valve?
I never ran it with out any problem, but you will get the milky moisture in the oil fill tube, so it would be a good idea to hook it in.

John

avu3

Thanks John,

Yes we are building a Pro-7 to run in NorCal. Yes we are sensitive to the Yaw carb. Yes we have removed the pressure gauge.

Thanks for the info on the tank vent and purge issue.

Scott

Wankelguy

Here's what I did on my '80:
I capped off the PCV valve on the manifold, and ran a hose from one of the nipples on the oil filler tube to my carbon canister (in the aircleaner lid on SA models), then teed the tank purge line into that line. I also installed a little oil breather filter (a fuel filter will work also) on the other nipple on the oil filler tube.
Works great, no fumes and no oil/water emulsion in the oil filler tube. Also, no vacuum loss as the tube goes to the intake of the carb.

Captain Lou

does the RX have a PCV valve?

i went looking in a manual for it , in an effort to determine one of teh causes of my crap performance and it appeared like the rotary doesn't actually have one.


and i then tried to buy one and they hadn't heard of one either...

Rx7carl

AFAIK, only a 79 has a PCV (its on the intake manifold) Later models use a vacum purge valve as detailed in the emissions removal tutorial.