Hello all,

I'm finishing up my first engine rebuild. The trouble is, I needed to source a used carb spacer to replace mine, which was destroyed (my dad and I destroyed while trying to "remove" the gasket on the carb, we know better now).

The carb spacer I received in the mail is the right part number for an S1 RX-7, but the sealing surface in the top and bottom of the carb spacer is imperfect; it isn't perfectly flat and naturally shows some signs of being used before.

My dad thinks I should take the carb off the car and install carb gaskets from a carb rebuild kit on both sides of the spacer, but I've read on here that people use only the carb spacer without gaskets, and I'm not sure that the gaskets from the carb rebuild kit should be used, because they have no holes for the carb vacuum ports. What should I do?

 

If I can get measurements I can create you a model and then you can outsource print or cnc it. I know that's likely your last resort but it shouldn't take me but a moment to draw.

If you want to go this route just post a picture of the spacer with some measurements and we can go from there.

 

Thanks for the offer! I really appreciate it. I just put the carb on with just the spacer and no gaskets. My idle is high and rough, but the car runs and drives. I suspect a vacuum leak. I'll hunt through the harness tonight and tomorrow, and I'll message you if it turns out that I need to take you up on the offer! Thanks again.

 

They all look like they have issues but will actually work fine. Do not try to "fix" it again. Do not use the extra gaskets either.

Sounds like you are on your way. Vacuum leaks cause all kinds of issues. Spray some carb cleaner around the connections on the carb and see if the idle changes when you hit the leak.

 

Good to know that all the spacers look worn. I definitely won't make the mistake of trying to "fix" the spacer again! It was a terrible headache to try to find the S1 spacer I actually think that timing may be the issue, not a vacuum leak. I'll definitely check for vacuum leaks anyway, though. The timing marks on my pulley are really hard to see. Do you have any advice for timing these engines? I can find the first set of marks, but not the second set.

 

I marked the pulley with a Sharpie Silver Metalic.

Timing for Leading is done by connecting your timing light to the L1 (Leading #1) spark plug lead, loosing the adjusting nut and turn the distributor so the leading pulley mark aligns with the inidcator.
Timing for the Trailing is done by connceting your timing light to the T1 (Trailing #1) spark plug lead. Adjusting requires moving the trailing vacuum advance in or out from the distributor.

1st image: Note the outer double pulley has been removed.
2nd image: From the 85 FSM - Engine Electrical, downloaded from second sticky thread at the top of the forum. The 85 FSM contains multiple downloads.

 

I checked an early FSM. My reference to L1 and T1 are usually indicated on the distributor cap.
Just for clarification, timing is set on the front rotor (#1). The leading spark plugs are the lower ones and the upper ones are the trailing.

 

Thanks so much for the help, everyone! I solved the timing issue by rotating the distributor shaft, not the cap, until I could use the distributor cap only to move the timing mark to the timing needle. My car seems to be running perfectly now! I'll be sure to break in my new engine carefully.

 

That's great you got it sorted out! Enjoy