First, I was wondering what diameter the stock exhaust tubing is on my 84 GS, so that I know what borla muffler to order, is it 2 1/4 inch? Also wondering how much increase in power any of you guys would be comfortable producing on the stock clutch and flywheel, as I was considering switching the nikki to a high performance weber carb and or possibly going forced induction. One last thing, I wanted to get the original carb tuned as it has probably not been touched since 84, and was wondering if I could trust someone who has experience with carburetors but not rotary engines to rebuild the carb for performance gain. Is this a bad idea?

 

The stock clutch,if in good shape,should be able to handle just about any bolt on engine mods you perform.The stock 12A can be pushed to about 150hp with external mods only,but its still only a modest torque producer since its a small engine.Torque and torque application is what busts clutch and drivetrain components.Provided you dont go abusing the clutch and drag racing all the time,it should be fine for the forseeable future,especially with the 225MM unit that later 1st gens had.Forced induction will definately warrant a stronger clutch,as torque production will rise sharply.

The stock Nikki cant really be made to perform much better with just a rebuild and jet juggling.It just cant flow enough air.Rebuilding is simple enough,its like a little 4 barrel American carb,little about it is, "rotary specific".
In the past,reaming out the venturies netted big airflow gains,but at the expense of driveability.More recently Paul Yaw and Sterling have found ways to keep the smooth action of the stock Nikki,while gaining large airflow numbers over stock.My Yaw Nikki was an awesome carb and was easy to work on.Since Yaw is no longer making them,Sterling is your man for that mod.I havent used one personally,since I went EFI/turbo years ago,but from what Ive heard,they are excellent carbs.The Weber,Dell and Holley carbs have their merits and fans,but almost always have some shortfall on a streetcar.My modded Nikki on a stock 12A w/light flywheel,was the most fun Ive ever had on a 150HP streetcar......