ok so i got a new exhust header.. and I don't have a cat anymore.. its stright pipe..... when the car is rev up two about 3k .. the pipe turns red hot.. why would this be?

 

damn that happened on my suzuki it burned off the clutch cable!!

 

its nothign to worry about.

 

Since you dont have a cat to clog.you might be running to rich, what s your fuel set up

 

I I have the stock carb on it and ist mechanical.. I think its running rich.. casue it likes to flood and i have shitty gas milage

 

Reset the carb to factory specs and start off from there.
Check the timing and make sure its correct as well. If I recall correctly, off timing on trailing plugs can cause unburned fuel to detonate into the exhaust cycle..That can get hot as hell if your running rich.

 

ok... where would i find factory setting.. and how would i change thats stuff.. i don't know this stuff

 

Do you have a factory manual (blue bible) for your model year? If not, get one from Mazdatrix or other rotary specialist. Before you mess around with your carb, pull your plugs and check them out..Are they wet after you run the car? Are they black and fouled? Plug condition can tell you an awful lot.You may be flooding, have some fuel line blockage on the return, etc..
To adjust the carb I believe the following is standard on a stock Nikki, although there may be some differences depending on the year:
Turn the adjustment screw clockwise until it seats, then back it out 2 1/2 x. Continue backing out screw in small increments until the idle gets rough then back in just enough to smooth it out. After that make sure the idle speed screw located close to the linkage points is adjusted until you get 750-800 rpm or so.
As far as the timing, you should read up on it or get some one else to do it. You will need a timing light. The bible is pretty good at explaining how to check and adjust timing. I would say that if the car ran ok before and current symptom was post exhaust change that carb settings might need to be adjusted first and your timing is prob safe.

 

the spark plugs are black.. moslty cause my car flooded alot during the winter cause of the could. they only have about 4k km on them so I thinks thats a problem there... the also never really ran great u would need to put the accel pedel town far for the car to move... i think i'm just going to take it the the calgary rx-7 specialties, buy my house and them look at it

 

Good idea. I used to have an 81 with a street ported 13B with RB header/exhaust and a Mikuni carb..My header would get a little red after running the car pretty hard. In my opinion it was normal. In your case it happens at 3k rpm which to me sounds a little weird.

 

or.......you can always just leave it be, and have this happen:

 

Is that a melted cat?

I've never ssen one actually melt...

 

melted....exploded....its all the same to me.....

 

Ya i saw that when u show everyone it.. thats shitty