Jaime Enriquez

I bought a 12A motor con Nikki, but it came out of an Rx2. Not sure if it's an old pre-83 Nikki or post-83. How can I determine? (de-smogged and nested)

It needs an accelerator pump diaphram and I'm not sure what to get. Are they all the same? If I get the acc. diaphram from Mazdatrix or the dealer, will it work?

Thanks....Jaime

waysrx7

The air vent solenoid was changed in the '84-'85 carbs. You can check that if it still has it, and I'm pretty sure you can still tell a difference even if it doesn't.
http://www.wankel.net/~krwright/file...01979-1985.pdf

Jeff20B

iTrader: (13)

Can you post a picture? By the way there is a difference in accel pumps from early to late carbs (like early '70s to late '70s I think). Kudos for asking on the forum.

trochoid

iTrader: (6)

I thought the pre-79s came with the Hitachi, or was that 13Bs only?

j9fd3s

iTrader: (3)

the 80 and older carbs have the idle air and mixture screws, thats a tipoff.

81-85 i'm not sure makes a difference?

Jeff20B

iTrader: (13)

Scott, 13B only.

Mike, all I know that's different on the '84-'85 are the extra nipples on top of the air horn near the altitude compensator.

Keeble

iTrader: (3)

so pretty much the carb off my 83 will be plug and play with my 81

Jeff20B

iTrader: (13)

Probably. The rebuild kits state '81-'82, '83 by itself, '84-'85. Go for it.

Jaime Enriquez

Sorry it took so long...here are the pix of the carby.

...also not sure what the numbers mean on the side....jet sizes maybe....not too familiar with the Nikki carb ( only IDA's) This is supposedly a pretty massaged Nikki, but it just doesn't have much squirt. I'm thinking the leaking acc. pump is the main culprit.

Jeff20B

iTrader: (13)

That looks like a '74-'75 Nikki. The numbers are probably jet sizes in SAE. Stock Nikki jets are metric.

Jaime Enriquez

So where should I get an Accelerator pump diaphram...local parts place? Mazdatrix doesn't seem to list 'em.

Also...I'm assuing the large screw is the idle mixture (starting at the base 3 full turns out). What should the setting be on the lower screw? and what exactly does it control?

btw..thanks Jeff.

Jaime Enriquez

Will all 12A accelerator pump diaphrams work on all Nikki's? Can't find early versions listed anywhere on the net.