Siraniko

iTrader: (13)

i recently installed a 12-A 6port engine with original carb etc etc. however, cant get the idle down, i adjusted every little adjustment screw i found but no luck. im not familiar with this setting at all. while the air cleaner assembly is on, i sprayed carb cleaner on all vaccum lines to temporary seal any leak and even disconnected the gas cable but nothing happened.

i have no problem disconnecting everything else and just install a modified rx-2 carb but this is is challenge and dont feel giving up.

anyone????

stinkfist

Where did you get a 6 port 12a? As far as I know there where only very few made and only in japan.

Anyway, there is a screw under your throttle linkage kinda hidden in all that mess. you can use this to adjust how much the butterflies stay open at idle. Your throttle cable itself can also be adjusted too tight and hold the throttle linkage open. try backing off the bolt on top where the cable hooks to the carb.

Good luck,
Mike

Siraniko

iTrader: (13)

i was holding it for a friend but ended up getting a 83 gs for project. this is my first time to work on a 12-A 6port and i really thought it comes with a turbo but it didnt. anyways, i will try that and i will keep you posted.

thanks again.

Siraniko

iTrader: (13)

sorry....not sure where my friend bought it but ur right, its a japanese version.

SilverRocket

I wonder if your secondaries are stuck open a little?

Also, if you have a vacuum problem, the adjustment screws likely will not work properly... spraying carb cleaner may help you detect a leak, but I don't see how that would eliminate it.

I think you should double-check all vacuum connections to make sure you have it hooked up right.

Siraniko

iTrader: (13)

good point.

speckamp

dude! a 12A 6port? wow. Take some pics of that thing! That's pretty cool.

I'd check for a vac leak first. Are all the maifold bolts torqued down good? Vac lines? How'd you hook up the 6port actuators? on the 13B-6pi there's a tube that transmits backpressure from the cat to the diaphragms that open the ports, did you have something like that come with the engine, or are they opened with the secondaries on the carb?

--matt

Siraniko

iTrader: (13)

i have no problem switching to an after market carb but since i never seen or work on this engine before, i decided to keep it original as much as possible.

Heres a brief description:
It came in tact with the orig exhaust manifold, intake, carb etc. therefore, it was an easy slap on job except had to modify the gas cable bracket since it originated as a right hand drive.

Engine mounts were on the side just like the second gens, but the front engine cover has mounts.

the carb is almost the same except it has coolant hoses on both sides of the carb cover.

i dont think the 6port actuators are vacuum operated.

i will work on it tomorrow night.

thank you.

Siraniko

iTrader: (13)

found the problem....the butterfly inside the intake manifold (cant remember the name) was stuck open. dont know what caused it but it seemed that someone hit with a hammer as it will not even turn by hand. had to cut it our with a sawsall and pull the rod out with a vice grip. replaced it with another one from a regular 12-a manifold. runs good with no problem.

this weekend, i will replaced it with a ported rx2 carb to ck the difference in performance.

thanks eveyone

nick812

OK I spent hours looking at serveral different treads this was the oldest. I was thinking about building a 6 port 12A and was wanting to hear if it was worth tring? But from what i have read i think i am either gonna stick with the 4 port 12A or go with the 4 port 13B. I wanna thank every1 that posted in all these treads very helpful.

Naegleria_Fowleri

Honestly you can gain a lot more power through porting four port engines than you can six ports, but stock for stock the six ports will produce more power. If you are going to be porting the engine out I say stick with four ports. You can get them bigger, and thus create more power.

I am interested in knowing the results of using the upgraded carb on this engine though. I hadn't heard of a six port 12a until reading this ancient thread.

84stock

iTrader: (5)

I think you can beat a functioning 6 port engine for a streetable n/a set up. Leave the 4 ports near stock and bridge the aux ports along with pineapple sleeves and a small nitrous shot and you've got a hell of a set up.

nick812

Ok i was hoping to get more of the people that had used a 6 port 12A to say something? Where are all of you? I know some of them are kinda old. I mean that in a good way guy's your knowlage is what us younger people wanna be when we get older. So come on guy's chime in on this. I never did in all my searches find anyone finsh th 6 port story how it drives and stuff.

slashdawg00110

Shutter valve aka coasting valve, assuming it's like the 81-85 manifolds. I'm not sure the fact that it was open and wouldn't close would cause the problem you described. Maybe the shaft was bent and causing a vacuum leak. You did say someone hit it with a hammer ...