Vashner

How do I lock the shutter valve open (84 12a california stock)?

Short of removing the rats nest and replacing the valve. Looking for a quick fix since the vehicle will be retired in a few months. And my back hurts too much to mess with replacing the valve and messing with that rats nightmare.

I used search first yes. Found the nfo that it needs to be fixed or opened but not how to just lock it open.

Kentetsu

I believe you should be able to just move the linkage into the position you desire, then find a way to wire it in place.

In my case, I pulled the carb and then removed the little screws that hold the "flap" on the shaft (leaving the shaft in place, and DO NOT drop a screw into the intake).

blwfly

iTrader: (4)

i removed the whole thing and jb welded the holes

orion84gsl

iTrader: (5)

You could also use JB Weld to fix it in the open position.

MattG

iTrader: (2)

Where in TX?

mazdaverx713b

iTrader: (91)

i've personally found that to be the best option. its a pretty simple job to do, it just takes a little time.

Kentetsu

Here's why I decided to leave the shaft in place, and my logic may be flawed but it seemed to make sense to me at the time:

The rear primary opening on the Nikki is slightly larger than the front. This is to make up for the airflow restriction caused by the shutter valve. I figured that if the shaft was removed, it would throw off the balance of the carb front to rear. Any thoughts on this?

perfect_circle

ive heard this argument before, and think i would lean more towards this. however for the given appliction you dont want to take anything appart and have a hard time working on it, i would suggest that you just push it open and then zip tie it, or use a bread tie...hell a paper clip would probably work.

blwfly

iTrader: (4)

wow i never really noticed that if any thing you could make the other primary equal with a dreamel..

Vashner

Thank's yall. Good tips I appreciate it.

orion84gsl

iTrader: (5)

While your correct about the size difference, the runner then narrows to the same diameter as the front primary runner underneath the shutter valve, so even if it did make a difference at the top, the lower section would then become sort of a bottleneck, so it doesnt really matter. I removed my valve and am going to enlarge the opening of the front primary, then try to do some porting of the rest of the mani, hopefully without screwing anything up. With any luck Sterling will get his manifold porting figured out soon and I can just buy one straight from him. Kentetsu, I'm PMing you about something intake related.

Jeff20B

iTrader: (13)

I removed a shutter valve from a manifold and this is how it ended up. The engine ran really nicely.

orion84gsl

iTrader: (5)

AH HA. Thank you Jeff. I accidentally got you and Kentetsu mixed up and sent him a PM regarding this stuff. You see that hole under the channel you made for the rearward runners? I think that is supposed to be Mazda's version of the channel you made, to equal out the flow the way the front channel does. I was wondering if you thought that would make any difference in the idle quality or general performance of the carb. I was just going to fill it with JB and cut the larger channel like you did.

Jeff20B

iTrader: (13)

Don't bother filling it. Too much work, not enough gain, possibility of it coming loose and making its way into the engine.

I don't use JB weld anywhere on intake manifolds. I prefer mechanical plugs where possible.

Have you seen how JB weld reacts to gas fumes? Not well. Since the intake manifold encouters fumes and liquid fuel, I'd say to avoid its use there. Lots of people use it, but that doesn't make them right.

orion84gsl

iTrader: (5)

Well actually I've only ever used it once, to install the freeze plugs in the intake coolant passages. So no, i haven't seen how the stuff reacts with, well anything. I had the stuff for over a year before I actually had a chance to use it. I have no idea what a mechanical plug is, but I'll find out. Maybe I'll just smooth out the edges, just incase it effects flow. I still have to get the proper bits for my "dremel" to get some grinding done.

orion84gsl

iTrader: (5)

Ok I just looked it up, turns out I do know what a mechanical plug is. My Freightliner uses one as a oil filler cap.

Jeff20B

iTrader: (13)

What I meant by mechanical plug is basically anything that is a physical obstruction that can't be weakened or removed under normal engine operation. Things like NPT pipe plugs or a block off plate held on with bolts or screws, and also small screws in short lengths of rubber hose. Normal engine operation won't allow these 'mechanical plugs' to dislodge and enter the engine.

Vashner

Well I finally got the shutter valved wired. It's about has half *** a job as you can do. I tried a bunch of various combos of zip ties and wires. I used a piece of a coat hanger to thread the hole and wrap around the valve then 2 linked zip's to put some tension on it. It's sad and I wonder how long before it melts. But anyway here's a pic. Someone must of taken out the rats nest before because the top middle bolt was missing and it was rusted in that area.

bliffle

I just popped the intake filter then put a cork in the hole that got rid of the honking, Two minutes. Been running fine for five years.

Vashner

Plugging the large hole does not fix a defective shutter valve.
http://www.mazdatrix.com/faq/shutter.htm

That just cuts off the air but the butterfly thing still stays closed. Correct me if I am wrong.

I have spent the last month asking about this and lot of people said wire it shut or get a SA manifold. If I did the wire shut wrong please let me know. Input appreciated.