is this part of my carb supposed to be closed?

[rooooney]

I recently had my carbs rebuilt and while putting them back on I noticed these two openings. Are they supposed to be closed with some sort of cap. the circled part-not what im pointing at. Thanks

 

[rbh]

Re: is this part of my carb supposed to be closed?

is that part of the choke assembly?
rob

 

[rooooney]

Re: is this part of my carb supposed to be closed?

yes - i believe so- i have a spare carb i bought off e-bay for parts and it's capped but i don't think mine were

 

[rbh]

Re: is this part of my carb supposed to be closed?

Ok so we are looking at the piece on the lower side on a 45 degree angle?
is it an adjustment screw or if you blow into it can you feel the air coming out in the carb somewere ?
rob

 

[ziggy]

Re: is this part of my carb supposed to be closed?

two types of auto chokes i know of. one is electric. you don't seem to have wires. the other is a stove pipe type. the stove pipe type has a pipe that fits into that hole in your auto choke. the other end of that pipe, on my boat anyways (2GC carb) fits into a hole in the manifold and goes maybe 6 in. down. it picks up the heat and the heat rises up the tube into the choke and warms the bimetal spring so it winds up or unwinds depending on weather it's cold or hot. so that's my speculation. a stove pipe goes in that hole..

 

[rooooney]

Re: is this part of my carb supposed to be closed?

It is not electric- the opening leads into the choke thermostat but there appears to be another mechanism for adjusting the spring

 

[rooooney]

Re: is this part of my carb supposed to be closed?

this is a picture of my spare carb- It has a sealed cap over this tube- where the carbs on my boat do not- ??

 

[ziggy]

Re: is this part of my carb supposed to be closed?

It is not electric

that's because ya got the stove pipe type.

there appears to be another mechanism for adjusting the spring

yep, on my auto choke there's a spec as to where to set that adjustment. in my case. ya set the hash mark in the middle. this is how you adj. how much the choke goes closed. i believe there's also a specification as to how much space is left open after the choke is closed by the cold spring. as it warms up the spring unloads and allows the coke to go to full vertical and full open..

the stove pipe that you don't have is what warms that bimetel spring making it unwind.

here's a pic i took to show a manifold leak. but in it you can see the remenents of the stove pipe..

here's a pic of the stove pipe connected to my carb. it the part wrapped in cloth..

hope that helps..

 

[rooooney]

Re: is this part of my carb supposed to be closed?

There seems to be one hole in the manifold that the choke could run into- do you think that the two carb or choke inlets could connect before heading down that hole? Thanks for the great pics by the way ziggy- what would you recommend using to run the inlet to the manifold?

 

[ziggy]

Re: is this part of my carb supposed to be closed?

There seems to be one hole in the manifold that the choke could run into- do you think that the two carb or choke inlets could connect before heading down that hole?

i don't know. personally, i'd refer to my oem service manual to find out the answer to that question. if there's truely only one hole for a pipe. speculation would be that they must connect together prior to going off to the carbs. of course that's only a guess. i've not seen a dual carb set up w/stove pipes. so i've really no idea... just a guess..

what would you recommend using to run the inlet to the manifold?

on my last boat, that stove pipe had rusted off right at the top of the manifold. if memory serves me, i think i just used some break line bent to fit. + i had to drill out the rememnts of the old pipe to get a new one stuffed into the hole. i don't think i drilled real deep. just deep enough to get the pipe in the hole and support it + direct the heat up to the auto choke... when i did that, i had no idea where that pipe went in the manifold. so i didn't drill real far in because i didn't know what i was drilling into... i just knew i needed to get the heat rising to the choke..

 

[dan t.]

Re: is this part of my carb supposed to be closed?

why bother fooling around with hot air tubes that will just rust away again, put an electric choke thermostat on and be done with it

 

[rooooney]

Re: is this part of my carb supposed to be closed?

So i just took a real good look at my carb and there is a open route from the manifold (where it bolts on) to the choke. Could that be where it gets its heat or is this something else?

 

[KJSmitty]

Re: is this part of my carb supposed to be closed?

The "passage" you found is a vacuum source to the choke housing. Typically this small vacuum source is what "pulls" the hot air up that hot air riser tube Ziggy has been describing etc.

I too have used old brake lines for these as well as 1/4 inch copper tubing and fittings from the local hardware store.

Good luck

 

[Robj]

Re: is this part of my carb supposed to be closed?

i believe there should be a bi-metal spring inside the part where the stove pipe goes to that opens/closes the choke. If you don't have that spring, might as well block off the hole for the stove pipe since the choke will not work.

Have a great day

Rob.

 

[KJSmitty]

Re: is this part of my carb supposed to be closed?

Good point, without the spring everything else would be near useless..


The coil/spring however is typically housed in the black choke cover.

Cheers

 

[rooooney]

Re: is this part of my carb supposed to be closed?

This is just my spare parts carb- I do have the spring and cover on both carbs

 

[BigDaddy5517]

Re: is this part of my carb supposed to be closed?

Well I have a 120hp dual carb setup also and I only have a tube from the manifold to the forward carb. The rear carb has the choke hole capped... The cap is plastic with red permatex on it and its doesn't look stock.... I just took the carbs off today and will be rebuilding them tomorrow and was wondering if I need to figure out a way to hook up both chokes. Is it ok to use only one choke? I also have never seen a dual carb system setup like this. Thanks

 

[rooooney]

Re: is this part of my carb supposed to be closed?

Smitty when you say brake line did you mean rubber line?

 

[ziggy]

Re: is this part of my carb supposed to be closed?

when you say brake line did you mean rubber line?

no, metal brake line. it needs to be small in outside dia. to go into the hole in the manifold. use a tubing bender to bend it to your desired dimensions..