86 merccarb 2bbl. Purpous of this orrifice ???

[paultjohnson]

Had flame arrester off for a bit. [Driveway] Got windy. Noticed a speck of debris down the hole in this orifice. Looked about 1/8 in sq at the most. Wasn't able to retrieve it. Yet. Looked almost like a tiny corner of a license tag??? Greenish, maybe reflective.?

Questions.
Might it be piece of gasket, or, or did it blow in ?

What does that orifice do. ? Can I just leave it? Not worried about it going thru engine as it was small and-softish- looking.

Would appreciate any thoughts. Thank you

 

[Don S]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

Fuel bowl over flow in case the needle valve sticks open. The fuel goes into the engine, not outside like the automotive version would.

 

[achris]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

That orifice leads directly and unfilteredly(?) into the float chamber... If any debris goes in through there, there is a chance (read: high likelihood) that it will find its way to one of the jets or the accelerator pump... Given that the jet sizes are way smaller than the debris (you say 1/8" sq) it will cover the jet, leading to run condition problems....

Personally, I would remove the carbie, strip it down and give it a good clean out.... And while you're in there, check all the settings...

Chris........

 

[paultjohnson]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

Fuel bowl over flow in case the needle valve sticks open. The fuel goes into the engine, not outside like the automotive version would.

Ahhh So I can just leave it be. Thank you very much!

 

[achris]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

Ahhh So I can just leave it be. Thank you very much!

Errrr, NO! Read my last...

 

[paultjohnson]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

That orifice leads directly and unfilteredly(?) into the float chamber... If any debris goes in through there, there is a chance (read: high likelihood) that it will find its way to one of the jets or the accelerator pump... Given that the jet sizes are way smaller than the debris (you say 1/8" sq) it will cover the jet, leading to run condition problems....

Personally, I would remove the carbie, strip it down and give it a good clean out.... And while you're in there, check all the settings...


Chris........

K Now i not sure ... I hate to tear open the carb now now. But If I have to i Will. I need a little more clarification ?

 

[Don S]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

I couldn't really see the debris you were talking about. If you can, suck it out with a shop vac with a reduced hose. or tweezers or something.

 

[achris]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

K Now i not sure ... I hate to tear open the carb now now. But If I have to i Will. I need a little more clarification ?

I don't think I can be much more clear.... That hole leads to the float chamber. The float chamber is where all the petrol is that will be going to the jets... Anything in that chamber (usually only petrol, but now a small piece of debris too) WILL make its way to a jet eventually....

Chris......

 

[achris]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

I couldn't really see the debris you were talking about. If you can, suck it out with a shop vac with a reduced hose. or tweezers or something.

It's slipped inside. He was unable to retrieve it.... It's now in the float chamber.... :facepalm:

 

[paultjohnson]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

The debris was down in the hole. That long narrow one gets small like a pencil. Wont see in pic Tried vacuum . There is a chance i got it But I was using a clear small hose on didnt see it fly by May have not seen it. I also tried a toothpick thing w a tiny bit of greese on it. Couldnt grab it. Now I cant see it. Its either farther in . Or it did get sucked out Part of my delima

 

[paultjohnson]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

It's slipped inside. He was unable to retrieve it.... It's now in the float chamber.... :facepalm:

Can I just take the top off of the carb and do a jiffy buff kiddie punk job for now And do a full rebuild later after the season?

 

[paultjohnson]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

I don't think I can be much more clear.... That hole leads to the float chamber. The float chamber is where all the petrol is that will be going to the jets... Anything in that chamber (usually only petrol, but now a small piece of debris too) WILL make its way to a jet eventually....

Chris......

What I mean by not sure is Reading Dons post I understands it to mean the fuel comes up that orrifice if bowl overfills, and runs into the engine I assumed by down the carb throat. I read yours as going the other way into the carb So I confused

 

[achris]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

Can I just take the top off of the carb and do a jiffy buff kiddie punk job for now And do a full rebuild later after the season?

If that's what you want to do.... But have a read of the blue type in Don's signature.....

 

[paultjohnson]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

I also understand a agree with doing it right;' anything right. Ive been working on my boat for 2 weeks, all seats out. carpet clean, upholesryy repair. Will send pics ! But I wanna boat now , summers just starting like yesterday ! I hear about the 50 /50 success rate on rebuilds, and the fact that it starts perfect and runs good, Makes me want delay this project. If feesable.

 

[paultjohnson]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

Sooooo Does fuel come up and just spill down the throat of the carb in the event of fuel overflow FROM the bowl ? As I understood Dons post . Then leaving the debris would be harmless
OR
Does it supply fuel TO the bowl ? acris.. ? BAD I know ...Then I'm tearing my carb apart.

Maybe I misread something Im gonna reread.

 

[achris]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

If the carbie is working well now, then opening it up and cleaning it is not going to change that unless you do something wrong... How long will it take? An hour, max.... or you could be out on the water, at the beginning of a beautiful day....that little bit of debris finally finds a jet to land against... and the engine quits, or runs so poorly that you need a tow to get back to the dock..... Suddenly, that hour is going to look like a great investment...

Just saying.... roll the dice... take your choice....

Chris.....

 

[achris]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

Sooooo Does fuel come up and just spill down the throat of the carb in the event of fuel overflow FROM the bowl ? As I understood Dons post . Then leaving the debris would be harmless
OR
Does it supply fuel TO the bowl ? achris.. ? BAD I know ...Then I'm tearing my carb apart.

Maybe I misread something Im gonna reread.

That tube/orifice has 2 functions... One as Don said, an overflow if the needle stick open. The other is the vent for the float chamber. So, in normal operation air is drawn in and expelled through it as the fuel level rises and falls (just like the vent fitting in your fuel tank). IT OPENS DIRECTLY INTO THE FLOAT CHAMBER... Anything going in through there is going into the float chamber....

 

[paultjohnson]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

If the carbie is working well now, then opening it up and cleaning it is not going to change that unless you do something wrong... How long will it take? An hour, max.... or you could be out on the water, at the beginning of a beautiful day....that little bit of debris finally finds a jet to land against... and the engine quits, or runs so poorly that you need a tow to get back to the dock..... Suddenly, that hour is going to look like a great investment...

Just saying.... roll the dice... take your choice....

Chris.....

Chris Howdy ! Please read post 2 from Don Maybe you will see my confusion. I very much respect both of your thoughts. But right now, in MY [maybe feeble brain] your and Dons posts are a bit contradictory. Am I missing something ?

 

[paultjohnson]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

That tube/orifice has 2 functions... One as Don said, an overflow if the needle stick open. The other is the vent for the float chamber. So, in normal operation air is drawn in and expelled through it as the fuel level rises and falls (just like the vent fitting in your fuel tank). IT OPENS DIRECTLY INTO THE FLOAT CHAMBER... Anything going in through there is going into the float chamber....

See now there is some clarification Ok that helps ... Dang ! Thanks guys.. Will check in tomo.

 

[achris]

Re: 86 merccarb 2bbl. Purpous of this orrifice ???

Chris Howdy ! Please read post 2 from Don Maybe you will see my confusion. I very much respect both of your thoughts. But right now, in MY [maybe feeble brain] your and Dons posts are a bit contradictory. Am I missing something ?

Not at all... What Don said is correct... He was just telling you one of the functions of the vent tube (that's what that orifice is called) and why it's like that (as opposed to a normal automotive carbie)... I have been making comment on the ramification of your piece of debris.... All the time you have spent debating the subject here you could have been out there and had the job done by now....

Cheers,

Chris..........