Stupid Type 1 Carb Question

I recently replaced my idle air jets (orfice) with smaller ones after putting some Boyesen reeds in. My dumb question is: Where does the air come from to go through the idle jet? I could see a little hole in the top of the intake throat just behind the throttle valve for letting the air into the carb (I'm assuming), but I don't know how the air gets to the front of the jet, as there is a big screw and fiber washer in front of it. What is the story here?

Re: Stupid Type 1 Carb Question

From what you describe, you've got fuel jets and not air jets. The air jets let air in from the carb throat and there's nothing in front of them.

Re: Stupid Type 1 Carb Question

Oh- well this may be an embarassing revealation.:redface:

I see I made the rookie mistake in my post of not identifying my engine- 1973 Johnson 65. From what you say, it would make more sense that my idle jets are for fuel, and not air, as it does utilize a fiber (fuel friendly) washer there. I don't know where I got it in my head that these were air orifices.

In looking through my Clymer manual, there are two pictures of exploded carbs, but niether are like mine. The Seloc does a better job of showing it- I am correct in calling this a type I carb, right?


Maybe you can confim that this is indeed a fuel jet for me.(item 27) Here's my carb:



If this is the case, then thank goodness I haven't run it yet. I downsized with the boyesen reeds thinking that it was an air jet. I guess I'll probably have 3 new jets to buy.:redface:

Thanks for the help

Re: Stupid Type 1 Carb Question

Yep, you need to go the other way. Those jets deliver fuel.

Re: Stupid Type 1 Carb Question

That was fast, thanks!

Re: Stupid Type 1 Carb Question

Here's an example of an air jet (1980 115) - part #7

Re: Stupid Type 1 Carb Question

Very good. I'll pick up some #33's soon.

Cheers

Re: Stupid Type 1 Carb Question

So now that I know that these are fuel jets in my idle circuit, I have another question. Boyesen says I should go up 2 sizes (thousandths) so that would take me from my stock #31 to 33's. I could make some 33's out of my 31's, but some previous grease monkey has done a number on my 31's, and I was lucky to get them out this time. They will be retired. So I was planning on getting some 33's.

But.... I see that for my engine and carb, two choices of idle orifices are listed; #31, and #35. I usually run at sea level, so should I have had #35's in there from the get-go? Furthermore, my parts shop doesn't have 33s, but does have 32's and possibly 34's or 35's. I sure don't want to burn my reeds, so I'm trying to figure out what size to go with. Do I do the 32's or go bigger? Again, it's a '73 65hp. Thanks.

Re: Stupid Type 1 Carb Question

U-Turn, I've been following your posts. I have the same motor, a 1973 Rude 65HP. I just got back from running my Sea Level boat at 6500 and then 7800 feet during a 3 week vacation. I spent the first 2 weeks trying to make it actually run, It was my first time opening up the carbs, where I learned that I had fixed orifice's instead of adjustable needle air/fuel fuel/air mixtures. My only option was to order a propeller from nevada (100 miles from where I was, but the only option). I changed from 13-3/4 17Pitch to a 14" 13Pitch and at least my boat was able to fish from, I couldn't Idle worth a damn but I fixed that by dragging 2 5gal buckets from each corner to obtain the 2.2 MPH that was better than the 4MPH that it would barley run at, any slower and it would die.

Anyways, I did pull my idle orifice's and mine we 32's. Of course back down at Sea-Level it seems to run okay. But I spend the 3-4weeks up in yosemite area and fish from 6000 to 9000 feet, so I plan on getting a few different jets, I have the stock 32's (and whatever is in the high orifice) with the 17pitch for sea level, I guess I am going to use the 13pitch for 3000-6000ft and need new idle/high orifices, then also going to need to get a 3rd prop and idle/high jets for the 6000-10000ft.

Anyways, can you explain to me what you got, how it helped? And maybe part numbers for the 33, 34, 35, 36 idle fuel jets? as well as the matching high speed fuel jets?

Thanks in advance, I had one other question, all three of my carbs are stamped 322292 on them? What are stamped on your carbs? The numbers were on the throats just under the butterfly linkage, can you please check yours?


Thanks in advance.


-John