Replacement carb jets on old motor

[BrounHownd]

So I have a 1982 Mariner 40EL, which is a 2 cylinder with 2 Keihin carbs.

I was working through the carbs to clean, rebuild, and learn--and buggered one of the main jets, as it was stuck--after the top cracked, had to use an ez-out to remove it. Crowley lists the part number as 42437M Jet, Main (#170). Not available anywhere I can find. This is a learning process for me--probably shouldn't have started on something with hard-to-find parts, but it is what it is.

I have the Quicksilver rebuild kit 97667T on the way (not from Crowley, not at that price), but looks like that contains needles and seats--no jets.

The jet most closely matches the "Keihin Vintage Main" as far as the listed dimensions, but they don't offer a 170 version.
https://jetsrus.com/a_jets_by_carburetor_type/jets_keihin_vintage_main_3D.html

I know that there are aftermarket jets available and rejetting kits and the like. Any advice as to where I can find a serviceable replacement would be much appreciated--or am I on to buying an entire carb? I won't be attempting to pull the other one until I know I can find the parts--will just soak and blow air.

Thanks in advance for any guidance.

 

[MrGiggles]

Is there a part number or series stamped on the carburetors or in the service info? That might you find a jet from Keihin.

 

[Pappy]

I have used JetsRUs several times through the years on motorcycle carburetors that I get in to. They have been most helpful in determining what is what on identifying jets.
As I remember they are not easy to get ahold of but most helpful once you do make contact.
Let us know as you progress with this.
Have you tried Ebay with the part number?

 

[BrounHownd]

Is there a part number or series stamped on the carburetors or in the service info? That might you find a jet from Keihin.

The only info that is stamped is the Kaihin logo, 6E900 (part of the Mariner serial number pattern for the motor it seems) on both, and UE 28 (bottom) and UF 21 (top). These markings are on the flange that bolts to the head/manifold.

I'll try to find a way to connect with them directly. Thanks!

 

[BrounHownd]

I have used JetsRUs several times through the years on motorcycle carburetors that I get in to. They have been most helpful in determining what is what on identifying jets.
As I remember they are not easy to get ahold of but most helpful once you do make contact.
Let us know as you progress with this.
Have you tried Ebay with the part number?

I may send them a request and see where I get. Maybe one of those smaller ones can be drilled out?

Ebay was no dice right now on the main jet. The slow jet is available sometimes, but not in need at the moment.

I found a used whole carb on the one I buggered for a reasonable price--have it on the way and will clean and rebuild it along with the existing bottom one while I chase down this jet. Gonna clean all the other jets in-situ until I know where to get parts.

 

[MrGiggles]

Is there a part number or series stamped on the carburetors or in the service info? That might you find a jet from Keihin.

The only info that is stamped is the Kaihin logo, 6E900 (part of the Mariner serial number pattern for the motor it seems) on both, and UE 28 (bottom) and UF 21 (top). These markings are on the flange that bolts to the head/manifold.

I'll try to find a way to connect with them directly. Thanks!

The service manuals may have some info in their data charts.

The Mikunis on my Suzuki are just stamped with jibberish, but the model and series is listed in the service manual.

 

[maintenanceguy]

I have the same motor. Last summer, I bought a pair of used carbs from ebay for $50. I was able to combine parts from my original carbs with the ones I bought and ended up with two good working carbs.

I just ordered a water pump housing for the same motor from ebay. I'm sure I'll have to replace the motor in a couple of years because I won't be able to get parts anymore.

 

[BrounHownd]

So I ended up ordering a whole top carb unit from ebay. Will keep looking for a jet solution, but at least the boat is running now as it warms up.

Went through both last night, cleaned them with jets in place, put in an OEM rebuild kit. The whole reason I started down this road is the damn motor suddenly wouldn't idle well, and would stall as soon as it was dropped into gear. Bought the boat a month ago as a project, and it ran fine the first two trips out, but of course, on the first family trip, it starts to act up. Had fuel dripping from the carbs at idle.

Replaced the fuel pump, the diaphragm was about to fall apart, and when I pulled the float valve from the bottom carb that came off the boat, found this: https://imgur.com/a/ticXNpG

Just fired it up and it's idling, albeit not smoothly, but it's running and will shift without dying. Planning to put it in the water tomorrow to tune it under load and go for a test idle around the cove. May even wet a line or three.

I'm sure I'll have to replace the motor in a couple of years because I won't be able to get parts anymore.

This worries me, too. But I figure in a year or two if I hit a major parts issue, I can part it out to guys like you and me and subsidize an early 2000s repower.