Thermostat housing hole.

Sea Rider

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When all 3 seats have been micro polished to mint cond check if all floats rests slight under or not which won't be an issue as long the needle's tip and seat are doing their homework right. Check that all seats rests fully down against carb body ? On non hinged carb floats, the height will be determined by the float, needle tip and seat condition.

Happy Boating
 

Douglasdzaster

Petty Officer 3rd Class
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Sep 11, 2020
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When all 3 seats have been micro polished to mint cond check if all floats rests slight under or not which won't be an issue as long the needle's tip and seat are doing their homework right. Check that all seats rests fully down against carb body ? On non hinged carb floats, the height will be determined by the float, needle tip and seat condition.

Happy Boating
can make out the number on the jet it’s to screwed up. It is the middle carburetor. The company that I corresponded with told me it was a 120 but Yamaha discontinued and said I could try a 125. Here’s the float on #1 carburetor. I should be able to compare it with at least one more today when finished cleaning.
 

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Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
10,855
The float on carb one looks fine to me. The middle carb used to work with 3 different jet numbers which were : 115-120-125 while the slow jet remained 60 numbered on all 3 carbs. Is 115 the jet number stamped on 1-3 ? On many 3 carbed motors have seen one jet having a smaller or higher jet number than the other 2 not necessarily being the middle one. Factory tech issues.

Happy Boating
 

Douglasdzaster

Petty Officer 3rd Class
Joined
Sep 11, 2020
Messages
84
The float on carb one looks fine to me. The middle carb used to work with 3 different jet numbers which were : 115-120-125 while the slow jet remained 60 numbered on all 3 carbs. Is 115 the jet number stamped on 1-3 ? On many 3 carbed motors have seen one jet having a smaller or higher jet number than the other 2 not necessarily being the middle one. Factory tech issues.

Happy Boating
I couldn’t make out the numbers. Will have a magnifying glass tomorrow and see if that helps. They had told me my motor had the 120 but not available and that their technician said better to go up than down. I’ll try looking at the numbers again tomorrow. Who ever before me had already scared up some of the jets probably using the wrong screw driver. Just for kicks I put the float on carburetor 2 last night and it stood way up like they all did when I removed them. This morning I finished cleaning and polishing #2 and now the float sits down just like the first one. All that polishing really makes a difference. Anyway number 3 is not damaged maybe I can polish and read that number but I’ll look at both with the magnifying glass.
 

Sea Rider

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Both 1-2 seats must have been really dirty, huge gunk accumulation on top for floats now to sit bit downward. If the tech said to go for a 125 jet must know his business well to end running 115-125-115 jets in that order when the carbs are installed back.

You can screw a jet head if severely stuck while trying to remove it with a wrong screwdriver head. A shade tree pseudo mechanic work for sure.

Happy Boating
 

Douglasdzaster

Petty Officer 3rd Class
Joined
Sep 11, 2020
Messages
84
Both 1-2 seats must have been really dirty, huge gunk accumulation on top for floats now to sit bit downward. If the tech said to go for a 125 jet must know his business well to end running 115-125-115 jets in that order when the carbs are installed back.

You can screw a jet head if severely stuck while trying to remove it with a wrong screwdriver head. A shade tree pseudo mechanic work for sure.

Happy Boating
1and3 are 115 jets. Unfortunately everywhere I checked the 125 is at least a month away in Japan. Unless you have a source I may have to leave it for now.
 

Douglasdzaster

Petty Officer 3rd Class
Joined
Sep 11, 2020
Messages
84
Both 1-2 seats must have been really dirty, huge gunk accumulation on top for floats now to sit bit downward. If the tech said to go for a 125 jet must know his business well to end running 115-125-115 jets in that order when the carbs are installed back.

You can screw a jet head if severely stuck while trying to remove it with a wrong screwdriver head. A shade tree pseudo mechanic work for sure.

Happy Boating
You’re right about those seats I’ve spent several hours on each one until the cotton came out clean. I tried to remove them with a thin wall 10 mm socket and they don’t want to budge. I was going to inspect the little o ring on the end of them. Hopefully they’re ok. No telling how old the seats are. I know I can blow on the fuel intake with my mouth and they’re not leaking until I turn the carburetor back over then they open so I guess they’re fine.
 
Last edited:

Sea Rider

Supreme Mariner
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Sep 20, 2008
Messages
10,855
Never had same issue with a leaking carb after the seat was micro polished to new condition along new bowl gasket install. If the needle/seat closes fine while blowing air through the carb intake, expect the same when priming the fuel bulb till firm. Hope the removal of the screwed jet at the machine shop it's an easy fix to access and remove the nozzle located under it and once perfectly cleaned and shinny install the new 125 jet in.

So it was not just a motor restoration as I thought, it's the entire boat, motor, trailer package, long DIY work, but as long you're having fun go for it.

Happy Boating
 

Douglasdzaster

Petty Officer 3rd Class
Joined
Sep 11, 2020
Messages
84
Never had same issue with a leaking carb after the seat was micro polished to new condition along new bowl gasket install. If the needle/seat closes fine while blowing air through the carb intake, expect the same when priming the fuel bulb till firm. Hope the removal of the screwed jet at the machine shop it's an easy fix to access and remove the nozzle located under it and once perfectly cleaned and shinny install the new 125 jet in.

So it was not just a motor restoration as I thought, it's the entire boat, motor, trailer package, long DIY work, but as long you're having fun go for it.

Happy Boating.
 

Douglasdzaster

Petty Officer 3rd Class
Joined
Sep 11, 2020
Messages
84
Nothing fancy but it’s paid for and I’m fix it up the way I want. Motor was the biggest issue. I’ll be on the water soon as I get it back together. Then I can take my time on other things.
 

Douglasdzaster

Petty Officer 3rd Class
Joined
Sep 11, 2020
Messages
84
Question sir. I almost messed up with the slow jets #60. The third one clogged and I couldn’t get a tooth pick to work. So I thought I’d compare it to the others and when I ran a toothpick in them they clogged as well. I don’t know if it’s toothpaste I missed or what. Anyway my question is does the hole in those jets bottle neck or do they stay the same size all the way through? I got one open and either that’s the case or it still has some blockage. The holes on the sides are all clear.
 
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