'74 50hp carb kit help

[Rulost]

I've been searching for a while, and am having a hard time figuring out which carb kit is right for my engine. Serial Number 3817126. Looking at several different sites is only adding to my confusion. One shows a Sierra 18-7013 covering all from 1961-'75, another shows a quicksilver 1395-9262-1. Looking at iboats, I can't find either of these numbers or a definite way of determining which kit (or neither) is right for my application. Thanks for any help!

 

[Chris1956]

The crowleymarine website shows parts by serial number. If I assume you have a US serial number,it shows you have sidebowl carbs, which were widely used.

http://www.crowleymarine.com/mercury-outboard/parts/449_10.cfm?mdl=IYRXGI.

 

[Rulost]

Thanks Chris, I will get them ordered.

 

[tommarvin]

Please clean out all the small tubes and openings,jets with spray cleaner, and blown clean and dry with air,blow air in all tubes and openings.

Free outboard service manuals at www boatinfo.no/lib/library.html click on your motor maker, find your carb.Rebuilding a carb is not that easy, focus when you take it apart,take pictures, and you have the manual.

 

[Rulost]

Thanks Tom, I already have the manual downloaded and used it when I had the powerhead off replacing gaskets and seals. Appreciate the advice, I actually find carbs easy to rebuild and have a lot of experience with auto, atv, and small engines, just never pulled a 2 stroke outboard carb yet. My biggest concern was all of the part number changes over the years and reading stories on here of kits not being right when they came in.

 

[Chris1956]

Those sidebowl carbs have several pinholes on the inside front part of the throat. Spray into the idle air intake and see that those holes are clear.

 

[Rulost]

Thanks I will make sure to check that. Just got the carb kits in today, so hope to knock it out Saturday. I'm pretty sure either the needle/seat is worn out, or the float is leaking. Boat runs great, but loads up at idle and fuel comes out of the top carb float bowl. As long as I am throttled up on the water, there is no issue. It sat for several years before I put it back in use. Carbs had been drained well, but I would think the needle/seat is not sealing properly.

 

[Chris1956]

The original floats were foam. The alcohol in today's fuel tends to dissolve them. The replacement floats should be hard plastic. Those can crack. Make sure each float has a small spring on it's top. If the floats look suspect in any way, replace them. Replace the inlet needles and seats as well, as the old ones were brass and rubber. The new ones are all brass with neoprene-tipped inlet needles.

 

[Rulost]

Finally had time to pull the carbs today and start tearing down/soaking in cleaner. Floats are plastic, and needles are neoprene tipped, so they have been apart before. If it hadn't been for the loading up at idle to the point that it stalled the engine, I would have had no reason to tear it down. Boat ran perfect otherwise. Trash in float bowls, keeping needle of top carb stuck open just a bit. At least I did find that whoever did this job before could have adjusted the carbs a little better. Throttle plates could have been adjusted to open a little further at full throttle. Ran 32 on GPS, so I didn't worry about it too much. Will take care of that when I put it back together

 

[Rulost]

Quick follow up since it drives me crazy when threads just kind of end with no results. Carb rebuild was easy, wish removing/installing was as easy. Not a lot of room in there for fingers with distributor, etc in the way. When I put it all together and started to set everything up, throttle plate broke where screw goes through, so had to order a new one. Got everything running good in a barrel now, with no more leaks. Waiting for a little better weather to take it to the lake for further testing. Thanks for the help and tips, will touch back after I get the boat wet.

 

[gm280]

Quick follow up since it drives me crazy when threads just kind of end with no results. Carb rebuild was easy, wish removing/installing was as easy. Not a lot of room in there for fingers with distributor, etc in the way. When I put it all together and started to set everything up, throttle plate broke where screw goes through, so had to order a new one. Got everything running good in a barrel now, with no more leaks. Waiting for a little better weather to take it to the lake for further testing. Thanks for the help and tips, will touch back after I get the boat wet.

Well that is good news. And I want to thank you for posting back with results. I too hate to read threads that just end without any results or how things worked out. So thanks again. :thumb: