Carburetor rebuild

LindenLongRods

Petty Officer 2nd Class
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Jul 10, 2007
Messages
192
I have 88 Spl 1987, is the carburetor rebuild tough? I have to go through the air filter assembly 1st ? If anybody has diagrams or can help me, I would be grateful. I rebuilt the water pump so I m not completlety useless and I have seloc manuel. Is that any good? Also maybe someone have video?? The motor runs on muffs but with back pressure in water it won't unless open butterfly
 
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interalian

Commander
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Jul 23, 2009
Messages
2,105
Not hard. Need to take the silencer cover off, then the silencer body. Disconnect cables and linkages then unbolt the carbs. Careful you don't bend the linkages - they pop out of the nylon grommets fairly easy with a twist of a medium screwdriver.

Get proper rebuild kits from BRP. Need to remove the welch plugs inside the fuel bowls to access the idle passages for a proper clean. Lots of spray carb cleaner through all the passages and blow it out. Make sure you can see the air come through all the ports to be sure they're clean.
 

racerone

Supreme Mariner
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Dec 28, 2013
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38,553
There is not much that goes wrong with these carburetors at all.----What is the motor doing / not doing ?-----Compression test done ?
 

David Young

Chief Petty Officer
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Jul 12, 2015
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485
My biggest problem was figuring out how to remove the linkage on the carbs. I found a youtube video of a guy removing the linkage and it 'all made sense after viewing it. Take a lot of pictures before you start removing things, you will be OK :)
 

Joe Reeves

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Feb 24, 2002
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13,262
Take pictures... Make notes. You think of course "I'll remember where and how that goes"... No, you won't! :)

The only movable inside the carburetor is the float, easily adjusted as follows below.

There's normally no need to remove any of the core plugs... BUT.. if required, carefully cave in the center of the core plug, then pick it out. Use extreme care that you DO NOT damage the carburetor surface that exists under it. After caving it in, I usually create a small hole in it so that I can insert a pointed scribe to flip it out. Installing a core plug is simply a matter of sitting it in position, then flattening it out somewhat with a proper size punch.

That carburetor has brass fixed jet (no adjustable needle valves). Any jet that you can see on the outside portion of the carburetor measures "Air".... a hidden jet installed in a fuel passageway of course measures "Fuel". The sizes are marked on the face of the small jets... and on the sides of the larger long jets. Make a note as to which one goes where... type, size, location. They may look identical... some are, some aren't.

The 1987 88hp has two dual barrel carburetors. Inside each throat, in the top area, near the front, is a small "air bleed" jet (2 to a carb)... the high speed jet is located horizontally in the bottom center portion of the float chamber... way in back of the drain screw, secured via 1/4x20 threads. Carefully clean the high speed jet with a piece of single strand steel wire as solvent and air just doesn't do that job properly.

DO NOT use any kind of sealer on the carburetors gaskets for obvious reasons.

.********************
(Carburetor Float Setting)
(J. Reeves)

With the carburetor body held upside down, the float being viewed from the side, adjust the float so that the free end of the float (the end opposite the hinge pin) is ever so slightly higher (just ever so slightly off level) than the other end. And when viewed from the end, make sure it is not cocked.
********************************

When installing the carburetors, adjust the linkage that connects the two throttle butterflies so that there isn't any play (sync). You want "all" the throttle butterflies to open and close at the same time. You DO NOT want one butterfly closed at idle and one ever so slightly open!

The throttle butterflies should just start to open when the scribe mark on the metal cam is aligned dead center with the throttle roller... not before or after!
 

interalian

Commander
Joined
Jul 23, 2009
Messages
2,105
There is not much that goes wrong with these carburetors at all.----What is the motor doing / not doing ?-----Compression test done ?

Quoted for truth. The carbs on my '82 didn't get rebuilt for 30 years and were still clean when I finally broke down and put rebuild kits in them. Mine was a low hour motor and always run completely out of fuel before storage.

If you're planning to remove any jets, make sure you have a proper tool, not a screwdriver. Need to have flat, parallel and thick flanks so it won't distort the slot and spread or gall the brass. I made this from a screwdriver with the correct OD (middle tool):

IMG_0785_zpsbeohuzof.jpg
 

LindenLongRods

Petty Officer 2nd Class
Joined
Jul 10, 2007
Messages
192
racerone It is not starting in the water, on the muffs is good, alot smoke to. So I think either rebuild or adjustment
 
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