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Rebuilding a Polaris 3240220 Water/Fuel separator, new o-ring seals
Polaris Fuji & red Domestic engine OEM (Taiyogiken) Fuel-Water separator. Clean inside and out, rebuild with new o-rings.
Polaris part number 3240220 is the entire fuel/water separator assembly.
1) The entire insides of the separator must be squeaky clean. If there are deposits from old gasoline, clean them out. Take care not to damage the plastic bowl. Use carburetor cleaner or other suitable solvent, plus an old toothbrush or similar. You want zero grit and residue left inside. Remove the coil spring with a gentle twisting and pulling motion and clean the bottom of the plastic bowl.
Clean the outside surfaces, the hose nipples and the threads around the metal lid and the plastic cap ring while you are at it
Once clean, when re-assembled the unit must be completely air tight. That means the o-ring that seals the top must be in good (excellent condition would be preferred) condition and the inside rim of the metal top must be smooth. No gouges, nicks, or crusty accumulations. Same goes for the rim of the fuel bowl. Clean and smooth.
2) The original (polaris 3240209) o-ring (if it is still there) is likely to be quite dried out from age. I suggest replacing it even it if 'looks' OK. A new o-ring will be softer and provide a more reliable seal.
An air tight seal at the lid of the fuel/water separator is mandatory to avoid ventilation of the fuel supply. Air leaks into the fuel supply can reduce fuel pressure and fuel volume delivered to the carburetors, increasing the risk of piston lean burn and engine damage.
Note: The entire fuel system from fuel tank to fuel pump is under suction, not pressure. The fuel pump creates a suction to draw the gasoline from the fuel tank and move it through the hoses to the fuel pump at the engine. Air leaks interfere with the fuel pumping process.
3) Make sure you actually have all the pieces;
3240209 (5411051) Large upper O-ring
3240239 metal mesh fuel filter cylinder with small o-ring inside
3240238 tapered coil spring
3240240 (5432279) water indicator float ring (red)
4) The filter canister should fit snugly onto the nipple inside the lid. There should be a small o-ring tucked just inside the top of the mesh filter canister. If this needs replacement (it should be replaced if it is original) or does not seem to seal well to the lid nipple, replace it. It can be tricky to extract the old o-ring from the groove it is nestled into. I use a dental tool with a hooked end tip.
This can be replaced with either Metric 11.8mm x 2.4mm (93125K35) or 9452K23 7/16" x 3/32" -111 size. A bit of 2-stroke oil should help the new o-ring settle into place. Be sure to clean the internal groove out before installing the new o-ring. There will be dried gasoline deposits in there.
The coil spring holds the metal filter cartridge in place when assembled. The red ring is made of a plastic material that sinks in gasoline but floats in water. If there is water in the fuel supply the red ring will rise off the bottom when the water accumulates in the bottom of the separator (water sinks underneath gasoline), giving a visual indication that the fuel is contaminated with water.
Note: If you are using gasoline blended with with ethanol the presence of water can cause phase separation of the ethanol. if you see a white/milky goop in the bottom of the fuel separator, that is phase separated ethanol+water. This is not good, and typically means the fuel tank must be completely drained and cleaned.
Note: Since the separator has a permanent metal mesh fuel filter inside, there is normally no need for another external/aftermarket fuel filter elsewhere in the fuel system. The Polaris fuel system is sensitive to flow restrictions in the fuel supply. Using an incorrect or unnecessary fuel filter can result in reduced fuel pressure and cause problems.
5) When putting the separator assembly back together, smear a thin layer of 2-stroke oil onto the large o-ring to help it seat properly without stretching, tearing or distorting. If the o-ring becomes damaged, replace it. A drop of 2-stroke oil on the small inner o-ring also helps the filter slide into place on the lid nipple.
You need the plastic retaining ring to be tightened snugly enough that it does not vibrate loose while you are riding the watercraft, but do not over-tighten it so much that you risk the plastic failing.
When attaching the fuel hoses, use new high quality hoses. Also use good quality hose clamps. Oetiker type stepless/gapless ear clamps are recommended. Gear clamps sometimes do not seal the hose properly, deforming the hose itself and potentially allowing air leaks. Gear clamps can sometimes loosen over time and with vibration.
Replacement o-ring for the fuel:water separator (see next post for more info)
Measurements of a spare separator and an old o-ring I have here suggest it is a standard -224 size o-ring of 1.75 inches inside diameter, 1/8 inch thick.
McMaster-Carr 5018T261 (AS3578 Buna-N O-Ring, AS568A Dash Number 224)
While it looks like the rim inside the lid could even accept a thicker o-ring of 3/16". That would be McMaster-Carr 5018T35 (AS3578 Buna-N O-Ring, AS568A Dash Number 327)
Update: The -327 o-ring is a really snug fit. You can lubricate it and force it in there, but it is not optimal. It will difficult to get it seated when the separator is installed in the hull.
Since the fuel/water separator is actually a Japan made part, it is possible that the technically correct replacement o-ring is something Metric; perhaps 3.1 mm Width, 44.4 mm ID (McMaster-Carr 9262K767).
If someone could confirm which of these o-ring sizes do indeed fit well and most importantly, seal well, please post your comments.
Polaris part number 3240220 is the entire fuel/water separator assembly.
1) The entire insides of the separator must be squeaky clean. If there are deposits from old gasoline, clean them out. Take care not to damage the plastic bowl. Use carburetor cleaner or other suitable solvent, plus an old toothbrush or similar. You want zero grit and residue left inside. Remove the coil spring with a gentle twisting and pulling motion and clean the bottom of the plastic bowl.
Clean the outside surfaces, the hose nipples and the threads around the metal lid and the plastic cap ring while you are at it
Once clean, when re-assembled the unit must be completely air tight. That means the o-ring that seals the top must be in good (excellent condition would be preferred) condition and the inside rim of the metal top must be smooth. No gouges, nicks, or crusty accumulations. Same goes for the rim of the fuel bowl. Clean and smooth.
2) The original (polaris 3240209) o-ring (if it is still there) is likely to be quite dried out from age. I suggest replacing it even it if 'looks' OK. A new o-ring will be softer and provide a more reliable seal.
An air tight seal at the lid of the fuel/water separator is mandatory to avoid ventilation of the fuel supply. Air leaks into the fuel supply can reduce fuel pressure and fuel volume delivered to the carburetors, increasing the risk of piston lean burn and engine damage.
Note: The entire fuel system from fuel tank to fuel pump is under suction, not pressure. The fuel pump creates a suction to draw the gasoline from the fuel tank and move it through the hoses to the fuel pump at the engine. Air leaks interfere with the fuel pumping process.
3) Make sure you actually have all the pieces;
3240209 (5411051) Large upper O-ring
3240239 metal mesh fuel filter cylinder with small o-ring inside
3240238 tapered coil spring
3240240 (5432279) water indicator float ring (red)
Notes:
1994 (3240208 ) water separators apparently did not have the internal filter or did not have the red water indicator ring. If you know have additional info regarding which years/models did or did not have these parts please post a reply.
1992 and 1993 models used only an inline fuel filter (2530008 ) and did not have a fuel/water separator. If you are restoring an early model consider upgrading to the complete fuel/water separator with internal fuel filter and water indicator red ring.
Inline fuel filters were also used in some models up to 1997 (along with the fuel/water separator). The Octane also uses a single inline fuel filter.
1994 (3240208 ) water separators apparently did not have the internal filter or did not have the red water indicator ring. If you know have additional info regarding which years/models did or did not have these parts please post a reply.
1992 and 1993 models used only an inline fuel filter (2530008 ) and did not have a fuel/water separator. If you are restoring an early model consider upgrading to the complete fuel/water separator with internal fuel filter and water indicator red ring.
Inline fuel filters were also used in some models up to 1997 (along with the fuel/water separator). The Octane also uses a single inline fuel filter.
4) The filter canister should fit snugly onto the nipple inside the lid. There should be a small o-ring tucked just inside the top of the mesh filter canister. If this needs replacement (it should be replaced if it is original) or does not seem to seal well to the lid nipple, replace it. It can be tricky to extract the old o-ring from the groove it is nestled into. I use a dental tool with a hooked end tip.
This can be replaced with either Metric 11.8mm x 2.4mm (93125K35) or 9452K23 7/16" x 3/32" -111 size. A bit of 2-stroke oil should help the new o-ring settle into place. Be sure to clean the internal groove out before installing the new o-ring. There will be dried gasoline deposits in there.
The coil spring holds the metal filter cartridge in place when assembled. The red ring is made of a plastic material that sinks in gasoline but floats in water. If there is water in the fuel supply the red ring will rise off the bottom when the water accumulates in the bottom of the separator (water sinks underneath gasoline), giving a visual indication that the fuel is contaminated with water.
Note: If you are using gasoline blended with with ethanol the presence of water can cause phase separation of the ethanol. if you see a white/milky goop in the bottom of the fuel separator, that is phase separated ethanol+water. This is not good, and typically means the fuel tank must be completely drained and cleaned.
Note: Since the separator has a permanent metal mesh fuel filter inside, there is normally no need for another external/aftermarket fuel filter elsewhere in the fuel system. The Polaris fuel system is sensitive to flow restrictions in the fuel supply. Using an incorrect or unnecessary fuel filter can result in reduced fuel pressure and cause problems.
5) When putting the separator assembly back together, smear a thin layer of 2-stroke oil onto the large o-ring to help it seat properly without stretching, tearing or distorting. If the o-ring becomes damaged, replace it. A drop of 2-stroke oil on the small inner o-ring also helps the filter slide into place on the lid nipple.
You need the plastic retaining ring to be tightened snugly enough that it does not vibrate loose while you are riding the watercraft, but do not over-tighten it so much that you risk the plastic failing.
When attaching the fuel hoses, use new high quality hoses. Also use good quality hose clamps. Oetiker type stepless/gapless ear clamps are recommended. Gear clamps sometimes do not seal the hose properly, deforming the hose itself and potentially allowing air leaks. Gear clamps can sometimes loosen over time and with vibration.
Replacement o-ring for the fuel:water separator (see next post for more info)
Measurements of a spare separator and an old o-ring I have here suggest it is a standard -224 size o-ring of 1.75 inches inside diameter, 1/8 inch thick.
McMaster-Carr 5018T261 (AS3578 Buna-N O-Ring, AS568A Dash Number 224)
While it looks like the rim inside the lid could even accept a thicker o-ring of 3/16". That would be McMaster-Carr 5018T35 (AS3578 Buna-N O-Ring, AS568A Dash Number 327)
Update: The -327 o-ring is a really snug fit. You can lubricate it and force it in there, but it is not optimal. It will difficult to get it seated when the separator is installed in the hull.
Since the fuel/water separator is actually a Japan made part, it is possible that the technically correct replacement o-ring is something Metric; perhaps 3.1 mm Width, 44.4 mm ID (McMaster-Carr 9262K767).
If someone could confirm which of these o-ring sizes do indeed fit well and most importantly, seal well, please post your comments.
57.9 MPH GPS @ 6780 RPM)
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