Gas is spitting out tne vent hole on an 32mm mikuni carb when it running at 1/4 or more throttle. elan 250 single cylinder skidoo

Bad injector possibly? Do a compression test and verify you don't have a bad valve.

indicates problem floats or needle and seats
take the carbys to a specialist carby shop and have them full reconditioned

Hey Anon,, WHY are you needing to replace the carb?? In my 40+ years of being a motorcycle/atv mechanic, I have only replaced 3 carbs,,,and CLEANED and repaired HUNDREDS AND HUNDREDS. reply to me on here.... I'll help you

standard carbys will cover a .020 oversize bore
melted piston is from detonation which is lean mixture or incorrect ignition timing
the oil will be a metered amount so it will be correct for all rpm
items like incorrect float level and air filter are the suspect causes

the ajustment need to be set where they were originaly, needle position and mixture screw. the carbs are not suppling enofe fuel, was there any torn seals or diaphrams.

The needle valve is stuck, you will have to get the carb. off and check the float and needle assy.

That was an atmospheric vent you found that should not have gas in it. If it does, the carb has over flowed. It probably needs to be cleaned with special attention paid to the needle valve and float assemblies.It is routed up high to prevent water and debris from entering it and clogging it up. It should have holes for it to pass through on the snorkel coming out of the air box behind the gas tank under the seat.

Install a new NGK spark plug ONE HEAT RANGE HOTTER THAN STOCK . Now go back to the 32/1 gas mix. The 32/1 is what lubricates the crank bearings and piston. At 44/1 you are asking for a seized piston and/or the need for new crank bearings. Be sure to use Two Stroke Engine Oil in the gas, NOT motor oil. Use premium gas, not regular. This should take care of plug fouling.

Remove the float bowl and clean the entire carb with a spray carb cleaner from the auto parts store. Wear protective goggles to avoid getting spray in your eyes. Spray all the little airways and fittings in the carb. Remove the two screws on the outside throat of the carb and spray into the screw holes as well.

Be sure to put these two screws back in the same hole they came out of. IMPORTANT > do not tighten these two screws down. Only screw these in until they LIGHTLY seat. Now turn each screw one and one half turns outward. Put the rest of the carb back together, clean the air filter and install the carb. Let the float bowl fill then start the engine. This process should get you back on the road.

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