Aquascooter is the only engine designed to run under water.
AQUASCOOTER WILL NOT START
Just one small water breach will cause it to stop running, yet on the bench it may appear to run perfect.
When servicing an Aquascooter short cuts just do not work. Do it right the first time. We’ve been selling and servicing Aquascooters for 36 years. We’ve learned quite a bit in that period of time. We have prepared this helpful information for your review.
AS-400 & AS-450 are 31 to 36 years old. The seals and gaskets are just too old to hold up any longer under water, even if unused for many years. A full rebuild is the only way to go. Replace all seals, gaskets, “O” rings. Rebuild the carb, bottle hone cylinder & check cylinder and piston for scores, if found they must be replaced, install new rings, upgrade to electronic ignition (easy), replace exhaust valve, plug boot and spark plug. This includes rebuilding the starter assemble, replace the water seal under pulley, “O” ring, ignition wire grommet and starter spring. On AS-400’s the muffler must be opened, clean out muffler parts (not used in later models) and replace with new “O” rings without any of the original muffler parts replaced.
AS-500’s are 25 to 30 years old, depending on use and condition we have found most to require a full rebuild, but not all. The minimum to consider is to rebuild the carb, replace exhaust valve, spark plug, plug boot. Compression should be 126-lbs. 5-lbs or less is borderline low. If low, bottle hone cylinder and replace rings and head gasket. This can be done without taking the full engine apart. Listen for bearing whine that indicates water was left in engine and a full rebuild is needed as noted for the AS-400/450.
AS-600’s are 9 to 24 years old, rebuild carb, replace exhaust valve, spark plug and plug boot and all hoses
AS-650, were introduced in 2006 with the “CE” model, Super-Magnums in 2009. Replace exhaust valve and spark plug yearly. Carb may need rebuilding depending on age.
In general for all models: Carb diaphragms and gaskets are only good for 5/6 years, replace spark plug and exhaust valve once a year. Replacing the exhaust valve every year is a must even if the Aquascooter was not used.
Only use Aquascooter special oil, since Aquascooters are the only engine to run cold. It’s formulated for its cold running requirements.
AQUASCOOTER OWNER, PLEASE TAKE NOTE OF THIS IMPORTANT INFORMATION
Your aquascooter when shipped to you has it’s spark plug boot packed with grease to be sure the boot is 100% sealed and will not short out the ignition system in the water. It is important that you check the spark plug boot for grease before each use. Failing to perform this boot check can result in your electronic ignition system shorting out. Such a failure will not be covered under our warranty.
AQUASCOOTER QUICK TIPS
STARTING YOUR AQUASCOOTER
1. DO NOT TURN ON THE CHOKE UNTIL YOU HAVE PULLED THE ENGINE OVER THREE TO FIVE TIMES, AND IT DID NOT START. NOW WITH THE CHOKE IN THE START POSITION PULL THE ENGINE OVER UNTIL IT STARTS (DEPENDING ON THE PRIME IT COULD BE 6 TO 20 PULLS). AS SOON AS THE ENGINE STARTS TURN OFF THE CHOKE TO THE RUN POSITION. IT MAY DIE IF YOU DID NOT TURN OFF THE CHOKE QUICK ENOUGH. DO NOT ADD CHOKE AGAIN. PULL ONE OR TWO TIMES AND YOUR ENGINE WILL START. REMEMBER, NEVER PUT ON THE CHOKE UNLESS IT DOES NOT START IN 5 PULLS. MOST AQUASCOOTERS WANT TO START IN ONE OR 2 PULLS EVEN 6 OR MORE MONTHS AFTER IT WAS LAST USED.
2. DO NOT LET YOUR AQUASCOOTER SIT IN THE HOT SUN, TRUNK OF YOUR CAR, OR BILGE OF YOUR BOAT IF IT IS HOT. THIS WILL CAUSE VAPORS FROM THE FUEL TANK TO BE FORCED INTO THE AIR CHAMBER CAUSING A FLOODED SITUATION THAT WILL PREVENT YOUR AQUASCOOTER FROM STARTING.
3. IF YOUR AQUASCOOTER DOES NOT START, CHECK YOUR AIR CHAMBER FOR A FLOODING CONDITION. THE AIR CHAMBER WILL BE RICH IN GAS VAPOR AND POSSIBLY HAVE FUEL SITTING IN THE BOTTOM OF THE CHAMBER. IF YOU FIND THIS CONDITION DUMP OUT THE FUEL FROM THE AIR CHAMBER AND BLOW FRESH AIR INTO THE CHAMBER UNTIL ALL SIGNS OF FUEL VAPORS ARE GONE.
4. RESTART YOUR AQUASCOOTER AS NOTED IN STEP #1.
FIRST THING IS TO LOOK FOR FUEL IN THE AIR CHAMBER.
There are 2 hoses inside the fuel side of the tank. One fuel line has a filter on one end and lies on the bottom of the tank to pick up fuel, while the other side connects to a nipple on the inside of the tank above the fuel valve or where, on early AS-400’s, the fuel line connects on the outside of the tank. The other connects to a nipple at the bottom of the tank, inside on carb side, and goes up to the nipple on the inside of the fill necks bottom. As fuel is drawn out it is replaced with air drawn from the front air chamber. If that hose becomes disconnected at one end it allows fuel to flow into the air chamber causing a choked situation. This will not allow your Aquascooter to start. Two things make the hose disconnect from the nipples.
1-The top one can disconnect if pushed down and off when adding fuel.
2-The hoses become weakened by fuel additives, becomes tooooooo soft and slips off the nipples or cracks.
Reconnecting or replacing these hoses without proper tools can be very difficult, suggest it is better left to an Aquascooter service tech. The tank can be removed from the engine body and sent in for this repair.
One other item that can cause this problem is a missing Duck Bill on AS-450 and newer Aquascooters. This DUCK BILL is located just under the fuel fill cap in a cavity on the carb side of the fill neck. Replacement DUCK BILLS can be ordered. It's easy to install.