HOW TO ROUTE/PURGE FUEL SYSTEM LINES
Listening closly, Open gas cap in case any pressure is in there, then re-tighten. Remove the gas supply line from carb
and put the hose end into a catch bottle. Remove the fuel return gas line from carb nipple and blow a small amount of air chuck pressure into return line. Watch routeing fuel flow easily from
supply in a bottle, IF it routes good, the carb is faulty from a clog or pump diaphram has a hole.
Check pulse tube for clog, it operates the fuel pump with a push-pull or suck-blow as pistons
go up-down in engine case, that is how the mag carb pump actuates route pressure thru the carb, and back into gas tank . A WD-40 straw works good for that. Attach a 2'short fuel line to the tube and if you can blow into the crank-case, its clear of debris.
On dual carb systems, when the mag carb (it gets fuel first) clogs and the PTO carb starves as a result, and that cylinder runs lean, then seizes first. Running lean can cause Glow-plugging and the engine will Rev run-away. Pulling off the lanyard will not help. Asphyxiating by pulling choke and opening throttle may stop engine run-away. Pulling spark wires may injure you and not kill engine as its getting fire from burning piston carbon or red hot spark plug.
Any SeaDoo or other jetski with OEM grey tempo fuel lines will need the entire fuel system rebuilt due to known problems with internal fuel-line deterioration & resin goo clogging up the small internal carborator filters, fuel selector valve and most other fuel system components. Symptoms also include engine bogging at higher speeds (3500 rpm). Continued riding will cause carbonizing & a burned aluminum pistons and engine failure due to lean fuel/air mixtures and high combustion temps. The only solution is to replace ALL the fuel lines with standard automotive NAPA lines, clear race Fuel lines like:
http://fuellines.biz, or equivalent, rebuild the carborators with Genuine Mikuni OEM rebuild kits,new needle & seats, and replacing the fuel selector valve. It is suggested to install a clear glass marine grade inline fuel filter just before the carborators to catch any remaining debris, and do a pre-ride dump of the water separator fuel bowl.
Inspect the fuel separator,filter,square O-ring and gas tank vent TWO one-way check valves, that open at 3-5 lbs psi. One breaths air in from near front compartment latch, One expells under the rub rail, if this one clogs or fails overpressure in tank can open the needle valve(s) and leak fuel into a shut off engine. A hard to start occurs and can wear out a starter prematurly. The fuel bafel's bottom removable cap filter/screen if not cleaned recirculates hardened injection oil mineral sludge Goo/debris into the carbs, over & over until the carb filters fail, then bogging occures.
When the Aluminum carburetor & Aluminum Selector valve goes ungreased, moisture permiates Aluminum Oxide thru the walls into the fuel circulatory of carbs, lines, bafel, selector, and separator system. It is estopped by the bafel bottom screen from re-entering the tank. When these AO molecules mix with injection oil sludge, a stopage usually occures at the carb cover fuel hole as a "liquid steel" clog that can only be removed by an 1/8th inch drill bit.
ALWAYS: before starting the engine, remove the seat and look, touch, and SMELL for gas leaks or gas vapors.
Use 7" quality zip ties. I like Thomas & Betts.
http://www.tnb.com/ps/pubint/index.cgi?a=get_sub&cid=2 --On my raceing engines I prefer catalog # TY232M, a polyamide & SS ty-rap (zip-tie).
http://fastflowfuellines.com/ I just LOVE the CLEAR line.
http://www.sea-doo.net/Specifications/index.asp Red Stripe USCG approved fuelline by Goodyear Rubber Products is the Best (and most costly) for stock ski's in my opionion.
Gas Tank Breather Check Valves
A common cause of a carburetor needle(s) & seat(s) leaking fuel into the cylinders, wetting the spark plugs and causeing a hard start condition when motor is hot. How can gas get past a needle valve other than what I have talked about? One way is if the fuel tank pressure release check valve in the OUT vent line thru rub rail is not functioning. The fuel pressure in the tank overcomes the spring tension on the needle valve and gas is FORCED past it. The valve should open at approx. 3-5lbs. psi.
Liberal use of Grease on Carbs
Grease on all carb threads during re-assembly will make taking them apart again. If after re-assembly if carb fails the leak down test of holding 5 lbs psi on your pop off tester for 5 minutes. Moisture permiation thru the carb bodies can pick up aluminum molecule oxidants and can form mineral deposits internally and clog the small carb orifaces & filter. Use of White Litheum grease or marine grease helps prevent this electrolitic process. Saltwater adds more electrolosis to the minerals causing them to become potasium cementious. Apply grease also to cables & linkages.
ROTARY VALVE OIL LINES
The two small 1/8th inch id X 6 1/2" long oil lines from the Oil Injection Pump to the two Rotary Valve spigot nipples, have a very short lifetime of 3-4 years, then turn brittle, leak, & break, and is a leading cause of engine failure from lubrication deprevation (no lubrication). Changing these oil lines is recommended every two years.
Hope this is useful, Have a Great Summer. Bills86e
