Fuel-Carb questions for '93 VXR650

[pitguy3]

Should you be able to see fuel in the filter? I have replaced the filter and it's empty. I can siphon fuel into the filter but it appears that the carb is not drawing fuel into it. It (filter) will eventually empty from the siphon, but will not refill while attempting to crank. The ski will crank and run for a few seconds while spraying carb cleaner in the intake but not on straight fuel. The carb was just rebuilt by a reputable shop. Help please!! I REALLY want to get this thing in the water. No fun sitting on it in the basement...:emoticonr

[YZrider]

Re: Fuel-Carb questions for '93 VXR650

Filter should be almost full ,check for obstruction in fuel supply and fuel return lines, check that pump operates corectlt and pulser line is properly connected. Check for obstruction in pet-cock valve.

[pitguy3]

Re: Fuel-Carb questions for '93 VXR650

Pet cock valve works. I have not replaced the fuel lines except for thr reserve line which was cut when I got it. Is there anything in the crank casr that would not allow a vacuum to form and not pull the fuel?

[YZrider]

Re: Fuel-Carb questions for '93 VXR650

Fuel is "pumped" via positive/negative pulses from crankcase line to fuel pump body,fuel pump has diaphragm and mylar valves in body of pump which "draw" fuel from tank and return un-used fuel back to tank.

[pitguy3]

Re: Fuel-Carb questions for '93 VXR650

I just hope I didn't screw it up when I tried to run it hooked up to the hose. I turned the water on, then attempted to crank it. I never turned the water off and there was water running out of the exhaust. Should I purchase another carb rebuild kit and do it over or just open it up and dry it out?

[yamahawaverunner56]

Re: Fuel-Carb questions for '93 VXR650

before you buy any more parts i wiould find out why this is happening

[YZrider]

Re: Fuel-Carb questions for '93 VXR650

Engine will liquid lock if water left on too long without engine running. If so immediately remove spark plugs ,pump water out by cranking the engine and untill water is removed, then get engine running ASAP and run long enough to "dry-out" engine. Remember to turn water on after start & off before shutdown!

[pitguy3]

Re: Fuel-Carb questions for '93 VXR650

Yeah I agree, that's why I'm glad I found this forum. I have never owned one of these before so I am CLUELESS when it comes to the way this thing ticks... Thanks for the advise though! I only gave $150 for it so it's not a money pit... yet..:emoticont

(This was directed to yamahawaverunner56 vbmenu_register("postmenu_100884", true); )

YZRider, I wish I could crank it to "Dry it out" but I can't. Should I remove the plugs tonight and let it "Air Dry" and try again tomorrow?

[YZrider]

Re: Fuel-Carb questions for '93 VXR650

Well you are $ ahead of the game already anyway then.

[YZrider]

Re: Fuel-Carb questions for '93 VXR650

Get your air compressor and blow the cylinders sometimes you can get the engine spinning with air pressure down the sparkplug holes. It will NOT air dry as it is also in the crankcase and MUST be removed NOW or corrosion damage will result."JUST DO IT"

[YZrider]

Re: Fuel-Carb questions for '93 VXR650

I dont mean start it but to spin the engine with the starter with the spark plugs removed,when it is spinning it will begin to pump the water out,Good luck.:emoticont

[pitguy3]

Re: Fuel-Carb questions for '93 VXR650

Tech Support, What do you think about this problem?:emoticonn

[Technical Support]

Re: Fuel-Carb questions for '93 VXR650

OK first of all let's deal with the immediate danger - water in the engine! Have you taken the spark plugs out and cranked it over to see if you actually have water in the engine? If not do it NOW! If you do have water in there, you are in big trouble, since you have a fuel problem too and can't star the engine. Without being able to start the engine, there is no way for you to save it - time to pull it out of the ski and either replace it or completely rebuild it yourself.


If you do not have water in there, then we can takle the fuel problem. Let us know where with the water situation you are and we'll go from there.

[pitguy3]

Re: Fuel-Carb questions for '93 VXR650

I pulled the plugs last night and did NOT have water in the engine. (Thank goodness)

[Technical Support]

Re: Fuel-Carb questions for '93 VXR650

OK good. Now what you are describing is the carb fuel pumps sucking the fuel, but not returning pressure. Most likely you need to get rebuild kits and rebuild all the carbs. A good indicator of this is to pull the return line off the carb and blow through it - if you see nothing or a short tricke of fuel coming out the carb rather than a pressurized stream, time to rebuild. If that looks good, then blow throught he return line again and put your thumbs over botht he line and the carb fitting to make sure your tank vent valve is not stuck open - you should not hear and air escaping. If you do, find the leak and replace whatever you need to.


The other cause may be a clogged petcock. I know you said 'it's fine' but what exactly did you do to test it? You can do the pressure test in both ON and RES to make sure they both flow well and equally.