XL 800 won't start after sitting

[wildfire]

2001 Yamaha XL800 w/65 hours on it, no problems till now.
Never been in salt water & garaged during freezing.
After the ski sits for a couple of weeks it will not start. It turns over, there is spark and the choke is pulled out. If I pull the plugs and throw in gas it starts up and runs fine, it will start back up continually if it doesn't sit too long. I checked the fuels lines they all seem to be in good shape (no cracking) and properly connected and did I say it runs great once it gets started. The local dealer lost their jet ski franchise so I'm stuck with trying to get to the bottom of this myself.
The registration calls it an XA800Z, the decal on the outside is an XL800. There have not been any modifications done to this. I'm thinking fuel pump but can't find the darn thing. It will run 55 WOT for as long as you can hang on to it. So maybe it's not the fuel pump. Any help would be greatly appreciated.

[uncle-buck]

Re: XL 800 won't start after sitting

Your ski uses vacuum/pulse from the crankcase to pump fuel and the pump is attached to the carb. It's not a separate electrical or mechanical pump.

Check the pulse lines first. If OK, check the choke valves and make sure they're closing completely when you pull the choke handle. If OK, check the fuel tank vent check valve. If OK, connect the battery to a battery tender and leave it connected when you're not using the ski. If that doesn't solve your problem, you probably need to rebuild the carbs, making sure pop off pressure is set correctly, and making sure that the needles and seats are in good shape.

[wildfire]

Re: XL 800 won't start after sitting

Thank's for the reply, all the lines and associated connections look good and there is no cracking. I have not checked the needles & how they set however I would certainly not expect to do any carb work with just 60 hours on them. Our last jet ski had about 250 hours on it and the carbs were never touched and to my knowledge the girl that purchased still has not done anything to them 2 years after that. A new battery is on the way which could make a difference in the quantity of vacuum produced on start up. So what's your opinion on a manual primer, I noticed yesterday while at the dealer Honda is putting manual primers back on their atv's. I found that interesting.

[David3aces]

Re: XL 800 won't start after sitting

your ski has an accellerator pump...(I can't spell) that squirts fuel into carbs with throttle use....so pump the throttle alot on startup ....works for me.....early skis didn't have this feature......

[wildfire]

Re: XL 800 won't start after sitting

:) Very Interesting...... This was the first time I attempted to start this sucker since October ( so yes it was sitting for 7 months.) With the choke pulled out I pumped the throttle about 20 times and it started. Too bad the owners manual doesn't tell you about that, I guess with all the warnings and disclaimers they rint there's no room for important operational info. Hey Thanks for the tip!!

If your ever at Lake Powell I owe you a cold one.