2003 VMAX200 started right up after sitting for months now won't start

**maineidyl** · 02-16-2017, 08:29 PM

Had my Yamaha under cover for 3 months. Went to start it and it started on the first crank. Decided to run it so took it to local ramp. Started firsts try. While at ramp idling it turns off and would not start again. Tried for about 5 minutes and it tried to start two times for a second or two. Otherwise no indication of even wanting to run. I have no idea where to start on this. The primer bulb was hard but abnormally hard. Like brittle rubber. Is there any where in particular I should start on this beast?
Thanks in advance

Tom

**tunnelmike** · 02-17-2017, 11:13 AM

First thing I would try is changing the bulb , especially if you run ethanol fuel. If the check valve in the bulb isnt working it can restrict fuel flow. If yes on the ethanol fuel I would also drain the tank. My Samurai sat a while and it had this gelatinous green crap come out of the system. It was thick enough to stop fuel flow thru the line. Mike

**tunnelmike** · 02-17-2017, 11:15 AM

If it's a carb motor you can unscrew a bowl drain to check for the presence of fuel and also the condition of the fuel. Mike

**cali kid** · 02-17-2017, 01:30 PM

Assuming it's an HPDI. Listen for the electric fuel pump to cycle,when you key it. Should run for around fifteen seconds.

**berzerko** · 02-17-2017, 01:38 PM

bad cell in battery can also cause start issue.. ECU needs 12.5 volts while turning motor to fire, battery may check out fine but..... ask me how i know

**maineidyl** · 02-17-2017, 02:58 PM

It's fuel injected. Not HPDI.
Tom

**ghost28** · 02-17-2017, 05:20 PM

my bet is the fuel system is varnished up...i would test the fuel pump and then clean out the VST and change all the filters....

**rob@sportsmancenter** · 02-17-2017, 11:26 PM

If OX 66 look at Electric fuel pump, after checking fuses, open up VST assy and soak all components and pump in engine tuner(Mercury power tune) overnight and test pump repetitively with 12v power source and usually The pump will break free and operate . Resemble and test run. If pump operates you should be ok. Also if you hadn't in a while remove the o2 sensor and transfer tube clean and also soak in same cleaner.

**Capt.Insane-o** · 02-17-2017, 11:36 PM

needle is stuck in the vst.

**maineidyl** · 02-19-2017, 03:27 PM

Replaced bulb. Cranked up for 5 seconds then died. Going to get gaskets for vst and clean all that Tuesday. I have spark. It's starving for fuel.

**ghost28** · 02-20-2017, 09:15 AM

Those motors are very finicky when it comes to the fuel system....if all is not dead on they wont run at all or if they do they run like poop....

**maineidyl** · 02-21-2017, 08:21 PM

Ok, so the conclusion. I replaced bulb with a Yamaha fuel bulb. Still no start. Blew through the bulb ->and checked for air leaks in fuel line. Found fuel coming out of water separator on side of motor. Realized that some idiot (me) when replacing the filter only partially tightened ring and then set lock nut. This was right at the end of summer before I put boat away. Tightened the way I should have before and did the blow through test again. No leaks. Pumped bulb and the filter canister filled with still no leaks. Turned over, would not start. Took VST apart, replaced screen. Put back together, pumped bulb. Turned key and boom. Started on a 1/4 turn. Ran on muffs. Shut down about 10 times and started every time. Will water test Thursday. Thanks for help suggestions and ideas. All items replaced were over due and I am stoked that she is running again.