Major help needed ASAP....

[jnc81111]

Hello everybody, I'm Josh holder and new to the forum style so bear with me. I have a 2000 triton tr20 w/ a 2004 Yamaha Vmax 3.1 L 200 HP and having some problems. I went fishing today and stopped to fish. When I went to leave the motor would not crank. Just turn over as if the kill switch was unhooked. I checked over everything So I trolled back to truck. Once I got home I Hooked the muffs up and it fired right up as if nothing was wrong. So I took it back down to the water and ran it for about half an hour with no problem. I stopped at another spot and fished for about an hour, went to leave and the same thing happened again. Spin and spin but won't even hit. Had to get towed back to truck. When I got her on trailer it cranked right up! Ain't got a clue somebody please give some insight. I replaced all three LP, put a brand new prime pump bubble and still screwed up. Please help

 

[turkey killer]

have you checked the fuel pump, changed fuel filter, and could be something on the pick up in your fuel tank just a few easy checks it may be something as well going on with the injectors or a electrical problem like the coil

 

[Jmax]

First thing to check are you battery connections. If they are loose it could be bouncing and not hitting consistently. Sounds like something is not hooked up tightly. It would cause the hit and miss program you are having.

 

[beetlespin]

Common Yamaha problem. Check TPS ( throttle position sensor)

 

[silvertalon]

Make sure that when the problem occurs, when you turn the key to on (not crank), that you can hear the fuel pump running. It should run for a few sec then quit. (if its an EFI). If carb, you wont have an Electric fuel pump. I think 'pro max', is carbureted. 1 st, check the harness plug, cannon plug under the hood and all ground wires. Of course the battery nuts too. Sounds like an intermittant spark problem. solid state like the CD module (brain box). Yamaha my also have a shift interuper switch. I'd have to look into that. I had the same problem with my 225 optimax. It was the PCM (ECM). - brain box. Expensive stuff there!

 

[99tr19]

I have a Merc and it would turn over and not start my issue was cam position sensor. Don't know if Yamaha has that but if it does something to explore. Mine was bad connection.

 

[Mr.Finesse]

this sounds like something as simple as a failed check valve in the fuel line, are you re-priming your fuel line after you sit and fish? Are you re-priming when you're trying to figure out what is wrong with the motor(at home on the muffs, at the dock)? If there is a failed check valve in the fuel line, the fuel will drain out of the line and therefore no fuel getting to the carbs. This is a common problem with carburetor engines.