2001 yamaha 115hp 2 stroke wont start

[ferrans]

would not start. tilted motor all the way up and it fired right up.
cleaned filter, replaced old primer bulb, same problem. Good spark. Once started runs fine at higher speed but rough idle.
Sprayed marine carb cleaner on linkage and carb throats and let sit.
Fired up then died and wont start at all now, even tipped up.
doesn't seem to be getting gas to carb.
Today I will check gas coming out of fuel pump and try squirting right into carb.
Has a choke right on front of motor and when you turn key on I can hear something running that I believe is supposed to prime carbs but Im not sure
Any help appreciated, only 1 week of duck season left.

 

[JoLin]

Hit or miss troubleshooting probably won't solve your problem, and spraying carb cleaner into the throats does nothing if they're dirty. How long have you owned the motor? Do you have a shop manual for it? Was it running well just before this problem started, or was its running condition deteriorating? When were the carbs rebuilt last? You say you have 'good spark'? How do you know that- did you use a gap tester on all the plugs to confirm? When you 'cleaned the filter' did you find any dirt or water in it?

Not trying to give you a hard time, but I'm shooting a running issue on a 85 hp right now, and there really aren't any shortcuts. I have the Yamaha repair manual to guide me. I used a digital multimeter (you can get one for $20.) to test resistance on each spark plug, plug cable, all 3 coils, the pulser, the charge coil and the lighting coil. Checked engine compression and finally put a spark gap tester on each plug to confirm a consistent, strong spark. I confirmed no electrical issues or mechanical issues (good compression), so I know that the 'spark' component of the engine is okay. That leaves either fuel (pump/carbs) or air (possibly a vacuum leak) as the likely remaining culprits.

I'm on to the carbs. Removed them yesterday, and today I'll strip them and start the cleaning/rebuild process.

Give a little more background on your problem. A wild-assed guess on my part would be that the carbs need to be rebuilt, but again, that's just a guess.

 

[ferrans]

Was running good but has been hard to start when cold. New plugs 2 weeks ago. Carbs have not been rebuilt since ive owned boat which is 5 years.
I was just leaning toward fuel problem because it would start when I tilted motor all the way up which had fuel flowing down to carbs.
problem started about ten days ago. No dirt or water in fuel filter. I know im shotgunning but was hoping to get through this last weekend of duckhunting beforereally tearing into carb rebuilds and complete elect. Check.
might just miss the weekennd start carb rebuild for a start.
thanks for posting back.
tt

 

[99yam40]

the tilting may mean a bad connection when wiring bends.
Testing compression, spark, timing and fuel pressure/ vacuum is always a good start to see where you need to go while problem is there

 

[Prof Thomas]

the tilting may mean a bad connection when wiring bends.
Testing compression, spark, timing and fuel pressure/ vacuum is always a good start to see where you need to go while problem is there

Here's a good 1, help ! Went to Change gas tanks, motor IMMEDIATLY won't start, unless in neutral with throttle advanced. Dies when put in neutral to shift into gear. Checked fuel lines, Mechanic reccomended replacing fuel pump. replaced both fuel pumps, hi & low pressure. Motor immediately started, ran. Went out twice, went to change tanks on 2nd trip. Immediately won't start again ! If it was bad gas in 2nd tank, it should have started and run for a little bit before the bad gas got to cylinders. Both times changed back to 1st tank, not starting. It will start in neutral with throttle advanced but dies in neutral before I can put it in gear. Fuel is getting too cylinders, fuel rail has pressure, checked hoses, clamps. Put new fuel in 1st tank & sea foam ? Still can't get in neutral to engage. Is this a vacuum hose ?
Is it electrical ?

 

[Prof Thomas]

Here's a good 1, help ! Went to Change gas tanks, motor IMMEDIATLY won't start, unless in neutral with throttle advanced. Dies when put in neutral to shift into gear. Checked fuel lines, Mechanic reccomended replacing fuel pump. replaced both fuel pumps, hi & low pressure. Motor immediately started, ran. Went out twice, went to change tanks on 2nd trip. Immediately won't start again ! If it was bad gas in 2nd tank, it should have started and run for a little bit before the bad gas got to cylinders. Both times changed back to 1st tank, not starting. It will start in neutral with throttle advanced but dies in neutral before I can put it in gear. Fuel is getting too cylinders, fuel rail has pressure, checked hoses, clamps. Put new fuel in 1st tank & sea foam ? Still can't get in neutral to engage. Is this a vacuum hose ?
Is it electrical ?

Sorry, it's a 2006 Yamaha 115 4 stroke. & I also put in new plugs