Hey y'all.
I got an 08 Harley Nightster. I really don't want to pay to take it to the shop unless that's the last resort. My bike hasn't been starting for the last three days no matter what i do and I've checked just about everything i can think of to fix it. It was running fine before i turned it off, and then when I went to start it up soon after it would turn over but not start. I've changed the spark plugs, the battery, and the starter relay. All of the fuses are good and it has plenty of gas in the tank. I've pulled the plugs thinking i just flooded the engine but still no dice. I've checked to see if the spark plugs are sparking when the engine cranks and they are, so then I looked into the fuel system. The fuel pump works and I tried cranking the bike with the fuel injectors isolated from the vtwin. They are both spraying fine. When I spray starter fluid into the air intake it'll nearly start up which makes me think it's something else with the fuel system but idk what. It's not bad gas either because thats the first thing I tried. Does anyone else have any ideas before I take this thing to the shop? Much appreciated!

 

Sounds like you need to do a fuel pressure test

 

starting fluid can cause serious damage.
even if the pressure was low, if the injectors are putting out some fuel, the engine would at least fire up although maybe not sustain rpm. the fact that it will sputter on (uuugh) starting fluid says a lot.
there are a couple of good tools to have, inline spark tester and noids to test the system. just because the plug fire out the cyl does not mean it will in the head, aka the inline test. the noid will tell if the injectors are receiving pulses.
sound like you have essentials so now test to see if you have compression. if you get feedback from an intake valve, it will kill the intake track, although it should at least pop every now and then. are any codes thrown?? a good issue for no start is the crank position sensor, if the timing is skewed then it will not tell the correct info to the ecm.

 

If pressure is too low it will not sputter. This doesn’t sound like compression because it was instantaneous and fires with fluid. This is in the the fuel system whether it be a fuse/connector, bad pump, loss of pressure, problem at filter. The fact that if fires appears that it’s seeing crank signal. Listen for fuel pump coming on at keyup. But I would still say you need to do a fuel pressure test.

 

if the injectors are even dribbling, the vapors will eventually make it to the cyls and it will ignite. be like spritizing fuel into the TB. an engine will run on low fuel pressure but will not make power nor rpm under load, idle?? no load??? it should run. this happens all the time and does not mean the pump is the issue, could be inlet or discharge screen/filter and the regulator.
although not probable, valves can hang, just saying that an intake issue will pressurize the manifold, aka, low vac signal so fuel mix will not flow. the issue with compression is if it is low, hard or no start.
if the cps is skewed, it can squirt all the fuel in the world and spark till it lights up the evening skies, it will not run.
will ether pop an engine over and not gasoline, sure, TWO diff animals. ether is so volatile it can pre-ignite and raise compression so high it will lock the engine up and can cause damage.

 

Check for hose leaks inside the tank. Also try reconnecting the fuel line from the tank if it is a quick connect style.