Fuel problem - bike won't start

[5ehsx]

Hi, I'm new for this forum, riding my #1700 since more than 10 years.
I have a quite weird problem: I havn't been riding for a couple of years, but when I finally did, my X started at the first try! I have been riding for 2 days and several problem-free miles.
It happened I had to stop the bike for about one month as the switch bracket went broken. When I finally mounted it back the engine could not start.
Sparks and fuel pump are ok and it seems that if I press the test port on the intake (that like a tire valve) the gasoline leaks out but the engine starts, when I release the valve so the leak stops, the engine stop running...
It seems to me like a full nonsense, someone have some advice??
Thanks for all help!!

[wytfut]

I guess I need a couple questions answered...
when 1700 sat for "couple of years", was it stored dry, as in no fuel? And if there was fuel in tank, hopefully it wasn't ethanol?

I've seen/heard many times, X's stored with ethanol.... the ethanol will/does eat our OEM fuel tank liners, and sends that gunk down the fuel path to the injectors.

just guessing without more information, your injectors finally plugged up with your infrequent recent riding. With the shrader valve plunger pushed its releasing pressure, off of gunk blocking injectors. You release plunger, and they get full pressure which will block gunk at injectors. Just a guess so far.

Everyone out there as a reminder....  I've said it many times in the past as past monitor of this site, if you store for any extended time the best is to completely empty the tank. Second choice is to make sure what gas in the tank is not ethanol blended, and if it is not blended, make sure its full to the top, so as not to attract moisture.

Gasoline and motor oils are nothing like they were 20 years ago. I've heard it many times, shelf life of modern gasoline is around 60 days plus/minus. Ethanol in my opinion is even less. Most modern hi rated motoroils made today far surpass the oils of yesterday.

[Donkey Hotey]

From the registry entry, it looks like you are in Italy? You probably don't want to ship that fuel pump around the world to be worked on. You probably also don't want to pay for too much shipping for parts coming from the US.


To be clear: the fuel pump should have 2.5-3.0 Bar of pressure to run properly. I would expect that valve to spray fuel, not just leak some. I don't have any plumbing to allow me to measure pressure at that port but, you could connect a gauge directly to the output of the pump at the tank. It should build and hold pressure for the engine to run properly.


Are you comfortable taking apart the fuel pump assembly and replacing all the o-rings and hoses? The o-rings do fail regularly (every 3-4 years for me). Modern fuel is very hard on all of those parts. Atlantic E-H should know what you need and be able to put a kit together in one shipment.

[5ehsx]

Thank you Greg and Bruce!
It's right, I'm in Italy and for some years ago I bought some stuff from Marty / Atlantic, she was very kind and helpful.

I'm trying and clean the injectors, so I let you kow soon.

Enjoy the week end!

[5ehsx]

Both injectors, fuel pump and fuel hose were extremely clean, I brushed the oxigen sensor too; I'm afraid I have to think about electrical problems.
For some days ago it happened I accidentally touched the frame with both the poles of the battery for half a second, I don't know if something got bad even if all fuses were ok.
Thanks again for any advice!

[Donkey Hotey]

Clean is good when it comes to the fuel components but, the most common failure for the fuel pump could still be bad: the o-rings. There are two o-rings on the fuel pump nipple (where it goes into the plastic regulator body). There are two more o-rings on the metal pressure regulator, where it goes into the plastic housing. If any of those have dried out and split, it won't build pressure.

I don't know how much ethanol you have in your fuel over there. Here in the United States, we have about 10% ethanol. It destroys those o-rings every 3-5 years for me.



Spray some carburetor cleaner, starter fluid or even some raw gasoline into the throttle body, open the throttle and try to start it. If it starts for a second, you have a fuel problem.

[5ehsx]

hi again, I've been off for a while also trying to find (read guess) a solution.
Cleaned injectors, brushed oxigen sensor and new fuel pump with new regulatore gave no better results.

Finally I changed the IAC valve and the engine started!

Stay good out there!

[Donkey Hotey]

That's excellent news. I wondered what happened to your bike. I must wonder what happened to that Idle Air Control motor for it to fail. I believe Bruce has some experience with failed ones but, I also wondered about those.

Was your old one covered in oil? Are you using the original air cleaner? Or do you have the oil breather routed to the air filter? I'm wondering if it got gummed up or something.

[5ehsx]

So sorry for this delay but I'm back to the beginning: my bike refuses to start again, so I have to sum that the IAC had nothing to do with my troubles.
I asked EH Atlantic so I let you know as soon as I have some news.

[Donkey Hotey]

Let's start back at basics. The engine needs fuel and spark to run.

Can you buy a can of starting fluid at a car parts store? Remove the air cleaner, open the throttle and spray that into the engine. With the throttle open, try to start it.

• If it starts, then dies soon after, the ignition and everything related is working. It has a fuel delivery problem.
• If it does not start, something is wrong with getting spark to the engine.

Engine starts, runs for a second or two, then dies
This is usually due to a fuel supply issue. The absolutely most common thing on our bikes is an internal leak on the pump assembly in the fuel tank. This past weekend I almost did not make it home from a short ride because of one of these type failures. Pressing the Schraeder valve on the injector manifold is a basic test to see if you have pressure. It could still be pumping and not have enough pressure to run. Assembling a test gauge to check the pump is cheap and easy.

For anyone here in the United States, this is less than $20 at Home Depot. Ace Hardware or similar should have the parts. This is a game changer because you finally see exactly what the pump is doing. I've used mine to diagnose and repair one bike three days ago and tested another yesterday before taking it out on a ride. The second bike was okay but, something is leaking inside and will need attention soon.

https://www.homedepot.com/p/Everbilt-100-PSI-Pressure-Gauge-with-1-4-in-Lower-Connection-EBM1002-4L/205617969
https://www.homedepot.com/p/Everbilt-1-4-in-Barb-x-1-4-in-FIP-Brass-Adapter-Fitting-800209/300096277

I'm providing the links so you know what to look for in Italy. Those parts and a piece of 7mm fuel hose is all you need to hook up to the pump outlet port and see what's really going on. It should build pressure to 3.8 Bar (50 PSI) and when the pump shuts off, it should hold at least 2 bar (30 PSI) for 10-15 seconds. Ideally it's supposed to hold pressure for longer but, I'm being realistic. If the system can get to full pressure when it's running, that's what you're looking for.

Engine does not start
If the engine did not start with the starting fluid sprayed into the engine, the engine is not getting spark when it should be. By spraying the fluid in you took the place of the fuel side of the engine. Air gets in because the throttle is open. What's missing is something to ignite the mixture.

• Because you have two ignition coils,  it is safe to assume both did not fail at the same time.
• If the engine cranks and the fuel pump runs, that proves the computer and all the other components are getting voltage. This eliminates fuses and much of the wiring as culprits.
• The next test would be to again check for spark. Remove one of the coils and the spark plug. Make sure you're getting spark.

If you are not getting spark, my money would be on a bad crankshaft position sensor. When that sensor dies, it has no idea when to fire the ignition or injectors.
I bought 1989, not running. It was the crank sensor. I have been through this once.

Same bike, some time later: the speedometer sensor failed intermittently. It would work until an hour into a ride and then the speedometer would stop working. If you have an intermittent condition where the engine dies for no reason and won't restart, it could also be the crank sensor. The crank and road speed sensor are not the same but, similar enough that they can have intermittent as well as total failures.

[bobbybhb]

Some good information Greg.
If the crankshaft position sensor is faulty then the tachometer should be at zero while cranking it over.

[Donkey Hotey]

I used to believe that and even probably posted it elsewhere. For whatever reason, the tach doesn't seem to budge on these bikes until the engine actually starts. I just verified that.

[5ehsx]

Thank you for answering, as the engine starts when the test port is open I assume the sparks are ok. I'm actually waiting for a new (used) crankshaft sensor and a  new temp sensor (in case it gives wrong temp and the mixture is too rich or too poor...).
Just one more thing: let's forget for a while that the engine starts if I open the test port. I had a fuel pump that gave near zero pressure at the pressure gauge even if it sounds normally when the ignition switch is set to "on" position.
I already changed that fuel pump with a new one, but even here the pressure is zero. My question now is: is there some component BEFORE the fuel pump that can give wrong information so the pressure is so bad when just switching on the ignition switch, but in some weird way "wake up" when I open the test port? If the pressure is zero all the time, the engine can't reach 3-4000 rpm just because I open the test port...
Thanks for helping, you can understand I feel a bit lost right now...but still far from giving up.

[Donkey Hotey]

...as the engine starts when the test port is open I assume the sparks are ok.

Going back and reading your first post about this, I see that you said that. Having the port open is a coincidence. You said you installed a new fuel pump. I assume you mean just the motor portion of the fuel pump and not the whole assembly.


If any of these O-rings are leaking, the pump will not maintain pressure. Have you replaced all of them? There are two on the regulator (yellow circle) and one or two on the fuel pump outlet (green circle).


Also: carefully inspect or replace the plastic fuel transfer hose. They are getting old and they do leak. Also inspect the 90 degree elbow coming out of the plastic regulator body. Is the black regulator body cracked at that spot? They can crack and if that happens, they leak badly.


Any of these failures could cause the system to not maintain enough pressure. There are no sensors in the fuel supply system. The pump makes more pressure than is needed, the regulator releases the pressure the system can't use and maintains 3.8 Bar of pressure. After the pump assembly, you have nothing but the rubber hose going to the injectors and the small metal manifold sending fuel to both injectors. The valve you were pressing is just a test port to measure the pressure with a gauge. There is nothing else in there. If the pump is running (you can hear it) it's working. If you have a gauge and it says zero, something in that assembly is leaking inside the tank.

[Donkey Hotey]

If you need those O rings, you should be able to buy them locally. These are the industry standard sizes for each of them. You should make sure to buy Viton and not Buna-n or Nitrile O-rings. They won't last very long in the gasoline.

 

-229	Pump Assembly Seal
-109	Regulator Small
-118	Regulator Large
-011	Fuel Pump Outlet (2)