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+--- Thread: Bike crank but wouldn't start. (/showthread.php?tid=4833)
Bike crank but wouldn't start. - zirconxi_imp - 01-22-2020
Hi all,
3 days back i left my bike park outside in the rain. After the rain stop i rode the bike to fill up some gas and took her for a short 10km ride to dry up. Once home its been parked under roof. Today when i try to fire her up, she give me crank but just wouldn't start. I place my hand over the exhaust and can feel the air pulse. When key turn to on, have the usual fuel pump priming. Could it be bad gasoline or injector clot due to rain water?
RE: Bike crank but wouldn't start. - Buzzard Biker_imp - 01-22-2020
Try popping off the ignition leads on each plug. Make sure they are dry and squirt a little wd40 on them.
RE: Bike crank but wouldn't start. - zirconxi_imp - 01-22-2020
Well, i did further investigation and more question pop up... the bike doesn't have sparks, and no fuel injected as well...the spark plug i pulled are all dry, and when i hookup a sparkplug to the cable and crank it while touching the cylinder head, no spark. or did i do it wrongly?? Any possible solution?
RE: Bike crank but wouldn't start. - Blockhead_imp - 01-22-2020
Have you checked the battery? Weird things seem to happen when they are going bad.
RE: Bike crank but wouldn't start. - GoldOxide_imp - 01-22-2020
Battery?
RE: Bike crank but wouldn't start. - zirconxi_imp - 01-23-2020
But the bike crank... Would a bad battery be able to crank a bike?
RE: Bike crank but wouldn't start. - Lord Popgun - 01-23-2020
A bad battery can crank a bike. But if the voltage is dropping too low the electronics won't work.
If you put a multimeter on the battery, what does it read? Now, what does it read when cranking?
Max will write a dissertation on this.
RE: Bike crank but wouldn't start. - Django - 01-23-2020
Kill Switch?
RE: Bike crank but wouldn't start. - max - 01-23-2020
Hi Popgun, i'm in deep thought at the moment, if the bike cranks at a normal pace the battery is fine, if it is slower to crank there may not be enough energy left to produce a spark.
Zi, do the; cel, hiss and eot lights come on in the top left corner of the indicator panel for a second and then go off again? if they do the ecm is doing it's normal startup routine and the fuses etc are ok.
The coil, injectors and ecm all get their 12v supply from the "engine 12v buss", there are 10 black/white wires connected together and one of them is the supply coming from the engine stop relay, the buss is located under the fuel tank.
Here is a drawing that may help;
![[Image: cd39f888ace261c6213cc8402671454c.jpg]](https://cb1100forum.net/forum/uploads/imp/202001/cd39f888ace261c6213cc8402671454c.jpg)
You would know that there are only two coils for 4 cylinders so only one sparkplug can be tested at one time whilst the other side is still connected to it's sparkplug, as you may know it takes the ecm two full rotations to "discover"which is the correct cylinder to fire up, it has no way of telling which cylinder the crank sensor wants to ignite and that takes a bit of "hit and miss" to work that out initially.
If the ecm cannot detect a signal from the crank sensor it is unable to determine the timing and therefore won't fire or inject fuel.
The crank sensor is on the right hand side of the engine , exits at the top of the cover and you may be able to see it with the timing cover inspection screw removed ( the big aluminium one with the hex nut that can be screwed out ), i would have a look inside and look for moisture.
The crank sensor is a "reluctor" type with a white and a yellow wire, i am guessing the signal is small and sensitive.
Not sure if there is a fault code for this sensor if it fails but you can try to unplug the connector with the white and yellow wires and see if that creates a fault code, i think it is behind the right side cover.
Another test is to remove the spark plugs to make the engine crank easier and see if the tachometer comes off the stop when you crank the engine and reads slow rev's, it gets it's information from the crank sensor through the ecm, so if there is a small deflection on the tacho the sensor would seem ok.
Water in the fuel is possible but very unlikely, the tank filler cap has a good seal and water is unable to get past it.
If you have a spark it may be an idea to spray some carb cleaner or similar combustible mist into the air cleaner intake and see if that fires the engine.
I hope some of the hints may help you to understand what keeps the bike from starting up.
RE: Bike crank but wouldn't start. - pdedse - 01-23-2020
Malaysia / Oregon (winter)...our climates are very different, and theoretically maybe it shouldn't matter, but I've had 2 difficult start ups the the last 2 winters as I've posted [url=http://cb1100forum.com/forum/showthread.php?tid=13697]HERE.
My start-up display seemed to indicate all normal, fuel pump whir was there, bike cranks great but would not turn over. I normally don't touch the throttle upon start-up. But both times when the bike behaved like this, I got the bike to start by opening the throttle about 1/4. Throttle fullly open would not start, just when it was open a little. It turned right over after 2 seconds, sputtered, and then ran smoothly. Each start-up after this was fine. No throttle necessary just like before, zero issues afterwards.
The only two issues in common for these two instances--which happened a year apart from each other--were 1) bike sat for 1 week to 10 days, and 2) cold weather (32-37F).
Maybe try starting bike with throttle 1/4 open to see if that helps.