Getting one click from Start relay and nothing else

I have a Gilera runner vx 125, rid it to work the other morning and was fine as a went to leave I went to start the bike like normal only to get a clicking noise from the starter relay and that's it, I know the clicks from the relay as iv unplugged it and when I did I had no click, battery is reading 12.50v so battery is ok, I Also notice when I push the starter button the head lights go dim then return to full brightness when starter button is released. Please help guys, be told it's battery but it's not, order a new starter motor thinking maybe it's that's as I tryed the old trick of hitting it with a hammer but no luck.. Need help as its bugging me like mad what it could be !

 

check the earth connection off the starter motor bolt.
put power direct to the starter positive pole, if it turns over its not the starter motor.

 

Where will I find the postive pole? Thanks for help

 

Just tryed what you said, still wouldn't turn over does this mean it's definitely the starter motor that's failed? Thank for help

 

could still be the earth.
Take the starter off, put the body of it to the negative (-) of a car battery, and a piece of wire from the positive pole to the positive of the battery.
If it still wont turn its the starter thats shot, if it does turn its the relay or the earthing.

 

the engine earth can be a fickle bitch on those, its on one of the front transmission bolts, behind the cooling duct. take it off, clean it up with a bit of sandpaper and try again.
i had BIG problems with this on my VX, there was several causes.
the first was the earth,
then second time was bad contact between the relay and starter motor, the terminals where the relay plugs in got wet and rusty.
third time was the relay stopped working as water got in there.
try these things then i would look at your start motor.
if it helps, an early leader engine has kick start, so if you get the side casing off one, you will have a kick start....

 

Knackered battery or jammed starter motor would be my guess. Batteries live a hard life on scooters, so I would change the battery if it's more than 2-3 years old and replacements don't break the bank. Once you know that you have a good battery, whip the starter motor off and check that it still turns over, the contacts can get corroded and worn with age. I had to strip, clean and rebuild the starters on my TKR and my son's (now my) Honda Varadero.

 

Thanks for your help guys, got new starter motor coming tomorrow, going to just do everything clean earths and so on, relay is 2 weeks old as it fail on me, battery is about 2months old but definitely got charge because I put a Volt meter on it, just strange how lights dimmer when trying to start witch tells me it's a brake in the circuit some where?? Checked all fuses both front panel and under seat.. And can you put a kick start on a 4t can't say iv ever seen one with a kick start on it, really debating wether to just rewire the hole loom but can I be dealing with it lol

 

check your voltage when you press the start button, it should keep reading over 12v

 

Right people brand new start motor on the bike and still no joy, iv tryed putting a straight positive to the starter and no joy tryed earthing for battery to starter motor no joy... Clean both engine mount and frame mount earth.. Still buzzing noise from relay, really pissing me and my wallet off now!! What else could it be.. Spark maybe? The coil ?

 

By-pass the relay and try the jump leads on the starter motor +ve and frame earth. Does the motor turn over now? I am wondering if the starter bendix has jammed. Most scooters have an intermediate gear between the starter motor and the crank and this gear has a bendix that uncoils when the starter is operated, engaging the gear.

 

Yeah I forgot about that.. But surely I'd get some thing from the engine/starter trying to turn over?

 

have you tried a new relay? and chacked the connection at the relay? a bit of fuzz can cause these problems..

 

Right gents iv took transmission cover off the find that I cannot turn the varitor by hand.. Engine is jammed, what could this be? I plan on stripping engine but what's your thoughts? Piston rings broke and jammed up in barrel? Crank shaft snapped or something? I'm getting less than a inch turn back and forth, to the extent of that I didn't even have to jammed varitor to undo the nut..

 

Could be a broken ring jammed in one of the ports, it could equally be a heat seizure. Take the plug out, squirt some WD-40 down the plug hole and leave it for an hour or two. If the piston is heat seized, it may release it enough to get it moving to disassemble it and see what's wrong.

If that doesn't work, then you may need to get brutal and remove the head, lift the barrel up slightly on the studs, wedge some wood under it to absorb some of the shock and protect the castings, block the crankcase if you can with some rags (to stop metal falling into the engine as the piston releases) and try to gently hammer the piston downwards with a wooden drift.

 

Or a valve could have dropped, broke timing chain/tensioner, seized cam.
Could be any number of things, only one thing to do............whip it out, stick it on the bench, strip the bugger.
Then clean it, paint it, and have a beautiful looking engine to put back into the frame.

 

^^^ What he said ^^^

 

cam chain maybe gone? you need to take the valve cover off and see whats going on under there

 

I wasn't sure if his bike was a 2T or a 4T, so I provided advice based on a 2-stroke. We've covered both types between us anyway.

 

Cheers guys.. Iv stripped head and barrel off, it's a 4t, valves all good piston rings and barrel all good. As I try to turn it the piston won't come up? Got about 1/4 inch movement, spary wd40 to try ease it but not joy, going to have to split the engine but what could it be? Barings, snapped cam? Only ever really worked on 2t and never had to dig this deep got a Haynes manual but that's just shit really haha..