bike wont start gilera 125.help please :)

hello everyone, basically i recently went back to standard as in pipe and top end just rebuilt the engine, just been trying to start it, but wont start , i checked im not geting no fuel to the carb, and i was told to try puting petrol into the carb so i did and still no start even tryed easy start and was a no go, and also when i take of the tube from the engine just under the carb to suck it to see if petrol comes out the petrol line it seems impossible to suck can anyone help please??

 

thanks you've all been so helpful , this forum is clearly very helpful

 

Are you sure that you've not got the vacuum and fuel pipes switched over? The vacuum line from the engine manifold should go to the side of the tap and the fuel pipe comes out from the bottom of the tap. If you suck on the vacuum line then this should open the tap and fuel should flow from the pipe.

 

yeah the vacuum pipe is the one under the manifold right? when i suck on it, it seems impossible to suck.

 

There is your problem...alcohol

 

There is your problem...alcohol....?? strange

 

@SPRunnerSP

You have to be patient with us, we don't sit here waiting for problems to appear then all jump in with our diagnosis and knowledge, we also have things to do, like our own full time jobs and projects.
We are a helpful lot, and if possible one of us might be able to come over and have a look if we can't get you to put your finger on the problem. It all depends a lot on how you describe the problem to us, we need information in detail, about what happened to cause you to rebuild the lump, what you had on before etc etc.

Now then, to your problem; you say you are not getting fuel to the carb, merlin said try the vac tap, try this to confirm the tap is working properly.
Take both the pipes off the tap, leave them connected to their parts on the engine, and get two other pieces. Connect each one to the petrol outlet side of the tap and vac side of the tap, suck on the vac one and fuel should flow freely out the other. If it does flow, then the tap is fine and the carb needs looking at.

Also, your bike has the little header tank on top of the main tank doesn't it?

 

I have a gilera 125 , had it rebuilt by a well known tuner but ever since its been breaking. so i took off the top end and pipe and put my standard pipe and 125 top end back on. still have the lighten flywheel and new crank. and when i suck on the vac pipe it seems impossible to suck any air out of the thing lol and yes it had a little reserve tank on
top of the main

 

Right, thats what i thought.
There is a trick.
You have an airlock between the pump and the carb and there is one way to get rid of it.
Take the fuel pipe off the carb and put it into a clean container. Leave the other end attached to the vac tap.
Leave the vac pipe attached to the carb and tap.
Get a length of CLEAR fuel hose, attach it to the carb, then you need to fill it with petrol.
Start the bike.
Don't rev it, just let it tick over normally.
You need to watch both the fuel level in the clear pipe and the fuel coming out into the container.
There will be bubbles coming out the pipe into the container, this is the pump pushing the air out the system.
The level in the clear pipe will drop quite quickly, dont let it completely run out or you will have to start again.
When the bubbles have stopped coming out the pipe into the container, check the little tank, it should be full or near enough full.
Then re-attach the fuel pipe to the carb and it should start normally.
This is the only way to get rid of the air lock in the fuel system.
The engine has to run to push the air out, cranking alone wont do it, and by doing the above it shifts it.

 

i didnt think gileras could get air lock in fuel tank cos they dont need bleeding... and never heard that ever before in my life

 

Wanna bet?
Runners and DNA's are the worst for it.
The air lock isn't in the tank, it's in the pump. It cannot spin enough, under cranking vacuum alone, to create enough pressure to push the air out.
Thats why you never run the tank dry. Creates major problems like yours that has people chasing the fuel system.

 

ok thanks, well you say use CLEAR fuel hose, attach it to the carb, then you need to fill it with petrol. how would i fill a little tube with petrol lol sorry to be such a noob steve

 

some people use a 50ml stringe if they have one, others manage to find other pipe that fits around the fuel pipe so you have a bigger hole, me personally, i bought the big syringe off fleabay, but anything you can find to use. Or, because its clear pipe, use the syphon technique, suck it up the pipe, stick your finger over the end to hold it in the pipe then put it on the carb.

 

ok thanks steve il try that tomorrow and let ya know how it goes

 

so just tryed to feed the carb some petrol, and nothing, so ive took off the spark plug and tryed kicking a few times and not getting a spark at all, tryed 2 other spark plugs and same thing no spark at all, all my electrics seem to be working, headlights , side lights rear elec water pump alarm etc checked the engine is grounded to the frame all wires are connected... any suggestions?

 

just did a compression test also and it was 100 psi so far as i know the top end is all good

 

Stator. Or cdi. Or pick-up. Or flywheel.
Standard Cdi or malossi bypass?

 

ohh no so where would i start then? and i have a standard cdi

 

how do you go about testing all that.... and sorry to sound stupid but what is the pick up?

 

Sounds like the CDI is fried. Does the bike have an immobiliser fitted in the CDI?