Bike won't fire

[Davidmo3]

Hi guys, yesterday had to tighten the carb screw because it wasn't idling right, after tightening it was running great, went back to it and now it won't fire, the spark plugs are working but they was covered in some type of black oil, any suggestions?

[Northern Biker]

What bike is it, and what carb screw did you tighten?

[Davidmo3]

Hi mate it's a suzuki intruder 125, I tightened the carb idle screw as it kept cutting out if I wasn't pulling the throttle, but it was running fine but now it just won't fire

[Mississippi Bullfrog]

Sounds like fouled plugs due to the previously over-rich mix. Try cleaning the plugs, check the gap whilst you're at it.

[Davidmo3]

Hi mate had cleaned the plugs and they was sparking fine, is there any chance it could be flooded

[Mississippi Bullfrog]

If you've left it a while any fuel in the cylinders should have evaporated off by now. If you want to make sure take the plugs out, put a rag over the holes, turn it over briefly which will eject anything left in there. Refit the plugs and see what happens.

A flooded engine can usually be fired by opening the throttle fully to allow more air into the cylinders.

[Davidmo3]

If you've left it a while any fuel in the cylinders should have evaporated off by now. If you want to make sure take the plugs out, put a rag over the holes, turn it over briefly which will eject anything left in there. Refit the plugs and see what happens.

A flooded engine can usually be fired by opening the throttle fully to allow more air into the cylinders.

 

Hi mate the only thing I can think is when I was last on it I hit the kill switch when getting off the bike, any chance this could of done anything? I took the spark plugs out and they had like a dark liquid on them

[TimR]

Are you 100% sure it was the idle screw you turned and not the mixture screw ?

If that is all you have done before it stopped working

I would if you could remember how much and which way you turned that screw restore it to those previous settings and see if it fires

Second picture down locates idle screw

https://www.manualslib.com/manual/804522/Suzuki-Vl125.html?page=22

You have turned the kill switch back on ?

[rennie]

exactly what I was going to say!

[Davidmo3]

Are you 100% sure it was the idle screw you turned and not the mixture screw ?

If that is all you have done before it stopped working

I would if you could remember how much and which way you turned that screw restore it to those previous settings and see if it fires

Second picture down locates idle screw

https://www.manualslib.com/manual/804522/Suzuki-Vl125.html?page=22

You have turned the kill switch back on ?

 

Yes it was the mixture screw because it was running to rich but then it started running great , turned it off went to start it and it won't fire

[TimR]

Well reading from your posts you have over richened the mixture .

With mixture screws you make minimal adjustments ie 1/8th of a turn

If you are making the mixture richer you may need to also raise the idle revs slightly and vice versa if you make it lean

See if you can get the screws back to their standard settings ( listed in manual)

To get it running to normal running temperaturr and then fine tune if necessary

Be gentle with tuning screws and dont force them when they get to the end of their travel

Make sure your air filter is clean and the choke operation works as it should before adjusting anything

To adjust the idle speed use the idle screw not the mixture screw

[Davidmo3]

Well reading from your posts you have over richened the mixture .

With mixture screws you make minimal adjustments ie 1/8th of a turn

If you are making the mixture richer you may need to also raise the idle revs slightly and vice versa if you make it lean

See if you can get the screws back to their standard settings ( listed in manual)

To get it running to normal running temperaturr and then fine tune if necessary

Be gentle with tuning screws and dont force them when they get to the end of their travel

Make sure your air filter is clean and the choke operation works as it should before adjusting anything

To adjust the idle speed use the idle screw not the mixture screw

 

Hello mate thank you for all your advice, I've gone through the manual and can't find the right adjustments to what the screws are meant to be set as, I have taken the spark plugs out and left them out over night just invade the engine has flooded and got new plugs and also put the battery on charge

[TimR]

Service manual

https://www.manualslib.com/manual/804522/Suzuki-Vl125.html

Page 112 and onwards for fueling details

https://www.manualslib.com/manual/804522/Suzuki-Vl125.html?page=112#manual

Depending on which carb version you have screw turns are listed

[Davidmo3]

Service manual

https://www.manualslib.com/manual/804522/Suzuki-Vl125.html

Page 112 and onwards for fueling details

https://www.manualslib.com/manual/804522/Suzuki-Vl125.html?page=112#manual

Depending on which carb version you have screw turns are listed

 

Got it going now, thank you for your time and help

[rennie]

So what was it then?

[Davidmo3]

So what was it then?

 

i changed the spark plug and charged the battery and it still wouldn't turn, but just before i remembered i connected a new break light, i disconnected the light and it fired straight away

[Davidmo3]

Are you 100% sure it was the idle screw you turned and not the mixture screw ?

If that is all you have done before it stopped working

I would if you could remember how much and which way you turned that screw restore it to those previous settings and see if it fires

Second picture down locates idle screw

https://www.manualslib.com/manual/804522/Suzuki-Vl125.html?page=22

You have turned the kill switch back on ?

 

Hello mate I have adjusted the screw to the manual, but now I am getting orange flames when letting go of the throttle, any advice?

[Westbeef]

Are you 100% sure it was the idle screw you turned and not the mixture screw ?

If that is all you have done before it stopped working

I would if you could remember how much and which way you turned that screw restore it to those previous settings and see if it fires

Second picture down locates idle screw

https://www.manualslib.com/manual/804522/Suzuki-Vl125.html?page=22

You have turned the kill switch back on ?

 

Hello mate I have adjusted the screw to the manual, but now I am getting orange flames when letting go of the throttle, any advice?

 

Turn the screw the other way, see if the flames stop

[TimR]

Did you screw the mixture screw all the way in till it stops ( lightly ) hopefully counting the turns

And then turn the screw out making sure you have adjusted it based on which carb you have .

[Davidmo3]

Did you screw the mixture screw all the way in till it stops ( lightly ) hopefully counting the turns

And then turn the screw out making sure you have adjusted it based on which carb you have .

 

Yes I done this

[Davidmo3]

Did you screw the mixture screw all the way in till it stops ( lightly ) hopefully counting the turns

And then turn the screw out making sure you have adjusted it based on which carb you have .

 

Not doing the flames atm but this is what it's sounding like then cuts out https://youtu.be/Q8g5bzmIF-g

[TimR]

When you changed the plug did you use a specified type for the bike ?

If the brake light you installed had stopped the bike firing am wondering if its caused the coil to short out/ become weak sparked

If its running too rich

Turn the mixture screw 1/8th turn in to lean it out a bit

Try it see if any difference

If not try another 1/8th

Do this 4 times only ( so technically 1/2 turn from its specified setting)

If the screw had been turned in too hard it could have damaged the seat or the needle which would result in an incorrect setting mixture

Video doesn't work