Anybody any good with Carbs ??? The story so far..... Bought a 54 plate Suzuki GN125 as a bit of a winter restoration project. It wasn't running, just clicked once when pressed ignition. I fully charged the battery and it tried to start up, but sounded starved of fuel. I filled up tank, checked plug, dropped some fuel down plug and it attempted to fire up. Trned fuel tap on, and continued to attempt to start up with no joy. Assumed it was the carb as it had been stood for 12 months. I took off carb (what a nightmare....) (Pic attached), and removed the lower resevoir to see if clogged up. It wasn't so I placed it back on carb and after 1 our of fiddling, I got carb back on. I turned on the fuel tap to attempt to start it, and now fuel pisses out of the overflow pipe ! I'm guessing it has something to do with the floats in the carb but am now stuck !! Any advice welcomed......
im thinking when you took the bowl off you misaligned the float and its trapped the needle valve open. you only have one carb to play with so should be pretty straight forward tbh. take it off again, hold it upside down, remove the bowl & pull the retaining pin out of the float & make sure the needle valve is in its correct position and theres no crap under it. clean petrol is best for cleaning it out - dont advise you use compressed air (as some do) as it's easy to blow tiny parts all over the place!) the needle valve is like a little square bullet with a wire loop on the end. the wire loop goes through a tang on the float and as the float moves up & down it opens and shuts the needle valve, regulating the fuel into the carb. with the needle valve in place in it's brass seat, lower the float into position gently and replace the retaining pin. be very carefull you dont bend or force anything. then put it all back together, making sure you dont trap the float with the rubber gasket. job done. if youre not sure what to do, have a look in the free manuals thread for gn, en or gs125, theyre all the same iirc. post back if you still have issues. *if it wont start its likely to be the idle jet / pilot jet thats blocked. the main jet is the larger one in the centre with about a 1mm hole. the pilot jet is recessed in front of it, small flathead screwy will get it out - dont force anything. you will see a small hole in the centre, about 1/3mm and several lines of smaller holes up the side of the long jet. you need to make sure they are all clear. rinse it in clean petrol and if you need to poke it, use some fuse wire or a strand of stripped wire. do not poke a pin or drill through it ffs!. the holes in the pilot jet are much smaller than the main jet so its more likely thats whats blocked, plus you need it for starting & low speed running.
I'm off tomorrow, so I'm going to have another crack at it !! I had more trouble trying to connect it back up to the airbox !!!
lol, pull the airbox back to remove it m8, makes it a lot easier! then you fit the carb & push the rubber back onto it & bolt the airbox back up. might have to take battery off etc to pull it back.
Could just be the floats are stuck mate, dead common when carbs have been stripped down and worth a quick check before you remove the carb again. Get the base of your screwdriver under the float bowl and just give it a few light taps that should free it off. If not do as Benny says above and rip it off again. I am thinking with regards to your starting prob if you have put fuel down the plug hole and youv'e got a good spark it should go even if it missfires. If not i'd be looking for a compression problem mate not a fuel problem. if your having probs refitting the carb back onto the airbox rubber, heat it up with a hot air gun or hair dryer and spray it with a little wd40 it should fly straight back on. Got to say vfr 400 are the worst carbs iv'e ever had to put back on a bike :yellowcard: Let us know how you get on :thumbup: I know they aren't the same but here is a pic of some Bandit carbs i cleaned out last yr, these feckers had sticky floats when i put em back together and pissed petrol all over me lol Here are all the jets layed out We used to use an ultrasonic bath to clean the jets out ect
Cheers Guys ! Tapping with screwdriver worked ! I have now got it running, although I still think something is a bit blocked. I can throttle up a bit but cannot close the choke fully (running for 30 minutes). Is there something I could add to the fuel, Redex ? etc to help clean it, or am I going to have to take off carb again and clean it thoroughly ?
From what I understand if your saying the bike wont run without the choke on then I reckon it's leaning off somewhere because the choke is making the mixture richer. Have you put the carb back onto it's rubber/airbox properly mate Have you messed with the pilot screw settings?
