[dablowfly]

hi i have a 93 gsx250f across i had a problem with it not starting but sorted it out found out to be dodgy plugs put them in fired up but sounds like she only starts on 2 cylinders then picks up after a couple of seconds if u give any throttle or even use the choke wont start and just floods it any suggestion?

also once running shes ok but when u accelerate it drops down prety much straight away until it get to about 3000 then holds there for about 5 sec then dropps down slowly.

also there are 4 screws ontop aff carby at the front does anyone know wat these should be set at?

and should the throttle sides move up and down freely if pushed to top should they return down?

sorry ppl im mechanically minded just new to bikes planning on getting the across going to learn on heard that there a great bike to learn on

This post has been edited by dablowfly: 05 February 2011 - 09:25 PM

[kiffsta]

Hey Mate

I'd say your carbs are gummed up and need a decent clean. Mine did exactly what yours is doing, I bought new pilot jets and new main jets and fitted them ( cost about $100), I also removed and cleaned the emulsion tubes which were clogged.

Finally, the top screws on the carby are for your air fuel mix, they should be set to 1.5 turns out, however you need a carby balancer to get them 100% right. Once that is done, fit some new plugs, fresh oil and you should be sweet.

Cheers

Chris
www.2fiftycc.com/forum

[dablowfly]

kiffsta, on 12 February 2011 - 11:47 PM, said:

Hey Mate

I'd say your carbs are gummed up and need a decent clean. Mine did exactly what yours is doing, I bought new pilot jets and new main jets and fitted them ( cost about $100), I also removed and cleaned the emulsion tubes which were clogged.

Finally, the top screws on the carby are for your air fuel mix, they should be set to 1.5 turns out, however you need a carby balancer to get them 100% right. Once that is done, fit some new plugs, fresh oil and you should be sweet.

Cheers

Chris
www.2fiftycc.com/forum

[dablowfly]

cleaned the carbs today but now wont start at didnt look to be dirty already put new plugs due to it not starting before and it started but had this problem from then a guy hade it for a few months and dont know wat hes done but its seems to have a weak spark i mean weak i can hold on to a bit of wire put into the and off the plug lead and only get a small jolt im mean a lawn mower puts out more ooommff than wat this does so why would that be?

[Siddy]

Try starting the engine by dropping a little fuel into the air filter, if it starts easily after that you know its a fuel problem and not an ignition problem.
If it's fuel, take the carbies off and check the fuel bowl is full, reset the float level, put back in bike, turn on, wait for the fuel pump to fill them up then take them off again and see if they are filling.
Here is some other advice for the carbies (but does not really affect whether the bike will start or not). Open the top of the carbies, the 2 circle caps with 4x screws each. Be careful and lift the black rubber diaphragm underneath, you will see two black plungers for each carby. The white plastic thing that hooks each plunger on don't last long so get a new set of 4:
http://www.suziparts.com.au/ p/n: 13511-38400, $5.
This area of the carby should be very clean and dry, if not - make it so
Unscrew the underside of the carby (the fuel bowls, clean them out and clean the rubber gasket being careful not to break it. Look for corrosion inside the brass jets, if they look bad get new ones or try and fix them with a drill bit of the same bore size.

If all that didnt work, maybe it needs the choke but your choke isnt working?
14m spanner to undo the two choke cables from the 2 carbies. Pull it all out, it should be the cable that sits in a brass housing, then a long spring and then a brass holder with a thin pin on the end which is all held together by the cable inner. Be careful cause its only being held together by the tension of the spring and it all falls apart very easily. To put it back in, assemble it and then gently slide it in, trying to feel the thin needle end is going into its home. When correctly installed you can hear it actuating when you open and close the choke from the handle bar if you put your ear near the carby with the engine off.

If dropping some fuel into the air filter didn't help, try measure the resistance of the ignition leads, if they are too high get new ones.
Take 1 spark plug out, reconnect its lead and then push the threaded part of the spark plug against the body of the bike, try and start the bike and watch the spark in the plug, should be small but bright white sparks.

I know this thread is old but I had the same problem with my bike, I am not sure which part cured it cause I did it all at the same time with new plugs and everything, just posting this if someone else stumbles across this thread.