GSXR250RR GJ73A Won't Start!!

[Gimly56]

Bike wasn't running too flash, sounded like the carbs needed balancing possibly? As it won't idle correctly....it's like it has a flipping mind of it's own!! It will start revving higher on it's own accord just sitting there??!!

So I ride it in this condition to the bike shop and the mechanic tells me to take it for a good long 100km/h blast and then if it's running like crap to take it back to him.

46km later and disaster strikes....

Bike just started to die slowly?? Got to 60km/h and had no throttle response. I pulled over and let the throttle off and she stopped completely. Wouldn't start again. 5 minutes later I manage to get it started but it sounds way off and out of balance and I swear it was making a knocking noise, so I quickly kill it.

15 minutes later I restart it and it's running rough, I mean ROUGH...limp it home.

NOW it won't start at all!! Turns over freely but occasionally backfires and doesn't even sound remotely interested in starting??!! Checked the plugs and they are all getting spark. Carb bowls are all getting fuel. It's like the fuel isn't getting from the carbs to the inlets somehow?? Could this be a case of jammed valves???

I don't think the bike was EVER running on all four cylinders??

I ripped off the carbs and open them all up and check the jets and they all seem fine, no blockages....OOPS!, first school-boy error... the two main jets are the same thread and I can't remember which went where?? So I chuck the jet with the larger hole in the gap with the larger hole as well and do that on all four carbs.

Put the carbs back on and hook everything up and nothing, still no start. ??!! Now I'm thinking timing?....valves?...coils??.....cam chain??

Oh and as a side issue, when I took the carbs out I also removed the cam chain adjuster and it appears to be seized?? But I figure that shouldn't have anything to do with my current issues anyway.

[Gimly56]

Ok, so bit of an update. Petrol tap has been tested and is working fine.

Checked the timing and that is also fine.

Still not getting petrol to two of the cylinders....so I think it's the carbs. Am going to take them out AGAIN and recheck everything. I think an O ring or two might be knackered after 20 years?

Am going to try to crash start the bike this afternoon to see if that helps at all. Have read on here a few of the 400s just have major troubles starting after being pulled apart, so will persevere.

[Gimly56]

Still won't start....hence the photo I took today of the 'progress'......fairings off, airbox and petrol tank off....

I'm baffled as to why it won't start??? It's being towed to the bike shop tomorrow. I'm going to cross my fingers and pray that it doesn't cost me too much!!

http://i992.photobucket.com/albums/af41 ... ogress.jpg

[Gimly56]

Got it sorted!!!

Put a new set of NGK CR9E spark plugs and sprayed some 'Start Ya B*stard' near the carbs and YEEHAAA!!!

My baby is back in action & runs like a sewing machine!!!!

Only one negative....and that is carb#3 is leaking slightly from the float bowl......chucked some gasket sealer on that today though and will test it out again tomorrow. Should be fine? Can't source carb rebuild kit in NZ so will have to work with what I have.

Super psyched to get my bike running again though. MASSIVE!!!

[Gimly56]

Haha checkout the air filter on my bike. Standard air filter taped into place by the previous owner. Mint. Works though??

http://i992.photobucket.com/albums/af41 ... otchup.jpg

[Gimly56]

Finally figured out what was wrong with my bike this whole time. One of the coils was poked, so number 1 cylinder wasn't firing at all.

This coupled with the old carb setup was actually literally killing spark plugs!!

So...new coils and the bike is a mint runner.

Just wanted to update this thread in case someone has the same problem down the track.