Problem starting zxr250

[lpearce]

Having problems starting my zxr 250 (just bought it).
It seems like its got heaps of juice in the battery because it will crank over for ages without signs of going flat but the engine will not fire up at all. I can bump start it easily though and it runs fine. I would have thought that if the battery has enough grunt to continiously crant the engine over it should have enough to produce spark. The guy I bought it off said that the battery was rooted and that the starter was drawing all the current not leaving enough to spark it properly . Is that possible.

[slopster]

Problem is definitely not the battery. If it cranks for ages the batteries good - i've had battries that only crank for a couple of seconds still start the bike. Zxr's flood easily make sure you start with no throttle and immediately put the choke on when it starts. I don't think floodings your problem though but thats all I can offer. Seems strange that it is easily push started.

[qldzxr250a]

simple. have the rectifier checked out.

almost certin you will find thats the prob. very common.

i know this cause i had exact problem at start of year.

[lpearce]

I have pulled a plug lead off and checked it for spark while cranking it over and it has got spark (looks quite week though) Would a problem with the rectifier cause a week spark or would it normally just lose spark all together if that was the problem. I think I have a spare rectifier that I can try anyway.

[qldzxr250a]

problem with rectifier has to do with the current passing to and from batt so safe to say could be affecting.

not to expensive to replace (about $130aud i paid) or have looked at as it is just under your fuel tank.

[qldzxr250a]

see these posts:
this was my post earlier this year
http://www.kiwibiker.co.nz/forums/showthread.php?t=13754

and also superdave's post more recently:
http://www.kiwibiker.co.nz/forums/showthread.php?t=18225

both were solved by repalcing the rectifier.

[lpearce]

Ok, So i replaced the battery and Now it fires up, seems batteries can still have power to crank for ages but not have enough current to create a decent power supply for the spark. Anyway thats sorted .....NOW the dam thing wont idle and if I try to give the throttle a twist it just kills it. It wont run at all unless it has the choke on about half to 3/4 even after its warmed up. Then of course it dies ends up flooded then wont f%#ckn start again back to square one. Any ideas? I think I might just take it up the local shop and get it tunned and let them f@#ckn sort it out. It has been running sweet though the other day when I jumped it, it was perfect. It has been running on Av-gas and now is running on 98 so It might need just need a tune. A new set of plugs probably wouldnt hurt either.