ZXR250 - the saga continues...

[magicmonkey]

So then, having got myself well and truly pissed off with trying to fix this bike up I decided to focus my attention on anything other than it for a while. Now I've left it alone for a while and realised that I really want to be back on 2 wheels pretty soon so I'm back to working on it again, this time with a bit more patience in stock!

Currently the problem I'm having is that the engine just won't start. I can hear a cylinder or sometimes 2 catch but it won't actually kick into life. I also get backfires while turning it over and occasionally about 1 second after taking my finger off the button.

So, the engine relevant things that have been done to the bike so far are:

• Carbs cleaned and re-jetted back to stock
• Timing set back to stock
• Valves lapped (one needed to be re-ground, had an engineer doe that though)
• Clearances adjusted
• New head gasket
• New spark plugs
• New leads
• New oil and filter

And so far I've made sure that there's fuel getting into the cylinders and that there's a strong spark. One thing I did notice is that while checking the resistance on the IC igniter it had no relevance to the manual at all, the manual is for a C model and I've got an A model though so it may be that it isn't meant to relate.

Things I'm going to be testing over the next few days are:

• Compression test
• spark plug arcing gap
• Ground connections
• Pilot Screw fiddling around

I'm also intending to try and work out why it's backfiring as I think that'll give me a pretty good hint as to why it's not starting, I'm a bit stumped as to how to go about that though.

Just posting to see if anyone could think of anything else I should be looking at or give me any more handy hints, bear in mind that I'm a complete mechanical noob though!

[bogan]

checked that the plugs are all sparking at the right time? timing light does this pretty good.

[magicmonkey]

checked that the plugs are all sparking at the right time? timing light does this pretty good.

Nope, that's something I know needs to be checked but I have no idea how to check, also don't have a timing light! Is there another way of doing it without the timing light?

[bogan]

Nope, that's something I know needs to be checked but I have no idea how to check, also don't have a timing light! Is there another way of doing it without the timing light?

not really, as you have to check a specific plug is firing at a specific rotation, while its rotating, maybe a high speed camera could do it, but I reckon a timing light is a little cheaper!

[MSTRS:Me]

2 coils each feeding 2 cylinders. Are you sure you got the leads the right way round?

[magicmonkey]

2 coils each feeding 2 cylinders. Are you sure you got the leads the right way round?

You know what, I was just checking that while you were typing! I went completely over the wiring diagram and wired them as per that and as I was checking the pickup coil page in the manual I noticed that one of the pictures for the plug wiring looked a little odd, on closer inspection it turns out the the pictures and the wiring diagram have them wired up in a different order, that's something I'll be trying the second I get in the door, can't believe I didn't notice that before though as I've been going over that chapter like a madman the last couple of days :s

[magicmonkey]

not really, as you have to check a specific plug is firing at a specific rotation, while its rotating, maybe a high speed camera could do it, but I reckon a timing light is a little cheaper!

Sweet, thought that was probably the case, but it never hurts to ask Just found one on Sulco for $100 but I'll have a check down supercheap over the weekend as well

[magicmonkey]

Fair warning to ZXR250 owners, beware the electrical section as you'll find cylinder 2 and 3 wired back to front in one of the diagrams

[magicmonkey]

ha!! It was a problem with the leads going to the wrong plugs and it's now starting Needs balancing and all the rest of it but for now I'm pretty damned chuffed with that. Thanks for all the help guys, I never would have thought to just swap the leads around were it not for this thread!

[MSTRS:Me]

You will learn that of all the things that can go wrong, the culprit is usually the simplest one. Sometimes that means the owner...

[magicmonkey]

You will learn that of all the things that can go wrong, the culprit is usually the simplest one. Sometimes that means the owner...

heh, I couldn't begin to tell you how many things I've cocked up on this bike so far! I've managed to fix all the problems I've caused though and I've learnt one hell of a lot as well, mainly thanks tot he good people on here

[bogan]

good to hear dude, just in time to get her on the road for summer eh

[magicmonkey]

good to hear dude, just in time to get her on the road for summer eh

yup, now I just need to balance the carbs, replace the sprockets/chain, replace the fork seals and put in some fresh brake fluid

I'll have all the cosmetic stuff to do after that like sanding back and treating the exhaust, fixing the fairing etc but that's just stuff that can be done while it's in use

[Katman]

yup, now I just need to balance the carbs, replace the sprockets/chain, replace the fork seals and put in some fresh brake fluid

[anton]

Hey guys i think i need to replace the cam chain on my zxr250 do you guy do spanner nights? i would love to come and explore the bike i can possibly even host one at my house.) i got the manual for the bike but it is in poor quality does anyone have a copy? thank you guys