try a hotter plug as it could be a dud plug, faulty lead or coil. this is the cheapest start,recheck the carby and if no joy try another carby set. could the choke be jammed on on that carby? could also be faulty valve guide seal?
Hey Doug If you can hold out till next week, Chris will be home and I'll check what he has available. No guarantees!!!
Ok so I went MAD on the carbies today in an attempt to see what could be done. Pulled them off all apart, threw some new float needle seats in the 4, readjusted floats to match and threw them back together. Was expecting nothing.... But the bike works a lot better all of a sudden!. It's dropping back to idle fine, revving well and not cutting out. Going to get it registered (Or attempt to) on Tuesday! Very excited. Only thing to iron out is it's still bogging down between 7-9k RPM. Fuel/Air maybe??
Ahh carbies! I got mine to run better after a clean I still have some problems though. I have a 6-8k deadish zone. I'm going to throw a seal kit in it when I have a 2 week break in December.
Bravo and well done, good to see a plate on the bike. Have you had the carbs calibrated, amazing what difference that makes. Time to hit the road.
Well I've had the bike apart for some time now while I tinker/rebuild the carbies I finally got round to checking the CDI box today............................. SIGH So theoretically speaking the Engine number on the engine says ZXR250C, so I assume the engine is from a C model. My CDI box, 21119-1263 suits an A model engine..... So how to tackle the issue. I can't just stick a C model CDI on because it's an A model wiring harness with the 4x4 pin setup. RAGE!!!! Idea's anybody....
if all the other electrics are a model i cant really see the problem as the engine would only be the block and internals.
Agreed... to the best of my knowledge the block, barrels etc are the same on an A to a C engine, your electrics are A model which means you have the right CDI..
Well that's a relief thanks guys. If my carb rebuild doesn't fix some of the issues I'm having with higher revving and cruising then I suppose I'll rule the CDI out till then
Woohoo! We finally have success. Got round to finally finishing the rebuild on the carbs and it looks like all is well. The bike runs smooth when cruising and revs a lot better now. It's seems to sound stronger too and that's always a good sign. Took it for a thrash up to Mt Tambourine on Sat great fun! Noticed a great thing about the bike, you feel like your going 200 because of the high revs but your not even doing the speed limit! Now to start working on the cosmetics. New fairings, paint etc. Still doesn't seem to want to rev past about 15k, it seems to start to drop off in power so I just change up. Hopefully just needs a bit of tuning now to sort that out. Keen for the next ride day though! Can finally tag along
Cool, lets plan a ride day in January... Im keen now my bike has some new boots and goes around corners
when you guys say that there is a "flat spot" between 6-8k, how does the bike behave in particular?? just remember these engines are only making good power well after 10k generally. mine will rev from 2k upwards in a very linear fashion without any hesitation, but certainly has some more balls after it clears early rpm - i remember one of my N/a V8's had a big flat spot right at 4k rpm, engine would hesitate and choke up slightly, then continue to revv freely, solution? new air filters, as the paper filter was restrictive. -maybe the same principal applies?
It's all good now Cal. Carby rebuild fixed the 6-8k issue. Only thing I have to work on now is the power starts to drop round 15k. I'm gonna try with the air filter out see if it helps but it's a high flow filter so I can't imagine it's restricting air flow too much. Probably just some fine tuning needed.
yeah thats a bit strange how the power cuts out, if it sort of hits a wall and can still maintain revv's, once again it could be a carb issue, - look at the float heights.
Ok guys thinking caps on SOO here's the issue. The bike is running great, starts first time every time, idles well and runs smoothly. However there is no doubt that it's significantly down on power, the power band it completely out of place (it hit peak power around 12krpm) and the bike will not Rev under load past about 15k. Now the Carbies are pretty much as good as they are gonna get, fully rebuilt and operating pretty much like new. I've tried adjusting the float heights many times, it makes small changes but does not resolve the issue. A few other things too when considering the issue. I've mentioned previously the C model engine and A model electrics (CDI and wiring) and everyone seems to agree that it shouldn't be an issue. Is it possible the engine timing on the C model is different to the A model, then that would create an issue regardless of the CDI? Even if the stock, barrels etc are all the same. Anyone's ideas/theories will help as I'm starting to look outside the box to fix this issue, everything standard has pretty much been tried.