One cylinder not working please help!!

[archetypalsin]

just like to say im new to posting but have used 400 grey bike so many times to figure out problems so id like to say big thanks to you all that take the time helping the mechanically challenged like myself........ This one has me stumped though. The front left cylinder is not working and when i say not working i mean its not firing. The story is is that i had a new generator put in, i then had a fault with my cdi after getting caught in some heavy rain so changed that i also changed the reg/rec and a new battery fitted, took it for a ride after changing the cdi and was running rough so found out the front right cylinder was not working so i changed the plugs had the coils checked and changed the ht leads and just for good measure i swapped the coils around just in case still no joy!....Any ideas anyone?? thanks

[skinnydog0_0]

Hi,
Just to get it right in my head,
is this the order things have happend?

1. new genny
2. new CDI
3. front right cylinder not working first?
4. changed the HT Leads
5. you then change the coils?
6. now the front left is not working?

Is that how it happend?

First i would check the plug in that cylinder, swap it to the rear and see if that cylinder stops.

Have you done anything to the carbs?

[archetypalsin]

It was new generator, new reg, new battery, new cdi, front left cylinder not working, new ht leads, new spark plugs and checked coils. Also just checked for a spark in the faulty cylinder and got a good spark so its not electrical. can it possibly be a fuel starvation??? or am i looking at piston rings/valves??? When i took the old plug out it was oiled up if it does come to rings/valves am i better looking off looking at a second hand engine? whats the cost of getting an engine rebuilt? Cheers !! Yeah reread my post meant the front left not front right !! see how that was confusing.. So just to clarify just the front left is not working

[skinnydog0_0]

Hi,
I would suspect that it's a fueling issue rather than a piston or valve. do you get any strange noises from that cylinder?
It might be worth taking the carbs off and giving them a clean, before you go looking into major engine works.

I would suspect that an engine strip and rebuild would cost £400 ish + parts, so makes cleaning the carbs a much better place to start

HTH

[hunter]

Also check the valve clearences could be tight on that cyl.