Misfire and strange front brake problem

Hi All,

Over the last 6 months my bike has started playing up, the first problem is a misfire, well, more like a complete lack of firing on one cylinder, my old T reg curvy did it but just fixed itself before i sold it and my Y reg curvy has now started doing it, not all the time though.

What happens is, generally when the revs are low, one cylinder will stop firing and the rev counter drops, but it keeps going on one cylinder and after a 3 or 4 seconds it kicks back in and all is fine, i have checked the CDI connector and all looks ok, anyone else had this and should i start looking for another CDI unit?

Second problem is my front brakes, they barely passed the MOT as they are not uniformly applying pressure, basically, when braking with a constant pressure on the lever all is fine until about 20mph, below this it feels like there is grease on the discs and the front end kangaroo's, but the lever does not pulse at all, it has brand new discs and pads and a complete caliper overhaul, the runout of the disc on the wheel while on the bike is 3 thou, my other old suzuki that does not have this problem has a runout of 10 thou so guess this is not the problem.

I have not checked the head bearing myself as the MOT passed them, the wheel bearings are all fine as well, anyone got any ideas as both me and the MOT guys are stumped and i would like to get it sorted.

thanks for any help with either of these issues.

Rich

For the mis fire thing I'd look at the choke plungers and then at the Reg/rec either can be known to cause these same problems. If the problem is only occuring when running the bike on a wet road or after washing it then its none of the above and all you'll need is a fender extender. What is happening in this event is spray from the front wheel is wetting the front cylinder spark plug and it takes a couple of fires to dry it out.
As for the brakes I've no idea but squid or YC will be along soon enough to tell you what to look for there.

[Viney]

Sooty, as said, the chocke plungers, carbs (Blocked jets etc), dodgy plug (Swap plugs round), HT Leads, and coild could all provide this issue. Also if its only when raining, then its the water in the frontt plug issue.

Brakes, hmmm, when you say an overhaul, what does/did that involve? If the pisotns are all coming out at different rates, then they need to be FULLY stripped, cleaned, and possibly new pistons/seals. Both pistons in each claiper should come out together. Grabbing at straws really

Sorry, didnt explain that properly, when i say the revs drop, i meant the rev counter goes to zero even though the engine is running, from memory the rev counter runs off the CDI whichwhy i thought this may be at fault.

As for the brakes, i took them completely apart and cleaned them and new seals, all seemd to be fine when put back together, but made little difference.

thanks
rich

HT leads, dizzy blonds' bike the same mis-fire problem. The copper in the HT lead was all corroded. replace with graphite core stuff.

[yorkie_chris]

Sounds like you have some crap on brake disc. Give them a good scrub with some wire wool and lots of brake cleaner.

For running issue if you are losing tacho then you must have a problem on the LT side of circuit. Check the connector for the front coil.