VFR400 NC30 Not running, possible electric issue?

[burningalive409]

Sorry if this has been covered before. If so, please direct me there thanks.

Well the bikes been sitting for a while, And i decided to try get it running again tonight. The battery was too flat to start the bike, so i jumped it off the car.

It started after a few coughs etc, as expected. But it had a splutter/misfire? Like one or two cylinders arent quite firing? and on full choke it used to sit at 5000 rpm, it was sitting about 2500?
I disconnected the leads from the car after about 5-10 minutes of the bike idling (on choke) And it cut out. I re-connected the leads, and started the bike again. I now noticed that the neutral light was flickering in time with the stutter. The bike would occasionally catch and run fine, on 5000 with choke and 1500 without. It would then cut back down to roughly half this, stuttering again. When i gave it throttle, it would rev to 6/7000 and refuse to go any further. I also noticed some smoke coming from the back of the two rear cylinders, not sure what this was? (Possibly just need new plugs?) Also noted that the coolant overflow was empty. Like, completely dry.

If you could please help me, as i would be very happy to get this bike back on the road asap! Tempting to just put it to a dealer though.

Thankyou,
Fraser

[CMSMJ1]

you need to be sure that the battery is good.

Also, that there are no blown fuses - especially those relating to the dash, horn etc. If the CDI cannot "see" the speedo then you cannot get it to fire on 4 cylinders above 5.5k revs.

How long was it sat?

[burningalive409]

I checked all fuses in the block under the pillion seat. I checked all lights, indicators, horn etc before i started the bike. Im pretty sure the batterys gone, but shouldnt it run off the alternator once started? its been sat for about 6 months

[burningalive409]

Also, its an aftermarket HRC mph speedo, but its ran fine before with the current speedofitted so cant imagine thats the problem?

[CMSMJ1]

it won't run properly, if at all, if the battery is fucked. Alternator cannot run the bike.

That needs sorting.

What is HRC about the speedo exactly? If you have not got a std speedo, or there is not a speedo derestrictor box then it will trigger the 5.5k revs issue.

Check them out

[burningalive409]

So a new battery, and fingers crossed?
It is a branded HRC speedo, came on the bike, never caused any problems till the bike was sit for a while, so i doubt this is an issue? Its also got a standard reg/rec, should i replace this with the new one with fins just to future-proof? Could this actually be the problem? Ill get hold of a multimeter tomorrow hopefully

[burningalive409]

I connected a spare battery, and it started fine. The back cylinders still arent running right, (1 and 3 i think they would be?) The left hand cylinder (1) would occasionally catch and run, and if it cut out some very slight throttle would let it catch and run fine again. I do not believe cylinder 3 runs atall, and when i splashed water on the exhaust it was still cold. i then took off the airbox, not sure why. i put my hand over each trumpet, and could feel the compression/vacuum from each cylinder but nothing from cylinder 3. Could this be because its not running, or a possible leak in the rubber?
Thanks,
Fraser

[Cammo]

It sounds like the plugs are stuffed.

[magg]

Do you have fuel flow to all carbies? Are the cabry jets clean?

[burningalive409]

Plugs could well be gone. Ill pick up a new set as soon as i can, or swap the two rear ones to see if that makes cylinder 3 fire. May also pick up a new/used coil off ebay for the rear, since one of the ends on the ht lead is not oem and looks a little dodgy. Unsure about how clean the carbs are, hopefully fresh fuel will clean them? What all do you recommend doing before it goes back on the road after sitting for 6+ months? Just a basic service? (oil, filter, air filter, coolant, plugs)? Thanks