Dx4's NC30 is back but not right

[dx400r]

After much spannering, welding, swearing and hacksawing me and my NC began her first commute in almost 2 weeks. Long explanation cut short.

Its not running right. Havent touched the carbs/fuel system since the accident and past 5k it runs like its running out of fuel. No real power at all.

Two things may have contributed to this, one BAD one not so bad:

On the day of the accident it was chucking it down. When the bike was either over or being recovered could rain get into the tank and make it run funny?

When the bike got twatted it was over on its side with the throttle held open... needless to say the oil pump could have been sucking air.... could I have hurt the engine? It was doing this for 10-12 seconds before someone turned her off.

How can I tell?

It idled fine the other night but I wasnt trying to ride it as it had no brakes

Views/Thoughts?

[greggo]

Too many views and thoughts to list.

Running on its side can cause a world of hurt. I'm torn between 10-12 seconds is alright or disastrous. Worst case is hydrauliced cylinders resulting in bent rods and valve damage. That would make the bike run like shit everywhere, although worse at revs than idle. Engine won't last long. A compression test is a good indicator. Plus it usually won't sound right and blows smoke like a bitch all the time.

I'm more inclined to believe something else is going on. What did you spanner, weld and swear at? Start eliminating possible cuplrits with some basic mechanical, electrical and fuel checks. Because right now it could be anything.

A good hard knock can jolt a lot of simple things out of place, including electrics. You could even crack the ceramic on a spark plug, making the ceramic vibrate loose and arc to the cylinder at high revs thereby eliminating the spark to your cylinder. Seen that once. Try finding that!

[fastdruid]

5k, hmmm, is it possible you disconnected or jarred the derestriction or speedo connection?

If you don't have the speedo connected then it runs onto two cylinders over 5k.

Druid

[dx400r]

As of a few minutes ago I have put some stuff to dry out the fuel into the tank incase its that.

most of the spannering, weld and swearing pretty much was just fixing cosmetics. Any thing electronic was temporarily unplugged and replugged when I was changing my bent subframe. Seemed to rev fine the night before last (not riding it just observing) so im somewhat confused..

I know both the coils are connected securely, will have a nose around the sparkies/plugcaps tonight.

Will report on how it ran on my way home tonight.

5k, hmmm, is it possible you disconnected or jarred the derestriction or speedo connection?

If you don't have the speedo connected then it runs onto two cylinders over 5k.
Druid

Not sure this applies to me as im on the ignitec CDI. Clock connections were redone when I was changing the clocks bracket/main fairing stay.

[cbr400rrn]

Maybe you loosened some c**p in the carbs and it has got stuck on the needles if it was on its side.
May be worth a try to give the carbs a bit of a clean,

[dx400r]

Oookay post ride report from yesterday....

Get out side and theres snow on the bike:

Full choke start bike nearly dies and revs fluctuate 2 times until the carbs seemingly sort themselves out and it sits at about 4k.

Bike rides normally up to 5,000/5,500 then starts to act like it has no fuel but if throttle is held open it will surge its way up to about 10k where it doesnt seem to feel like going any futher. Engine doesnt make any real weird noises, induction noise is different but that makes sense as its not right atm.

It doesnt stall, crunch/clunk or smoke[afaik]... maybe it is crap in my carbs after all... will have them off this weekend as there is a nicer set sat waiting anyway. Just to be sure I shall check the oil while im at work - thanks for the thought cbr400rrn :D

[Neosophist]

Besides checking your carbs, check the battery / electrical system is ok, the shock from the impact might have knackered the battery (electrical problems often manisfest themselves as running issues)

Vaccumn pipe from fuel tank on ok?

[dx400r]

Okay time for an update folks.

I have fitted a different set of carbs and set them up as per the previous set. The bike seems happier revving now.

Annoyingly there is a new problem now. Start it, choke wide open and the bike only gets to 2,000rpm and revs slowly begin to die and the bike. I have to keep blipping the throttle over a period of 2mins to get it sit at 2k and not cut out.

A possible contributing factor:

I have found a melted charging circuit connection (the one nearest the stator). How long as its been like that im not sure. But it looks like one of the 3 yellow wires has charred severely enough to disconnect itself. This might mean the bike isnt getting all the current it needs to function right.

I can only imagine the reg/rec has failed at some point. Battery is fairly new. A correct diagnosis?

Thanks in advance folks.

Dx4

[CMSMJ1]

Your battery will not be getting charged. If the wiring is melted then worth your while whipping off the generator cover and making sure that this is also not knackered. If I remeber rightly you can do a resistance check down each of the yellow wires - should be no resistance between any of them - if there is, you have problems..

Good luck mate..

[dx400r]

11.75v - must be getting some charge. Wont be leaving it for long though. Got a R6 Regulator on the way from Mr France.... if I can get a chance I will check out the genny - no doubt going to be bbq'd as god knows how long its been doing this.

Sodding nc charging circuits... *grumble* *grumble*