Cold downpipe... sorted but bigger problem help!!!

[castrol101]

The front left downpipe (as you sit on the bike) doesn't seem to have any gases flowing through it, the other pipe gets very very very hot within seconds of starting, the other pipe barely gets warm, and i checkd it after riding the full length of the M1!!! So its probably only warm due to residual heat. I have'nt noticed any power loss at all, though someone did point out that this problem could have been present the whole time i've had the bike.....

Any ideas???

Another problem i occasionally have is when i pull up to traffic lights, it idles pretty high before dropping back down to normal idle......

[DanieS]

It can be that it doesn’t have spark on that cylinder.
You can test it by pulling off the HT lead from the spark plug and see if it makes a deferens.
If everything stays as it was like idling and revving the plug can be dead or the HT coil.
If it does make a deferens I have no idée what it can be then.

My NC24 also hangs for a while before dropping to idle so I would like to see the reply’s on that.

[zimm]

sounds like its just not sparking on that cyl as has been said.

rev's hanging before dropping back to idle is a weak mixture/air leak.

[tanuki]

it could be something as simple as no spark and hopefully it is.

[Neosophist]

Pull the spark plug cap off and start the bike, see if it runs any differently.

One of my downpipes was significantly colder (you could hold it at idle) until I balanced the carbs.

[castrol101]

The carbs were balanced a few weeks back, but il try the spark thing when i get a chance this weekend and let ya know. Cheers fellas.

[shokrabi]

i have the same problem on the same cylinder but i am definitely getting spark and fuel.

[Neosophist]

i have the same problem on the same cylinder but i am definitely getting spark and fuel.

Have you had your carbs balanced lately?

If it's not running equally downpipes have a tendancy to stay cooler as the carb doesn't get to suck as much as the others.

[howl]

Hi mate
The easyist thing is take out your spark plug lay it in the head and spin the engine over , If it doesn't spark try a diffrent plug from another cylinder that does work ,If it still doesn't spark swap the plug caps over and try again then check the HT leads if no joy . You could swap over coils to test that if still no spark. Or test the coils with a multimeter each coil should have the same resistance .
OR if there is a spark there will be a bit of muck in the needle valve ,so not letting any fuel to that cyliner.
Worst case is that your cam has warn so much it doesn't open the valves ( this happend to a mate with a GSXR100 ) not likely though.
Hope its just the plug mate .
Did you get your spongy front brake sorted as I now have a vacuum pump to bleed them if you like
Cheers
Al

[castrol101]

Hi alec. Yes a master cylinder rebuild gave a large improvement. However i'm in lincolnshire at the moment until i move to leeds, so no longer reside in the lovely country of west sussex but thanks for the offer and all your help.

Back to the downpipe. Even simpler than i imagined, the HT lead was just hanging down the side of the engine and must have been the whole time, simply stuck it in and vroom vroom, sounds better than it ever has i was very happy, for about 5 seconds.

however, i now have a larger problem. All the fuel that was entering the cylinder will now be in the oil!!! So i will have to do an oil change, no problem.

Smoke was billowing out the exhaust relentlessly!!!! and for some reason the previously cold downpipe was also giving off a shite load of smoke! thought my baby was gna catch fire

Shut her down, coughed a bit and am now here askin you guys what else, if anything would i need to do/check, due to the bike apparently only running on 3 cylinders for some time.

Am i going to have run the crap out the system and deal with the smoke or what?? help please!"!!