Broken Super 4. Can anyone help?

[jaytee]

Hello everybody.
I have an intermittent problem with my CB400 Superfour. It will be working fine for a bit then it will start missing and the revs won't pick up at all unless the choke is on. Sometimes if you leave it for a bit it starts again and will go 10 or 15 miles down the road then it will start playing up again.
I though enitially it was a fuel blockage somewhere but i checked by undoing the fuel drains on the bottom of each float bowl and fuel was in each bowl.
Has anyone one got any ideas.
Thanks
Jay

[superfourben]

When the engine starts dying out is the headlight going very very dim at the same time? Might be the charging system not able to keep the bike running at low revs, if so will probably be a dead regulator rectifier. Otherwise low idle speed, cruddy carbs, buggered air filter???

If it seems electrical this should help.. just download the pdf

http://www.electrosport.com/technical-r ... -guide.php" onclick="window.open(this.href);return false;

[meno]

could even be a coil or plug breaking down at certain temperature?

total wierdness was my bikes speciality before i got there in the end.. with a massive input from these guys on the forum.

may be worth reading some of the posts in workshop section the guys helped me with.. including what ben said here

[meno]

was just thinking about the fuel tap too.. relatively easy to do this incase its yer vaccuum playing up. worth a try m8 good luck




http://www.akhara.com/nc30/fueltapmod/index.html" onclick="window.open(this.href);return false;



again some of that is listed in other parts of cb400 general/workshop i think

[amorti]

Something as simple as the fuel tank breather? Does it do it worse with a full tank?

[meno]

vry good point, if ya got a spare key u could ride till it starts doing it then open the cap with yer spare key.. if it returns to normal defffo breather

[jaytee]

Hi
As it turns out the earth bolt on the ignition coil had some how removed it self from the frame, so i cleaned up the contact surfaces put in another bolt and hey presto.

Thanks for you input chaps :0)

[meno]

yayy cheapest fix ever... glad youre sorted :D

[superfourben]

Brilliant, glad it was a simple fix! :D :D :D