Fuel Problum

Horatio

Hi all,
Having a bit of a problum with my CB1 400.
Runs fine , revs perfectly in neutral and drives through the gears without hinderance untill you apply more than one quarter of the throttle. Then it feels as if you are running out of petrol. It just has no accelleration at all.
I have refulled 4 times so it can't be dirty petrol and have stripped off the tank and checked for anything visible. Also had the plugs changed. Still doing it !
Any help would be greatly appreciated
Thanks

bushy...

It sounds like the emulsion tubes are blocked ,rip out the carbs and clean them , they are the brass lads that te needle passes through.

Interceptor

Yep, fuel starvation alright. Is there a fuel filter on the line running from the fuel tap to the carbs? These can get blocked with gunge if the bike was laid up over the winter or the tank has water in it.

'cptr

May be a stupid question but:

Can you clean the fuel filter or is that a relace it job?

Elfish

Fuel filter is a replace it job.
Simple to do and <10 euro.

But if you're having a problem at higher revs but none at idle, it is not a fuel filter problem, more likely dirty carb jets/wrong float height/someone has been fiddling with carb where they shouldn't have been. That said, if the filter is dirty or cracked, it's a good idea to replace it.

Horatio

Thanks for the advice guys, looks like either way a strip down of the carbs and a good cleaning is in order, will advise if I find it's anything other than that

Horatio

Coming back from Wexford and the bike suddenly took off with high revs, apparantly the problum fixed itself without stripping down the carbs, must have been a bit of dirt or something in the jets or filter that just worked itself free,
weird but nice to have my bike back.

Pigeon Reaper

Had the same problem on a CB-1. Turned out to be a drop of water in the Carbs. I'd say you're as well off draining and cleaning the carbs. See if fuel is getting to them ok. Also check that you have enough vaccum without any holes or cracks from the airfilter down. This is just to make sure it doesn't come back. Nice bike by the way. Do you get classic insurance on it yet?

Horatio

I'm renewing my insurance this week with CN and yes I qualify for classic insurance, got a quote for 350 TPFT so
not bad. It is a great bike and just to be sure I 'll do that with the carbs, thanks for the suggestion

babybundy

it was probily the jets cause i had the same problem until i had them cleaned out how old before the bike gets classic insurance

Pigeon Reaper

I think CN give classic on anything over 15 years.