getting closer

dunk 1 · Post by **dunk 1** » 22 Aug 2008 16:27

the problem i have with the bike losing the first cylinder after about seven miles seems to be definately fuel related but i am still exasperated by the cause. the conclusion i have come to at the moment is that it is flooding. The last two times i have been out and the problem has occured i have turned off the taps and run it till it drained and the problem went away. But what is causing it- i fitted new floats a while back - the white ones -and today it got a new float needle and valve and guess what - it had no effect whatsoever same problem again- arrgh - all suggestions welcome.
it does seem to run a little rich - could this have an effect?

3narf · Post by **3narf** » 22 Aug 2008 21:31

What year is your bike? do you have metal or rubber inlet manifolds?

3potjohn · Post by **3potjohn** » 23 Aug 2008 07:37

Is the choke really off when it's off? I cannot think exactly how the design on these carbs functions without re-stripping one of mine but at http://www.dellorto.co.uk/editor/upload ... HBdiag.pdf
there is a small o ring seal. I have had similar problems with a Bing carb where a choke piston seal had degraded. Plug went black,poor starting and running.

dunk 1 · Post by **dunk 1** » 25 Aug 2008 14:44

it's a 79 sport turned into a strada-or is it a strada with a sport engine? the inlet manifold is rubber and I have replaced the O rings at the top and bottom of the choke.

The bike starts very easily- first or second kick but does not need any choke so perhaps this suggest something. - thanks - Duncan

dunk 1 · Post by **dunk 1** » 30 Aug 2008 12:46

i've just dropped the needle on the slide on the front carb one notch and taken the bike out for a spin- twenty miles with no problem and the plug is a much healthier colour.The bike now needs choke on both cylinders to start but they are working well. Does it matter that the carbs now have different needle settings or is it that they get what they need seperately as long as they get the job done?

well lets hope this is sorted but I,ve been fooled before.

thanks - dunk

3potjohn · Post by **3potjohn** » 30 Aug 2008 18:30

Sorry if you already mentioned it-were the needles and jets renewed as you can get wear in these due to vibration-I am afraid I did not note my carb settings at rebuild other than doing one at a time.I should learn. Sounds like you have cracked your troubles. Today the sun came out too.

dunk 1 · Post by **dunk 1** » 30 Aug 2008 19:07

I'd previously replaced the needles and the atomisers (needle Jets ?) but not the main jets but as far as i know it is the first two that would wear - still went for a later 35 mile run and everything still ok although the sun didn't comeout in Cumbria.
thanks- duncan

dunk 1 · Post by **dunk 1** » 15 Sep 2008 18:46

just to let you know if you've been following my problems -this sunny Sunday I took the bike on a long trip through the back lanes of the lakes with no problems at all and great fun - its what I bought it for - just a pity that with hind sight it could have been done a lot quicker.
Thanks for all the help so far-Duncan

3potjohn · Post by **3potjohn** » 16 Sep 2008 06:39

Excellent news. And it looks good all week,at least down here.