It is difficult to know what the gasoline level in the bowl is, but the float level is easy to measure. The spec is 23,5 to 24,4mm. The actual is 24 see also http://www.ducatimeccanica.com/float_levels.html
When the gasoline runs out, the level in the bowl drops and naturally the mix gets leaner. The right mix is possibly achieved at a much lower level than the normal level. This phenomena is therefor no sure sign for a wrong float level.
I have the bike running now. The problem appears in the idle circuit. When I open the airmixture screw 2 full turns more than the factory setting (1,5), the bike runs much better. I have to test a little more and see the colour of the spark plug, but the bike is very responsive and easily lifts the front again. I expect that with a little more tweaking I get it right.
Sorry for the delay, I was travelling for some time.
The bike is the earlier version and i am sure the carb is a PHBH.
I did see the video before. This is what bothers me. The carb is realy not so complicated, not much that can go wrong, but still..
I found on a German website the confirmation that the jets I have are correct.
I now replaced the float, and the jets and the cold starter plunger.
Unfortunately there is no improvement at all, so i am clearly missing something.
I was doing a test ride with just little gasoline in the tank. When it almost ran out the bike went as it should, so too rich is certainly the issue.
The float height is perfect, the float valve new.
I am completely lost now. I could buy a new carb, but it frustrates me no end that a bike that ran well before does no longer run because of a cleaning of the carb.
I hope anybody has a sugestion for further investigation
an update. I cleaned everything again and checked all the bits. The vent openings and tube work fine and the tank builds no pressure, which could have been a explanation.
I am now wondering if a jet is missing. I see that on the drawing there are 2 jets for the iddle, both in the same channel on top of each other.
I have only one jet (the upper I guess). It has a number 60 and it is a diffusor (with a small tube with side holes). Could it be that this particular bike only uses one iddle jet, or could it be that I lost the other jet? In that case does anybody an idea what jet I should try?
Montesa 314 Too Rich?
in Montesa
Posted
Hi Chuck
Thanks for the suggestion. I did check the reeds before, but you are right, I will check again.
I now know that I need a magnifying glass to see some of the issues. Not sure if it is my age or the sensitivity of the bike..
This way I noticed a corrosion inside the old needle jet diffusor, as if eaten by the wurms (magnified..)
This PHBH carb certainly has an air mixture screw. Its setting seems to have a big effect on the first half opening of the slide.