Fuel squirting of tank vent one purge bulb pressed.

[Hunter]

2 hours ago, bmp01 said:

So you've got 2 fuel circuits in the carb, a low speed and a high speed.

Low speed circuit is fed via the bung in your blue circle and there is a little flap check valve on t'side. 

High speed circuit is fed via the small hole below the main jet / check valve assy.

If you have a piece of small dia hose, preferably soft silicone, you can hold one end over the entry hole and blow / suck to confirm the check valve operation. Adjustment screws need to be NOT bottomed out. Low speed circuit will flow a lot less than the high circuit.... 

 

Will check and report back. Thank you.

[bmp01]

4 hours ago, Hunter said:

Picture is for the working carb. The other carb Seen in picture to the left.

 

Ok, I hadnt realised that, apologies. 

 

The point about the purge bulb pulling in air is still valid - it shouldnt do that. As stated before either hose fit on the purge bulb fittings  is loose or the bulb itself is leaking. Always worth fixing things like this before they create a problem or symptoms you don't understand. ... 

Edited February 28, 2022 by bmp01
Question deleted.

[Hunter]

On 28/02/2022 at 12:13, bmp01 said:

Tested both check valve with silicon tube. Problem seems to be the idle check valve, I can blow and suck air easily in both direction with no resistant at all. 
I compare itwith my other working carb where I can only blow air in but when try to suck air I can hear valve click and close. 

I have ordered genuine second hand carb from eBay.

thank you all for your help. I have learned a lot from all of you.

[bmp01]

Thanks for posting your findings and well done in doing the comparison between good and bad carbs, you have some certainty there. 

So, these valves can go wrong in a range from the working parts 'just get stuck' through to parts completely missing. The latter is often the result of high pressure air being blasted through the adjuster screw holes.

There's a chance you can resurrect a 'just stuck' valve with carb cleaner, petrol, etc or ultra-sonic cleaning - basically you are just freeing up a tiny disk that 'floats' in the valve. Remove the  low speed screw to access.... start with low pressures and progress, not much to loose at this point 😈 😨

 

 

[Hunter]

All sorted now. Used but genuine  carb arrived from eBay, as expected it needed new carb kit. Fitted and saw up and running.

just got carb toned.
again thank you all for your help.