Hi all, I have a 1973 T2 1600 with Bocar 34 Pict 3 Carb. I had a slight smell of petrol in the back of my bus and I read lots of comments mentioning that it could be where the fuel tank vent pipes join in the engine bay up behind the spare wheel well. I replaced the 2 inch section of pipe then went and filled up and put air in the tyres. I left it running while putting air in and noticed a sucking noise from the fuel cap. I went to drive it away and it spluttered and stalled the 10 minutes to get back home. I replaced the fuel filter in case it was blocked but made no difference. I took the pipe I replaced back off and it did run a little better but still spluttered and cut out so put it back again. On further inspection I noticed the fuel tank vent pipes were connected to the vacuum port on the inlet manifold by the PO, no idea why! I connected the pipes to the air filter as they should be and plugged the hole on the inlet manifold and now the noise from the petrol cap has gone. I cleaned the idle jet and tried to adjust the carb to get it to run. After lots of tinkering I have managed to get it to idle and run but with lots of flat spots, usually in 3rd and 4th gear it will splutter randomly and by no means running smooth but not sure if this is now the carb because it idles fine and moving the throttle cable it sounds smooth, it's only when it's under load. I would be grateful for any suggestions, help anyone may be able to offer because I am running out of ideas. I can't believe this has all come from replacing the 2 inch second of pipe!! and can't think what else could cause these problems just by having the vent pipes connected to the vacuum port for about 10 minutes! Chris
Just a thought but if your breathers were connected to the vacuum port and there was an air leak, which you've fixed, that would account for the sucking noise from the filler cap as you'd be drawing all the air from the petrol tank and causing resistance to the amount of fuel pumped to the carb Also, if it was set up to run with that set up by the PO the mixture would be all over the place because of the additional air / fumes entering the engine and maybe this is the problem if the pipe you replaced was perished Food for thought but hope you get it sorted soon Mr B
Mr B, You have described it exactly, the vacuum was created and the mixture all over the place. I have taken the plunge and got a second hand Solex because I've read so much bad stuff about the Bocar!! the trouble is there is no port on the front of the carb where I had a hose connected to the left input on the top of the oil bath air filter. Does anyone know what this port on the air filter does? is there anywhere else I can connect it to? Chris
Thanks for the reply zed, yes I have that port plugged at the moment. I will connect that up and give it a go. Thanks
Update: Just want to say thanks all for your help on this, I fitted a second hand Solex, adjusted it slightly and all seems to be running good, idling a little fast but while its running ok I'm afraid to touch it again! Chris
