It’s all gone horribly wrong, again went to take the rocker cover off to adjust the valves and a mini flood of pizz thin oil flowed out. Stinks of Petrol and is visibly much more clear coloured than oil. Dipstick has also gone up about 1.5 inches. So fuel in oil 100% and quite a lot. any idea of the cause? I have twin Webers ICT 34s. In summer I fitted Malpassi regulator and gagged back to gauge measured 2.1psi. A year back I fitted two new needle float valves and calibrated as per instructions to ensure proper float height. This seems to have happened over winter sitting in the garage. Has been only idled a couple occasions times in the garage, so no running on the road so hopefully engine shouldn’t be affected… obviously I need to drain oil. Fix issue and refill. Any ideas where to start looking?
It can only be those float valves again. Maybe with the arse end in the air while you have been messing with the starter the angle of the float puts less pressure on them. Seems to me Weber carbs are bad for this.
1.4 bar is about 20 psi, you should have 2½ to 3 psi. Allowing the engine to idle during the winter is a bad idea, either start it and drive it or don’t start it.
You need to run it more ..stop things jamming up . If you don't like driving your bus in the salty roads ..pick a dry day . A fuel shut off valve helps but doesn't necessarily rectify the initial problem . At least your oil galleries will be whistle clean . I am not a carb boffin but someone will put you in the correct direction .
Plugs out, drain oil, leave for a few days with oil breather off, drain plug out rocker covers off, anything you can think of off that lets the case air. You might want to turn the engine over by hand with the plugs out and see what comes out the plug holes (petrol). No smoking. I would disconnect battery earth first unless it stinks and might spark at the terminal as you disconnect. When you refill, leave the plugs out and turn it over until you have oil pressure and a bit longer. Plugs back in, start up. Change the oil filter and empty the external cooler if you have one/both as you've run it perhaps with petrol in it.
Also when you do start it up, give it a few revs for literally a few seconds, like 2,000rpm to splash some oil up the barrels, don't just let it stutter into life - I suspect you have to do that and more anyway with no chokes to keep it going.
Weber woes, get Viton tipped valves from Eurocarb Also, it's worth considering a fuel shut off solenoid
I don't think they do the Viton ones for icts do they? I cant see them on their website anyway (although its a ball ache to find anything on their website to be fair)
I had new valves in my IDFs when this happened. Fuel solenoid really is the solution. I had one but it's not obvious which way the switch goes - ask me how I know. The "On" refers to the override not the shut off! Edit: this is the one I used, or one like it https://www.ebay.co.uk/itm/Petrol-d...2349624.m46890.l49286&mkrid=710-127635-2958-0
Neither have I. ICTs are nice little carbs - nothing special - but they do seem to suffer from this. Why is a mystery.
For the “ less knowledgeable “ how does this fuel cut off work. Is it the same as the type linked to the fire extinguisher kit , or a totally different thing. I have a single port 1641 single carb so may not be relevant to me ?
I’m liking this! Feeling a bit peeved as I fitted a fuel regulator and new float needles and set the float height etc. you’d think that’d be enough for a few years. I don’t want this to happen again and this should guarantee fuel cut off when garaged
Just a solenoid-operated valve in the fuel line to shut off the fuel supply when the ignition is switched off. Their most useful purpose is to stop the tank gravity-feeding fuel into the engine compartment if the engine catches fire (a Bay has the tank higher than the engine).
Thanks, I have fitted the cut off but thought it only became active when the extinguisher activated . From memory it is powered from the coil. …So does it mean that until I switch on and have power to the coil that the cut off …is off. ? I have the Air cooled works extinguisher and cut off.
Depends how it’s been wired. Mine’s just wired to the coil +ve (to the ignition switch, effectively). If you’ve got an extinguisher (I haven’t) with contacts that activate when it goes off, makes sense to wire it through those.
I also have the solenoid wired to the coil. Dirt or wear in a Malpassi will mean a small trickle of fuel can leak through it. And same for needle valves in Weber carbs which dont like vibration .. My progressive slowed down eating fuel metering valves when I replaced the alternator and fan.. less vibration right next to the carb. on a T1. I have been through about 5 valves in 90000 miles.. The only downside to the solenoid is that you dont notice the leaking carb. valve until it floods to a stop at idle when you drop off somebody at the railway station a mile from home ..
