jan.bauwmans wrote: ↑Sun Nov 05, 2023 12:42 am
How you can easily check for vacuum leaks ?
A common way to look for vacuum leaks is to spray brake cleaner on the carbs and around their bases. You'll hear a change in RPM if the engine draws in those fumes. The brake cleaner dries without residue, BTW.
Check the vacuum hose that goes to the brake booster. Disconnect it at the engine, and cap it to see if the idle RPM changes. Same for the vacuum hose that goes to the distributor.
Another, but harder to check, possible vacuum leak location is the crossover hose between the front and rear carbs. It's under the air-shroud sheet metal, so not as friendly to check. And then there's the intake gaskets, but we're getting further down the path of unlikely causes.
And, always, look at your spark plugs. That's the classic way to judge lean-versus-rich mixtures.