This beautiful CBR250RR MC19 had been standing for a long time, wanted to spin for a while and then it was done.
Carburettors weren't very dirty so I cleaned everything manually. After installation and starting of the engine, cyl. 2 only 50 degrees.
Spark plug was also broken but a new one did not improve. So the problem had to be in the carburetor. So disassembled for the second time and cleaned carb 2 extra.
The problem remained. Then it was cleaned extra intensively by ultrasonics. Many openings turned out to be stubbornly clogged. This took a lot of extra time.
It also turned out that the float level was not good (was too rich) and the idle jets were made wider (never do this!!) than desired.
Adjusted float level and 4 new idle jets. After the ultrasonic bath, rebuild the carburettor and put it back (first a leak test)
Starting and ..... running poorly, now cylinder 4 did not get very hot. Put in a new spark plug and the problem was solved. Had been running too rich all this time and that's bad for a spark plug. So it was broken.
Synchronized, then a little fine-tuning with the pilot screws and this MC19 runs again very nice.
Music: Royalty free Epic Heroic musuc (for video's)
Terminus by
Scott Buckley