no worries. make sure you put a strip of rubber over the exhaust port and re tighten the exhaust to get a decent seal. .test pressure( pump up) first before you test with suction as if the crank seals have gone you can pull the worn seals back onto the crank and give a false test. 0.5 bar is the highest pressure to use, any higher and you risk damaging good seals.it should hold pressure for a reasonable time if you do have a leak it will be evident straight away.then use a pump spray with washing liquid solution.
if your mate has the stihl pressure tester it will come with all the necessary blanking plates.GOOD LUCK |