old 4hp twin cylinder merc

was given an old 4hp merc but cant find any useful info on it all i can tell you is that it is a twin cylinder Belgium with s/n 9189380 and a blue band anything would help as it doesnt run properly when its hot doesnt idle and water is not running threw in steady stream have replaced impeller info on how or where to get parts lists and some type of diagrams as would like to rebuild if possible. used to run like the clappers but had sat for a while and was never the same



found this site in another thread may help some one http://www.crowleymarine.com/parts.cfm

do a compression test first,to make sure your not wasting your time.both cylinder should be around 100 psi and at least 15 Psi of each other.If they are not then the motors cooked.If they are good then replace your impeller first,at least take it apart and make sure it in good shape.then pull the tell tale hose{pee hose} off the motor.Blow through it to make sure it doesn't have any thing growing or living in it. If its clogged run compressed air through it,If you don't have a compressor run some thin wire through to push whatevers in it out.also when you start the motor to see how shes working .If stream is still weak after that pull tell tale hose off motor while running a get a large paper clip put it in were the hose came off to see if any things stuck in there.I have to do this after every winter or sitting period living in florida.With all the bugs,mud dobbers n spiders critters.Then After you get the water situation fixed. Rebuild your carburator that most likely will fix the rough running.Good Luck.