martynwhiteley
Well-Known Member
I recently purchased a Birchwood 27 with twin BMW B130 petrols on legs.
Despite a new Johnson pump and hoses on one engine, a new impellor on the other and many hours bent double in a micro sized engine room, they are both very reluctant to prime and pump raw water.
The inlet comes from the leg, through a vetus strainer, and then the direct drive Johnson pump on the end of the cam. The boat had been out of the water unused for a few months.
After suspecting a blocked inlet, I tried pumping from a bucket in the bilge. The new pump did prime eventually at about 5000 rpm, but fails to repeat this very often when reconnected to the leg inlet. However water will flow back out from the strainer through the leg inlet ok. There does not appear to be any air leaks.
The other engine ran ok for a couple of hours, but now struggles to prime.
Any advice?
Also, could the leg inlet be replaced by sea-cocks or would this affect leg cooling?
Plus, could some back pressure in the system be causing the problem?
Please save my sanity!
Despite a new Johnson pump and hoses on one engine, a new impellor on the other and many hours bent double in a micro sized engine room, they are both very reluctant to prime and pump raw water.
The inlet comes from the leg, through a vetus strainer, and then the direct drive Johnson pump on the end of the cam. The boat had been out of the water unused for a few months.
After suspecting a blocked inlet, I tried pumping from a bucket in the bilge. The new pump did prime eventually at about 5000 rpm, but fails to repeat this very often when reconnected to the leg inlet. However water will flow back out from the strainer through the leg inlet ok. There does not appear to be any air leaks.
The other engine ran ok for a couple of hours, but now struggles to prime.
Any advice?
Also, could the leg inlet be replaced by sea-cocks or would this affect leg cooling?
Plus, could some back pressure in the system be causing the problem?
Please save my sanity!
