How often do you change your ob impeller?

firstascent2002

New member
Joined
12 Jan 2004
Messages
567
Location
Exeter
Visit site
My 3.3 has a 5 year old impeller. Still pumps water well...the "book of words" says to change it at every service every year...what do other people do?

J
 

VicS

Well-known member
Joined
13 Jul 2002
Messages
48,334
Visit site
I suspect very few people change them annually.

After five years its worth keeping a good eye on the pee stream. Or changing it anyway.

Left for too long there is a risk that a vane or two could break off and block the cooling system! :mad:

If the water pump is located behind the prop ( but that can only be so in fixed drive models) there is no excuse for not changing it regularly.

How often do you change the impeller in the seawater pump of an inboard engine?
 
C

catalac08

Guest
My main engine, a Tohatsu 30hp changed impeller after 3 years/300hrs and there were faint cracks starting to develop at the root of the vanes on the impeller. Changed then after 2 more years 2yrs/200 hrs and impeller looked immaculate. Had a 3.5 tohatsu for tender and not changed in 5 years but probably only 50hrs total usage. Had a 2hp Yamaha for 12 years and never changed impeller. I think if outboard is your main engine it is important not to fail so I think every 2 years/200hrs is prudent perhaps stretching to 4 years if you do less than 80 hrs per year. I suppose type of usage is also relevant i.e. if engine is often flat out then that will create more wear and reason to change more often.
 

greenalien

New member
Joined
11 Jun 2010
Messages
700
Location
Southampton
Visit site
The problem with most small outboards is that the internal fastenings , unless removed and greased regularly, will seize up.
A simple job like changing an impeller then becomes a nightmare of broken studs and, if you're really unlucky, a broken water feed pipe ('cos it will have seized in the impeller housing and instead of sliding free, will pull out of the cylinder head instead).
While ignoring the need for regular servicing is something you can probably get away with for a few years, it's a false economy in the long run.
 

ghostlymoron

Well-known member
Joined
9 Apr 2005
Messages
9,889
Location
Shropshire
Visit site
I've never changed the impellor on my British Seagull Featherweight. I believe it is the original from 1965. If it was a rubber one, I'd look at it every 3yrs or so.
 

DownWest

Well-known member
Joined
25 Dec 2007
Messages
13,192
Location
S.W. France
Visit site
Yeh, Seagulls are a special case.
On a Suzuki 6 the problem was finding one around here. A mail order outfit in Bury st Edmunds kept me waiting (after debiting my card) before admiting they couldn't find one. Three French sites came up with nothing, so I was reduced to calling every service agent in the Yellow pages. Worked in the end.
 

Blue Fox

Member
Joined
28 Mar 2005
Messages
183
Location
Muiderberg, The Netherlands
Visit site
Don't wait to long changing the impellor! My 6 hp Yamaha seized suddenly after becoming quite hot - impellor broken, couldn't move anything. My mechanic said I was lucky he was able to get the cylinders going again.
 

PeterGibbs

New member
Joined
3 Sep 2001
Messages
2,113
Location
N London, and boat in Suffolk
Visit site
My 3.3 has a 5 year old impeller. Still pumps water well...the "book of words" says to change it at every service every year...what do other people do?

J

Take it out and examine it closely:

Are there any signs of fracture at the root of the blades? Both sides.

Are there any parts missing from any blade?

Is there any sign of disconnection between the metal hub and the "rubber" blade structure?

If all good, put it in your spare box, and put in a new. No one should excpect an impeller to be 100% reliable at 5 years - I submit. Really not worth the hassle.

PWG
 
Top