Merc Outboard Problem

SteveA

Active member
Joined
31 Dec 2001
Messages
490
Location
Cumbria. UK
Visit site
I have an old 25hp Merc outboard which has given good service up to now, sorry to say yesterday, from having a good jet of water coming from the tell tail, now there's none. Luckily someone noticed as it stopped flowing and we cut the engine straight away, so no overheating.
Although I've not started on it yet what tips are there to try and get the bolts moving to take the bottom section of the leg off.
Also when or if I get these off is there anything else to disconnect before drawing this section off - how does the gear change linkage connect for example?
I've an idea that the impellor has given up - any other ideas?
 

aztec

Active member
Joined
10 Oct 2001
Messages
2,522
Location
Poole Dorset
Visit site
the gear actuation rod is splined so should come apart fairly easily, there's a bolt/nut under the anode/fin on the cavitation plate.. so don't forget that one. i seem to remember put it into reverse (ok... astern!) to reasemble.. from memory it's easier to get it alighned.

one tip i remember using is if the bolts are tight due to corrosion, don't force them... plenty of plus gas, and "rock" the bolt as you're undoing it.

but before you do, check all the other bits, there's a hose coming from the powerhead that goes out thu' the casing. this gets blocked easily, take it off and have a look. the thermostat is under a cover held by two set screws, under this is a rubber diaphagm, make sure that all is ok there, as any leak effects the high tension side.

hope this helps. steve.
 

SteveA

Active member
Joined
31 Dec 2001
Messages
490
Location
Cumbria. UK
Visit site
Steve,

Thanks for the tips.

I've been able to remove the bolts but looking at them i think that I'll have to fit helicoils(all of them were quite loose). Interestingly, the anode/fin is held on by a bolts from the top.

The lower casing has dropped about 2" so from what you say I think I'll try wedges to break the splines free.

Steve.
 
Top