Water pump bolts - Yanmar 1GM10

[Wandering Star]

H,

would anyone know what size the small bolts holding the seawater pump to the engine block are? I’m not on the boat but need to ensure I have a small enough spanner or socket with me when I next visit - I’m guessing or 7mm?

Are they likely to be corroded or”fragile” to remove?

Thanks

 

[Tranona]

Can't remember exactly but they are an odd size in relation to the bolt size. Yes, almost certainly corroded. They are made of special Japanese cheese (mild steel), go through bronze and aluminium into cast iron - all in a location where you are likely to get seawater leaks! mine came out quite clean but the heads only just made it. Replaced of course and greased, plus ensuring no more leaks and lasted well for the last few years I had it.

 

[Gixer]

Try this thread.
Bolt for Yanmar 1GM10 water pump

 

[Wandering Star]

Thanks Tranona & thanks Gixer.