Note:If you use the Yamaha Seal(Part No:11H-12438-10-00) the glue they use is harder so heat underneath the metal cup until it sizzles and be careful and don't force it
Note the 10mm thrust washer painted red here.some times by age it's welded to the cam shaft and you cannot see it.
Important! It MUST be there and also if it is there you do NOT want to place another one on top of it!!!
1:Place washing up bowl under Radiator.
2:Drop Coolant
3:Remove Radiator
4:Turn Cooling fan to access and remove the Left and Right 10mm cylinder Jacket bleed bolts and allow to drain into washing bowl.Replace bolts after draining now!!!!(Requires 10mm socket with ratchet extension).
5:Remove cooling pipe.Note.Rubber o-ring on cooling pipe should be,"In-the Groove".Use cheap silicone sealer on re-fit.
Silicone Sealer
6:Remove Seat and tank.
7:Remove Large rear Engine Hanger/Frame bolt.
8:Remove the two smaller rear hanger bracket bolts and slack off the front rear hanger bolt so you can swing the Bracket along with the coils up and out of the way.
9:Remove Carb inlet bolts and slack off the inlet boot locking rings etc so you can maneuver the carbs out of the way and rest them on top of the frame.
10:Remove the Water pump cover bolts and pull the Small rubber pipe off the back of the Water pump cover.
11:Prise off the Water pump cover.
12:Remove impeller taking note of the 10mm thrust washer that,"MUST" be on the end of the Cam-shaft when you re-fit the assembly and the copper,"Crush" washer that goes beneath the 10mm domed nut that holds the impeller on
13:Pull off any way you can the Synthetic Spring loaded rubber boot.This is the part of the system that most commonly fails and cause the weeping coolant leak.
14:With a small blunt screwdriver clean the area inside the metal cup of debris.Brake/Carb cleaner should be at hand as it's the best for de-greasing/cleaning and use liberally inside the up and dry off with tissue(I use toilet roll).
15:Remove the spring loaded Boot part from a new Mech Seal.This should be done carefully so as not to tear the boot.If you apply a little pressure to the boot to try and force it out whilst playing some heat to the under side of the metal cup(I used my cigarette lighter)this softens the sealant they use to bond the boot to the cup and it should come free.
16:Smear a medium amount of silicone gasket sealer onto the bottom of the Rubber boot.
17:Insert boot into cup taking into account the protruding Metal lugs of the Metal part of the Mechanical seal e.g orientate correctly when fitting the boot.
18:Press new boot a few times into the cup to make sure it compresses and releases freely around the lugs.
You can now re-assemble the water pump as normal.Smear some washing up liquid on the Ceramic Washer(Polo Mint) before you do and push a pin through the weep hole to make sure it's clear before you re-assemble.DON'T forget the 10mm THRUST WASHER that goes on the end of the cam-shaft!!!!! and the copper Crush Washer.
Extras:"Davy" are an Australian company who make irrigation pumps.Because of an obscure post I found on the Internet and contacting an Australian Guy called,"Buff7454" on an Australian Forum.He told me and sent me some of these Mechanical seals at around a 5th of the cost of what my local Honda dealer wanted!!
They are the same seals.There was no UK link/contact where I could get them."Davy" do supply them in Australia(of course) and from my research the USA.
Also these can be used,
