Reviving Old Yamaha Engine
Gday fishos ill start off with this is a great forum and awesome community so looking forward to contributing more. Basically we have a 1990 yamaha 40 HP 4-stroke from my grandfather and me and dad are in the process of trying to get it up and running again so ive got a few questions so bear with me.
So the engine hasnt been run in around 10 years (only have an idea) most of which has been in our garage. Aside from a bit of surface rust on the exterior it seems to be in pretty good condition but this is just looking on the outside. Dad has already removed the carbs and taken them apart to check their condition and they were looking pretty sweet execpet for a few seals which we have already replaced. Thermostat was buggered, spark plugs need replacing and we've just removed the lower leg so we can replace the water pump and we have the parts for all that on the way. If ive missed any other details let me know. Ill put some pictures in on the exterior of the engine.
So here's where we need some help (see pictures below the question if it helps)
We have basically no experience in terms of prepping an engine after this amount of time of not being used or boat engines to begin with so what other things should we be looking at to make sure its good to go or even if it will start at all? Done some research for replacing fuel lines but any other info would be a big help
As i said thermostat was buggered and there's still lots of crap from where it was, whats the best way to clean this out?
One of the other issues with the motor is the tilt as seized from rust. Any ideas on how we can fix this or are we better off replacing whatever parts need replacing? 
Also near the water pump under the damper seal (just going off diagrams online) the metal looks like its been pretty corroded will this be an issues later on even after the seal is replaced?
Last question is when we removed the lower leg there was quite a lot of oil around the water pump. We arent sure if this is normal or because we had the engine on its side for a while or if there might be a leak somewhere. Any idea which it could be and if its a leak where it might be from? In the above picture the water block was completely full of oil which we wiped out.
Asking a lot but basically any info on the questions ive asked or other things that i havent mentioned would be really appreciated
Cheers and tight lines.
shortfuse
Posts: 211
Date Joined: 02/01/12
Looks like a 2 stroke to me
Looks like a 2 stroke to me
squidvicious1
Posts: 824
Date Joined: 22/07/10
Start with its a 3 cylinder
Start with its a 3 cylinder 2stroke,as by the oil tank and flat head with no valves overhead.youre doing well so far by pulling the motor apart and understanding the basics.Products like saltaway will remove the corrosion to a degree.
Get a owners manuel and take the motor to a Yamaha mechanic and discuss what parts are needed and what you can do about the tilt yourself. Might pay to ring first as they may be busy after the break.
Hope that helps.good luck.that model is a very good one with having 3 cylinders balances itself better than a 2 cyl.
Tbox
Posts: 9
Date Joined: 13/12/17
Yeah you're right its a 2
Yeah you're right its a 2 stroke. Thanks for the advice
Bazooked
Posts: 151
Date Joined: 18/10/12
give boat city a call,
give boat city a call, experts on yammys
Darren253
Posts: 570
Date Joined: 23/07/16
This Guy
www.youtube.com/watch
His range of videos should answer pretty much all of your questions above! Tons of information especially for older style outboards
Faulkner Family
Posts: 18023
Date Joined: 11/03/08
your doing the right thing
your doing the right thing by doing the research as you go. little by little you will get there. never done an outboard but have done car engines before. patience is a virtue when it comes to these kind of things. as Squidvicious said get a bit of advice from thse in the know. a bit of knowledge can go a long way
RUSS and SANDY. A family that fishes together stays together
scano
Posts: 1247
Date Joined: 31/05/07
You do know
That the tilt of the engine is via the small lever below the front of the engine cowling? Near where the remote steering arm connects.
I say this because it is unlikely that a manual tilt motor would have its tilt ceased from simply sitting in the shed.
It it is a small basic spring loaded lever that locks the motor in position. Where abouts are you located? Happy to come and take a look mid week after work if that helps? (Perth metro)
i got a small 2 stroke yammie myself. Not all that difficult one you learn what’s what.
Tbox
Posts: 9
Date Joined: 13/12/17
Both levers and all the
Both levers and all the speings work for the tilt but axel it sits on (not sure what its called) is rusted and looks to be why its siezed we think. Thanks for the offer, might take you up on it but we are taking it in this week to see idlf we can get some snapper bolts removed.
shortfuse
Posts: 211
Date Joined: 02/01/12
Before you get too far into
Before you get too far into it, do you have the forward control set for it? Doesn't look to be a tiller steer version. Maybe wasting money if you have to add on the cost of forward control set or convert it to tiller steer, it will all add up
Tbox
Posts: 9
Date Joined: 13/12/17
Yeah its just disconnected
Yeah its just disconnected right now to make thinhs easier
cruzy111
Posts: 274
Date Joined: 08/10/13
Have a sniff of the oil in
Have a sniff of the oil in the water pump. If its gear oil or 2 stroke oil. If its gear oil you will need to replace the gearbox oil seals. When you first run it use premix 50/1 fuel the oil injection may not work.
Tbox
Posts: 9
Date Joined: 13/12/17
How can you tell the
How can you tell the difference?
cruzy111
Posts: 274
Date Joined: 08/10/13
You should change the gear
You should change the gear oil anyway. Drop it out and see if it is the same oil. You will need a good big screwdriver to loosen the filler and drain screws. You may need to tap the screwdriver with a hammer they can bind on the seal. Gear oil stinks. 2 stroke oil stinks as well but has a distinct ammonia or similar smell and is sometimes blue in colour.
Brock O
Posts: 3222
Date Joined: 11/01/08
Just a thought would be to
Just a thought would be to pull the heads off, youll need to order new head and cover gaskets and have a manual and torque wrench to put back on..two stroke heads easy...good to look at deflectors and clean water ways as good to clean and inspect.
This was an issue with early model Johnsons, water galleys and especially deflectors.
Tbox
Posts: 9
Date Joined: 13/12/17
Cheers Brock O will
Cheers Brock O will definatly look into it
Brock O
Posts: 3222
Date Joined: 11/01/08
Remember the CRC or
Remember the CRC or inox...nice and easy on the bolts..