jfkal
Active member
My new Yanmar 3GM30 finally arrived.Now I need to "extract" the old und put in the new. Any handy ideas? Boat is a Jeanneau Sunshine with the engine located under the companionway steps.
DIY Engine Change
- Thread starter jfkal
- Start date
vyv_cox
Well-known member
There are books and three-issue articles written on this, so don't expect a comprehensive description here.
The main issue is to get the alignment and position of the new engine drive coupling to match the old one. You can make drawings of the mounting arrangements of both and try to determine what height change is required. Or you can just dangle the new one and work it out that way. Make up spacers in rough wood first and ensure everything is OK. After that, when everything fits, make a permanent set. When everything is set up, the shaft is central in the stern tube with the prop in the right place (and rotating in the right direction) it's just plumbing and wiring. Well, almost.
The main issue is to get the alignment and position of the new engine drive coupling to match the old one. You can make drawings of the mounting arrangements of both and try to determine what height change is required. Or you can just dangle the new one and work it out that way. Make up spacers in rough wood first and ensure everything is OK. After that, when everything fits, make a permanent set. When everything is set up, the shaft is central in the stern tube with the prop in the right place (and rotating in the right direction) it's just plumbing and wiring. Well, almost.
Trevor_swfyc
New member
reversing forward
Somebody I know fitted a new engine last year and decided to fit a new prop as well. When I launched him and he applied reverse the boat went forward. The engine was driving the gear box the other way even though the engine was the same make as the old one. He then had to buy another prop to overcome the problem evidently this was the easiest solution.
Its all a worry!
Trevor
Somebody I know fitted a new engine last year and decided to fit a new prop as well. When I launched him and he applied reverse the boat went forward. The engine was driving the gear box the other way even though the engine was the same make as the old one. He then had to buy another prop to overcome the problem evidently this was the easiest solution.
Its all a worry!
Trevor
Caronia
New member
My favoured strategy would be to stand around looking pitiful and helpless until somebody who knows what they are doing takes pity.
Strathglass
New member
Re: reversing forward
On my boat with a PRM hydraulic box it is only the morse cable on the fwd/rev which requires to be altered to reverse direction of drive. Not all gearboxes are so simple however.
Iain
On my boat with a PRM hydraulic box it is only the morse cable on the fwd/rev which requires to be altered to reverse direction of drive. Not all gearboxes are so simple however.
Iain
kgi
New member
some times the hardest part is removing the engine without wrecking the rest of the boat in the process.........keith
Buck
New member
Your going to need a strong enough engine lift and someway of supporting it, if you put it in the cockpit then odds are it will go through the sole when the weight of the engine is on it, some people use chains to attach the engine to the lift but I have used webbing straps before.
Buck
Relax, life is just a game.
Buck
Relax, life is just a game.
yoda
Well-known member
Well for starters you have probably worked out these things are not light weight. First you will need to disconnect and lable up all the fixings. Decide if they are common to the new engine (is it the same model as the old one?) clean up the engine space as it's the best opertunity you will get and then start on ensuring the bearers are the correct height and width. Having done this crane out old unit, and in the new one. Then the fun starts getting it positioned and aligned. Follow the book! Once there start to reconnect, and re-run water, fuel, battery leads, control loom and exhaust. Check book for type and size of prop or refer to a prop manufacturers site for guidance. Once all this is done you are ready for a first run however you will need to ensure suitable arrangements (temporary) are in place for the cooling water. It's surprising how much water that little pump can shift. A dustbin collecting it from the exhaust and a long hose back to the pump suction with a hose for make up as required works well. Any more ? please send a pm
Yoda
ps It isn't that bad just time consuming. Mine took 2 days and wasn't straight forward but the engine was light enough to move by hand. Yours won't be.
Yoda
ps It isn't that bad just time consuming. Mine took 2 days and wasn't straight forward but the engine was light enough to move by hand. Yours won't be.
kgi
New member
Do not forget to chock&block the propeller shaft to stop it from dropping, if there was little or know vibration with the old engine chances are its alright, oh one other thing put a hose clamp round the shaft snug up against the stuffing box, if you have a PSS type system disregard this bit, but it stops the shaft moving backwards when you "wrestle" the engine onto its bed......and for christ sake don't forget to take it off !!!!!!!!...........keith
jonlaw
New member
Listen to Trevor !
Make sure the engine output direction matches your old one. Our 3GM30 didn't and we only found out after 2 years that the fitter had linked our controls so that when we selected forward, it actually put the gearbox in astern!
Also, do your self a favour, when the old engine is out, ensure that the engine compartment is SPARKLING WHITE before fitting the new.
Because from then on, every time you take a 'look' the slightest oil leak, exhaust leak, coolant leak, etc is so obvious that you fix it and also clean it up so that further 'tell tales' are quite evident .
Make sure the engine output direction matches your old one. Our 3GM30 didn't and we only found out after 2 years that the fitter had linked our controls so that when we selected forward, it actually put the gearbox in astern!
Also, do your self a favour, when the old engine is out, ensure that the engine compartment is SPARKLING WHITE before fitting the new.
Because from then on, every time you take a 'look' the slightest oil leak, exhaust leak, coolant leak, etc is so obvious that you fix it and also clean it up so that further 'tell tales' are quite evident .
jfkal
Active member
Tried that. Nobody came.
Intend to use the mainsheet gear to lift it out. However it would not attach straight down to the engine hooks but "angle" around the companionway steps.
Any ideas?
Joerg
Intend to use the mainsheet gear to lift it out. However it would not attach straight down to the engine hooks but "angle" around the companionway steps.
Any ideas?
Joerg
salamicollie
New member
Just finished an engine change from a YSB12 to a 2GM20 -
1. Getting the old one out - strip the ancilliaries (alternator, starter cables etc) disconnect the prop shaft and drain the engine of oil and water to lighten the load. Easy it forward on the beds (wrecking bar and 2 strong blokes) onto something to spread the load. I used a chain hoist and gallows borrowed from the yard for the final lift - but a mainsheet will be OK if in good condition.
2. Getting the new one in - as suggested above clean, degrease and paint first, then make a jig out of plywood or MDF from the dimensions on the drawings at Yanmar.com and fit the Engine mounts to this (PM me if you need more info) - this will let you see if you need to change the engine bearers etc.
Then reverse process to get new one in (2 blokes wrecking bar and packing to protect the hull)
3. Then try to reconnect all the cables and fuel lines finding tha all the positions have changed slightly....
1. Getting the old one out - strip the ancilliaries (alternator, starter cables etc) disconnect the prop shaft and drain the engine of oil and water to lighten the load. Easy it forward on the beds (wrecking bar and 2 strong blokes) onto something to spread the load. I used a chain hoist and gallows borrowed from the yard for the final lift - but a mainsheet will be OK if in good condition.
2. Getting the new one in - as suggested above clean, degrease and paint first, then make a jig out of plywood or MDF from the dimensions on the drawings at Yanmar.com and fit the Engine mounts to this (PM me if you need more info) - this will let you see if you need to change the engine bearers etc.
Then reverse process to get new one in (2 blokes wrecking bar and packing to protect the hull)
3. Then try to reconnect all the cables and fuel lines finding tha all the positions have changed slightly....
jax
New member
Make your job easier by striping the old engine in situ, remove the flywheel and everything you can, much easier to haul out then with aid of block off the boom. ENJOY!
