YSE8 Mount Problem

[barnaclephill]

mounting issues

...2" or so higher than the front ones, is there a sensible reason for this or is it just to make building engine bearers as awkward as possible? Is there any reason I should not make a couple of mounts that would place the rear at the same level as the front and save a considerable amount of trouble?

I have a YSM8 which is similar to yours in the photo. Two reasons in my (35 y.o.) installation manual are 1. the angle to get the prop shaft out of the hull and into deep water, with keel considerations, etc and 2. the need to keep the engine at a certain level to which the designers designed for lubrication purposes. I have seen this diagram in the installation manual and could retrieve it if needed (by Saturday).

I can fully understand your budgetary constraints, and that you have already bought the engine. Other options could have been cutting an outboard motor well, or installing a brand new Chinese diesel, marinised yacht engine or stationary engine for a good price (i.e. 10HP stationary engine, $650 here; or yacht eng for imported direct, less than $3000 here).

Your rear mounts in the photo could be modified to level with welding some infilling brackets or solid timber pads, to make it easier to mount to your bearers, and then after that they will need this level/angle manipulation to line up with lubrication & stern gear.
My engine is on steel bearers and plate steel pads, in a steel boat, so echoes very badly.

 

[l'escargot]

Sorry have just looked again, they would be pointing down through the bottom of the keel, in any case the downward angle would be more than the 15 degrees permitted for the YSE8. I am taking the prop shaft to the boat tomorrow and am going to do some fidling to see before taking any action with the mounts.

john

I'm not sure it would be greater than 15 degrees from that picture. Try putting similar height wooden blocks under the front mount plates as well and measure the angle of the engine. There will be scope for varying the angle by using the adjusting nuts on the engine mounts or using shims if you need greater adjustment.

 

[johnjfrake]

Once again thanks for the inputs, I will be on boat for a couple of days today (she is in the water currently) and am going to go into the deep dark places under the lazarette and see just what angle the prop shaft/engine must be installed at! Feed back will come later.

john

 

[Keith 66]

The only good thing about those engines is they were reliable. Apart from that they are heavy, hideously noisy & vibrate badly at low revs. I expect the savings you make will have to be spent on dental treatment as all your fillings are liable to fall out.

 

[Tranona]

Once again thanks for the inputs, I will be on boat for a couple of days today (she is in the water currently) and am going to go into the deep dark places under the lazarette and see just what angle the prop shaft/engine must be installed at! Feed back will come later.

john

Is the stern tube fitted already? If it is then that determines the angle of the engine and is the fixed datum point to build the bearers (if these are not already fitted). If there is no stern tube, not only do you have a major job fitting one, but you will have to decide on the angle to ensure that you have enough vertical clearance for the engine, and that you keep within the maximum angle for the engine, usually 15 degrees.

 

[johnjfrake]

The dental treatment I'll take my chance on, it'll probably shake my last few brain cells out my ears as well.

No the stern tube isn't installed, the tube, prop shaft and prop came with the engine as did all the controls. I intend to build a mockup of the engine and see where that takes me.

Once again thanks for the inputs!

John

 

[johnjfrake]

Incidentally a friend of mine has a boat fitted with one of the later model Yanmars and much the same is reported of them. Should this engine not prove satisfactory then I'll jus have to save up for a twin cylinder and a new prop. meanwhile the fuel tank, filters, engine beds (if designed with care) stern tube and prop shaft should all be re-usable. The controls are a pain cos yse8 controls appear to be a little singular so will have to build the potential to change into my thinking.

john

 

[sailorman]

Incidentally a friend of mine has a boat fitted with one of the later model Yanmars and much the same is reported of them. Should this engine not prove satisfactory then I'll jus have to save up for a twin cylinder and a new prop. meanwhile the fuel tank, filters, engine beds (if designed with care) stern tube and prop shaft should all be re-usable. The controls are a pain cos yse8 controls appear to be a little singular so will have to build the potential to change into my thinking.

john

the engine feet are wide apart compared to modern engines this reduces oscillation cycles BUT you must have the correct mounts. too soft & it will shake the coach roof

 

[johnjfrake]

Thought I would post this last photo of the side view after modifying the rear engine mounts to be at the same height as the front ones. This give me two options for fitting the beast. Once again thanks for all the advice, may visit this one again from time to time as progress is made!

 

[paws]

I've only just seen this thread, so my comments may be a little late.... However....
I had a YSE 8 in my Snapdragon 747 and it proved totally satisfactory during the time I had it (approximately 15 years), it never missed a beat, gave just over 5 kts in still water (with a clean bottom) and would run for about 3.6 to 3.8 hours at 87% revs on a gallon of diesel.

My engine was not noisy and didn't suffer from excessive vibration, the altenator was excellent providing a good output, and the engine was easy to hand start using the geared manual starting system for the occasions when in foreign ports for too long, I had used up the power in the battery...!

The secret to avoiding noise and vibration is often in the correct fitting of the engine and I found the standard Yanmar, "steel bonded to hard rubber engine mounts" that were fitted as original equipment by Thames Marine, to be ideal. My boat was also fitted with substantial bonded in GRP over wood engine mounts and no doubt these also helped. I had a fairly common 12 X 8 three bladed propeller that didn't do too much to hinder the performance under sail, but provided good solid thrust when the going got tough.

The engine helped me cruise extensively across the channel from the south coast of England to the French, Belgium and Dutch coasts, with trips to the Channel Islands and Brittany....a very reliable, quiet, economical, and well put together engine that served me well.

I recommend the steel to rubber bonded engine mounts coupled with substantial bearers, as these can make a huge difference.

 

[johnjfrake]

Thanks for your interest and advice. I have just finished the model/template of the diesel tank and am about to get some quotes for that! Engine bearers are next, laminated form good grade marine ply and then bonded in with epoxy grp.

Regards

john