Need a little advice

thereitisgone

Have a old yamaha autolube 2 stroke 50hp with trim and having little problem. When i accelerate the prop throws water up and at full speed its a lot of water, another problem i have is i think it has never given me enough trim if i dont have someone in the front of the boat.
My question is, the adjusting bar that the motor touches to stop it giving any more trim is already in the lowest hole but i see that the trim pistons go a good bit lower. Is it possible to remove that pin completely to give more trim. Or any other ideas.
I hope i have explained that correctly.

davlacey

sounds like the prop is to high in the water is it a shortshaft?

breghall

davlacey wrote: »

sounds like the prop is to high in the water is it a shortshaft?

i agree, maybe post a photo of the engine height, ideally your cavitation plate should be roughly level with the bottom of your hull.

I wouldn't worry about it throwing up water at full speed if it's trimmed out, if conditions are good and calm i'll throw water 6ft up when flat out..

You trim up/out so the pin in lowest hole is not an issue, you'll know if your trimmed out too much as the boat will start to porpoise (bounce) or you'll loose speed and rev up as the prop struggles to bite the water.

fergal.b

Yep some photos of it on the transom would be great, one showing the angle of the transom and one from the back showing where the cav plate is sitting.




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thereitisgone

Thanks for the replies will try and get some photos up as soon as possible.

thereitisgone

Sorry took a while to get pictures hope these work

fergal.b

That setup looks ok, I think you have one more hole you can use to bring the leg in closer to the transom if you need to. There are a few nicks out of the prop and these can also cause the prop to throw up water plus it may be why you are not getting the power to push the bow down.



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breghall

That set up does look to be fine as Fergal said. can't see how it's throwing up water when you accelerate as the boat should bury at the stern when powering off...are you sure it's always trimmed fully in when getting underway? if it's not then that wopuld lead to the throwing of water situation

Any chance of a vid to show us the prob in real time??

thereitisgone

I dont know why that last hole is there as i cant put the pin in there the hole is blocked. I have a a new prop which i used last year and still i had the problem, i put this old prop on at the end of last season just to see was the new prop the problem but its exactly the same.
Can i remove that pin completley and i would get a little more trim as you can see on the last picture there is more movement in the hydraulic ram or would it damage the ram if the whole force is on the ram and not sitting on the pin.
Cant get a video till i get it in the water, but to give you an idea its coming up and landing on top of the motor.

fergal.b

If it's coming up and landing on the motor I wonder could it be the transducer for the fish finder, it looks like it is fitted facing the wrong way so the flat edge could be causing the problem.

thereitisgone

You could be on to something there Fergal, i had everything of the back of the boat last year and i think this problem started after that. That fishfinder came with the boat and has never really worked and after i refitted it wrong it has been given even crazier readings. Am planning to put new one on this week anyway so hopefully get it into the water next weekend.
Hope that is the problem, many thanks everybody especially eagle eyed Fergal.
What do you think of that pin, can i remove that because i really think a little more trim would help and this trim problem i have had since i got the boat, had a experienced boat guy show me the ropes when i first got it and straight away he thought trim was bit strange too.

thereitisgone

Just had look at the boat 90% sure that is the problem Fergal, cant really see it clear in the pics but the tranducer is sticking down under the hull about an inch right in the biggest deepest tunnel in the hull and its perfectly angled to create the perfect ramp to shoot the water upwards onto the motor, many thanks again Fergal this has been driving me crazy.

fergal.b

You could try it without the pin but the engine might kick up in reverse and put strain on the ram. Have you somewhere in the bow that you could put a sandbag or a weight of some sort, in one of my boats I had a roll of builders lead





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fergal.b

thereitisgone wrote: »

Just had look at the boat 90% sure that is the problem Fergal, cant really see it clear in the pics but the tranducer is sticking down under the hull about an inch right in the biggest deepest tunnel in the hull and its perfectly angled to create the perfect ramp to shoot the water upwards onto the motor, many thanks again Fergal this has been driving me crazy.

:pac:

thereitisgone

There is a bow seat but stupidly its all sealed in , no storage space up there so the magic roll of builders lead wont help me. Last year started putting the fishing bag up there and over here all boats must have fire extinguisher so bag is quite heavy so must invent something to secure that and maybe line the bag with a lot of lead:D

thereitisgone

fergal.b wrote: »

:pac:

Thats brilliant

breghall

fergal.b wrote: »

If it's coming up and landing on the motor I wonder could it be the transducer for the fish finder, it looks like it is fitted facing the wrong way so the flat edge could be causing the problem.

Nice spot there Fergal.....

thereitsgone.... i honestly don't think you have any issue with the trim, in the pics your engine is pretty much straight and at the correct height for getting under way. When you trim the engine goes up , even higher than it is now, that pin is doing nothing but will only make the engine trim in a tiny bit more..I am sure that the pin is not your problem.... as you'll trim up when under way and the engine will move away from that pin... If you are having trouble with the handling of the boat with that engine then is it possible that the engine is too big for the boat??? Does the boat "bounce" a lot when you're put in it?

thereitisgone

Yes it is more than possible that the engine is to heavy for the boat, its a yamarin 4.3 metre double hulled boat it is heavy, but i have only seen maximum 40 hp on this model over here.
Its not so big problem if i have someone in the bow its perfect,it does bounce a lot when at top speed zig zagging a little cures it, so it looks like lead lined fishing bag is the way to go. Thanks Breghall think you might have solved my second mystery.

thereitisgone

Ok, so more advice needed from you kind folks. Motor i believe is oversized and too heavy, was in boat shop today and noticed they are selling outboard hydrofoils, have been googling these for past hour and seems it could solve problem lifting the back of boat a little more but sounds like a lot of people think they could be bad maybe even dangerous, what are your thoughts on these and has anyone ever needed to fit them and what were the results.

breghall

they work on some boats and not on others... i've never been a fan as I find them a bit nuts when turning at speed. Friends swear by them so i guess it's personal choice. Try find someone with them on a boat like yours if you can, and see how it handles for them

fergal.b

I personally don't like them or the fact that you have to drill holes in your outboard to put them on and that they put extra stress on it, I also don't like buying secondhand outboards that have holes in them if they were any good the outboard companies would have them built on as they spend millions on designing their engines. I would be more worried about the fact that the outboard is too heavy for your transom and the damage that may cause :eek: If you are going to to stay with that engine have a look at electrical or mechanical trim tabs and think about reinforcing the transom.



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