New Suzuki 150 challenges

[brucehawsker]

Transom length is 570mm measured really carefully from bottom of the cutout to the bottom of the V.

Shaft length see earlier post by Charliee is apparently 635mm. It does look as though it is an XL.

The bottom of the cav plate is mounted pretty well exactly in line with the bottom of the V.

I am going to hopefully take her out later today and take photos from within the boat at test and at speed.

[neil.mccrirrick]

Standard shaft lengths are 15, 20 and 25. Sometimes referred to as standard long and extra long. At a 22 inch transom you could go either way I guess. My transom is 23 and I went long shaft as on a bracket you can alter the angle so the cav plate can sit higher. I would still talk to the rib manufacturer but my guess is you have an extra long shaft on and should have long imho

[Xk59D]

outboard looks too low as said previously, i wouldn't use it again until you speak to the dealer.

remember you need to measure vertical, not on the angle of transom though.

as your old engine was a long shaft and i assume you were happy with it that is what you should have on it again imo.

[charliee]

If it was me I would not use it until matters have been discussed with the supplier, IMHO you've been supplied with the wrong engine end of, as others have said you should start at 1 inch above the the line of the hull and maybe go higher. As it is the engine already looks too high, furthermore you already have issues with raising the engine and need to adapt the A frame.
Looking at the close up photo of the engine bracket it looks like the paint has chipped from the lowest hole (on the left side) indicating that the rigger may have tried this location first and for what ever reason decided not to use it.

[Last Tango]

Originally Posted by brucehawsker

Transom length is 570mm measured really carefully from bottom of the cutout to the bottom of the V.

Shaft length see earlier post by Charliee is apparently 635mm. It does look as though it is an XL.

The bottom of the cav plate is mounted pretty well exactly in line with the bottom of the V.

I am going to hopefully take her out later today and take photos from within the boat at test and at speed.

Can you also measure the distance from the top of your transom up to the horizontal parts of the mounting bracket to see, theoretically, how much lower the engine could be dropped. My thought being, if it's any more than 4" (100mm) then a "L" shaft engine is what you need. ie Would loosing 4" off the top and 1" off the bottom put you in a better place?

"Ditto" the comments regards using it. I wouldn't.

[jwalker]

Originally Posted by brucehawsker

Transom length is 570mm measured really carefully from bottom of the cutout to the bottom of the V.

Shaft length see earlier post by Charliee is apparently 635mm. It does look as though it is an XL.

The bottom of the cav plate is mounted pretty well exactly in line with the bottom of the V.

Bruce, that's exactly as it should be and you're not going to get it better by changing shaft length.

These folks telling you to get a shorter shaft can't do their arithmetic.

Also, they don't seem to understand that keeping the props in the water as much as possible will give you best overall performance.

Watch this video and note that, with the exception of when the boat actually leaves the water completely because of its speed, the drive is low enough to to keep propelling the boat, even when the hull is out of the water. The requirement is that the section of the hull rear of the bow is the running surface and if possible the hull should run and land on that.

https://www.youtube.com/watch?v=DH459_enBw8

If you go the route of lifting the engine too far, which a shorter shaft will force you to do, when your hull leaves the water you will also loose forward drive and the hull will be dead stick until it lands and the prop has time to regrip the water. During this time you will be at the mercy of the hull angle and the type of wave it lands on - it is effectively out of your control during that time. This will give you a seriously uncomfortable ride in the Solent chop. On the same tack, a propeller which can run partially surfaced without loosing grip will also help considerably in keeping the drive on giving you best performance and best ride.

Since your boat is a rib, much of its safety relies on the bow being high giving you advanced handling in following seas and steep seas. Keeping your engine low, provided it's within an acceptable range, which your is, will give you the maximum leverage at the transom to lift the bow by applying throttle so enhancing your ability to keep making progress when others are struggling.

Stick with it and learn your new engine is my advice.

It's unfortunate that the clearance with your A-frame is a nuisance but that can be resolved. And if you resolve that, you still have the ability to lift the engine one more hole should you feel it's necessary.

Go and use it and enjoy your new power.

[Xk59D]

What a lot of nonsense.....

Wrong engine end of discussion

[jwalker]

Originally Posted by Xk59D

What a lot of nonsense.....

Wrong engine end of discussion

Whatever...

[Xk59D]

Old engine was a long shaft and looks to be sitting maybe 1" above the transom so even a long shaft wasn't needing the saddle sitting on the transom to get the performance he had previously/prop deep enough. So absolutely worst case is put a long shaft Suzuki on the transom and it will be lower than what he has ever had and it gives the ability to go up if need be....no more splashing and no more hitting A frame.

You could make the current engine work but it is obvious the engine needs to go up, going down may get rid of splashing but is hiding it, not fixing it. The only way to make that engine work properly on that rib is to get a new transom put on and drill new holes in correct place (higher up)....and modify the A frame since engine will be higher than a heroin addict.

[charliee]

The issue is the new engine appears to be mounted too high already, this has been done to get the cavitation plate more or less level with the hull. The engine is mounted so high on the transom because the leg of the engine is too long. In order to get a sensible position on the transom it means that the engine can't be trimmed up.
Everything points to the wrong engine.
The longer its left the less likely you are to get a resolution.

[jwalker]

Jeez stop guessing!

From Bruce's figures:

Transom cut-out to bottom of V = 570mm.
Current leg length from anti-vent plate to saddle is 635mm.
Anti-vent plate is currently level with the bottom of the hull V.

So, 635 - 570 = 65mm. Therefore 65mm down is the lowest an engine can be mounted without transom modification.

An engine with a 'long' leg is 508mm from anti-vent plate to saddle.
Since the transom is 570 then 570 - 508 = 62mm. So 62mm, as near as damn it 2.5", is the lowest position the anti-vent plate can be if using a 'long' shaft motor.

[Last Tango]

Originally Posted by jwalker

Bruce, that's exactly as it should be and you're not going to get it better by changing shaft length.

These folks telling you to get a shorter shaft can't do their arithmetic.

Also, they don't seem to understand that keeping the props in the water as much as possible will give you best overall performance.

Watch this video and note that, with the exception of when the boat actually leaves the water completely because of its speed, the drive is low enough to to keep propelling the boat, even when the hull is out of the water. The requirement is that the section of the hull rear of the bow is the running surface and if possible the hull should run and land on that.

If you go the route of lifting the engine too far, which a shorter shaft will force you to do, when your hull leaves the water you will also loose forward drive and the hull will be dead stick until it lands and the prop has time to regrip the water. During this time you will be at the mercy of the hull angle and the type of wave it lands on - it is effectively out of your control during that time. This will give you a seriously uncomfortable ride in the Solent chop. On the same tack, a propeller which can run partially surfaced without loosing grip will also help considerably in keeping the drive on giving you best performance and best ride.

Since your boat is a rib, much of its safety relies on the bow being high giving you advanced handling in following seas and steep seas. Keeping your engine low, provided it's within an acceptable range, which your is, will give you the maximum leverage at the transom to lift the bow by applying throttle so enhancing your ability to keep making progress when others are struggling.

Stick with it and learn your new engine is my advice.

It's unfortunate that the clearance with your A-frame is a nuisance but that can be resolved. And if you resolve that, you still have the ability to lift the engine one more hole should you feel it's necessary.

Go and use it and enjoy your new power.

1) Set 1" above the hull it won't loose grip because that's where it should be.
and in fifty years of powerboating I've never found "loosing grip" to be an issue. Set it right and trim it right.

2) Race boats don't use standard underwater units. Their setup is completely irrelevant to a standard outboard rib.

3) You absolutely do not want to hold the bow high. Risk of catching wind under the hull, it will land hard on the aft section and risk of flipping the boat on a steep sided wave. (there's a good example of that happening to a lifeboat on youtube.)

4) Hitting the "A" frame is not an inconvenience. The engine is mounted too high. Why else would it hit the"A" frame?

[jwalker]

Originally Posted by Last Tango

1) Set 1" above the hull it won't loose grip because that's where it should be.
and in fifty years of powerboating I've never found "loosing grip" to be an issue. Set it right and trim it right.

Read the arithmetic. And loosing grip is a constant frustration in power boating hence all the talk about suitable propellers and engine heights!

2) Race boats don't use standard underwater units. Their setup is completely irrelevant to a standard outboard rib.

Nope. I use exactly the same drive as the V24 in the video. Completely relevant to a rib.

3) You absolutely do not want to hold the bow high. Risk of catching wind under the hull, it will land hard on the aft section and risk of flipping the boat on a steep sided wave.

There is always a ridiculously silly example to try and prove a point.
Look at the RIB at the head of your Ribnet screen, it's a good running RIB with the bow high and a surprisingly similar attitude to the V24s in the video and while it's obviously on smooth water, with a bit of luck it will keep that stance while travelling over waves.
Plainly there will come a point for any RIB where the waves are too big for it to keep running at speed and that is where the RIB excels and where a well rigged boat and good driving become the important factors.

4) Hitting the "A" frame is not an inconvenience. The engine is mounted too high. Why else would it hit the"A" frame?

The engine is a different physical shape to its predecessor.

[charliee]

I'm beginning to wonder if JW was responsible for this, of course the engine is a different physical shape, the new XL shaft is far longer than the old, long, shaft Opti. Had it been a standard shaft Suzuki then the difference would not be that great.

[Last Tango]

Wake up and smell the coffee.......

[beamishken]

Originally Posted by Xk59D

What a lot of nonsense.....

Wrong engine end of discussion

Originally Posted by jwalker

Whatever...

Not often I agree with Xk59D but on this occasion I 100% agree with him
1" up is where to start and the engine should be longshaft not extra long as supplied

[jwalker]

I give up. The arithmetic is in front of you.

'there's none so blind as those who will not see'

[Pikey Dave]

Not wishing to disturb your bitch slapping contest, when a XL, L, standard etc. shaft engine is mounted on its nominally correct transom, would we expect it to be mounted on the middle holes on the transom bracket? I.e, is a longshaft a longshaft when measured from the centre of the bracket or top/bottom?

[Jeff]

Bitch slap [emoji28][emoji28][emoji28] pmsl as they say [emoji4]

[Jeff]

Originally Posted by jeff

bitch slap [emoji28][emoji28][emoji28] pmsl as they say [emoji4]