avon sr5.4 engine height

[tim2658]

i have a little problem when im going 3/4 to full throttle, im getting alot of water being pumped over the transom right under the outboard,has anyone had this before, the only thing i can think is the motors to low but the cavitation plate is not far of inline with the bottom line of the hull ?????

[HUMBER P4VWL]

Yep, ours used to do that, sort of bubbles over the transom after 3/4 throttle. We had an optimax 90hp on a 5.4m. Only did it with the 90hp opti, not with an old 2 stroke 75. Never figured out why it did it sorry, but it didn't always happen. Only thing i could figure was either weight distribution or just bad design for that bracket of speed. They bloody shift, great boat.

We never bothered sorting it as the transom was so low on the SR and with no well at the back, water was always sloshing round.

There are many SR owners here, some with 115hp on the back so I'm sure they will give you a more detailed answer or importantly solution!!!

[tim2658]

cheers paul your right she does shift lol !, looks like i might cut out a well then ,cheers tim

[HUMBER P4VWL]

Not sure what to make of that. Ask others before doing it unless you know what you are doing. However it would be a handy addition, we never wanted to change from standard.

Have you sealed up the back to stop the inner hull flooding? this helps massively at slow manouvering with regards to water over the back. Also gets up on the plane quicker.

We bought a new SR 5.4 back in about 1999, can't quite remember but i think the transom plate said max hp 90. That was before the modern fueled injected 2 strokes. There is a high possiblity that the power is too much and the speed so high that hull design causes the water.

On your own with one tank, it used to be like a rocket on the flat. Never had a speedo but i'm sure just as fast as our humber 6.3 with a 150. (Though not in the waves) I do miss it on calm or choppy days.

JSP a member on here has a 5.4 with a 115, pm him and ask how he fares?

[tim2658]

no i was only joking paul about the well its just took me long enough to put the new deck in, i think i might take it up a bolt hole tomorrow and have a play, im really tempted to block the hull up did it make it that much better .

[HUMBER P4VWL]

i thought so. we ran it sinking for 2 years then i got fed up with low transom height and bow lift when getting up on plane. If you think of the weight that falls to the back then has to drain out, it is significant. We used to ski a lot and it was so annoying, as when people dont get up, you are from standing start to on the plane all the time.

You can get up on the plane so much quicker, then throttle back off much earlier. If you blast about from standstil to plane on and off all day (which we did) think of the fuel you will save!!

Obviously there is the arguement that if you just cruise, once the water is out its is out.

Just try it, there is a kit you can get to plug the front holes and another bit for the back. Can easily be removed. Though we found the back bit crap and only used it for one year. After that we glassed it up and put a screw bung in just to drain any bits out that seep in etc at the end of the season.

Good luck.

[tim2658]

cheers paul for that very helpful ,any idea where you can this kit from

[HUMBER P4VWL]

This was where we bought our boat from in 1998 ish. Think we got the kit from them. Give them a call.



Premier Avon Dealer & Rib Centre Boats & Yachts Website
Oakley Wharf Porthmadog Gwynedd LL49 9AY
Tel :01766513545

Established in 1980, Glaslyn Marine specialises in Chandlery with the emphasis on accessories and safety equipment. During 1990 it expanded into Inflatables and Liferafts, with the addition of a Service Station to its credits the following year.

[tim2658]

thanks very much paul i will give them ago, many thanks tim

[Nos4r2]

Originally Posted by HUMBER P4VWL

We bought a new SR 5.4 back in about 1999, can't quite remember but i think the transom plate said max hp 90. That was before the modern fueled injected 2 strokes. There is a high possiblity that the power is too much and the speed so high that hull design causes the water.

Nah, the modern injected strokers put out bang on their rated HP whereas the older ones are usually a little more than their rated HP.

[HUMBER P4VWL]

Fair point. Wasn't sure, just trying to figure it out. Perhaps it is engine height. Does yours do it?

[JSP]

Mine doesn't seem to do this (not that I've noticed) but will check on Sunday.

Regarding the kit to block off. I contacted Avon a few months ago to see how much it sells for. Got a reply back off them saying they hadn't had them on sale for a long time. Expensive to make as they were over engineered and lack of demand made it not worth doing.

[doggypaddle]

if you just want to try it blocked to see if you prefer it then you could do what i did, two plastic wine bottle corks and tube of silicone sealer for the front, and a piece of wood, a wood screw and a rubber backing disc off a black and decker sanding attachment and sealer for the back, will block all the holes up nicely.
TBH though you may as well get some nice expanding rubber bungs for the front and a piece of stainless with a drain plug for the rear and do it properly, because once you block it up i dont think you will ever want to unblock it.
i dont think you will get an SR5 dry though, theres always an inch of water in the bottom, though on saturday in NOS4r2's boat it was more like knee deep some of the time
I did notice some water coming in NOS' boat up the leg at some speeds, but only a very little so i guess all seariders may do it to a certain extent, i have seen it on mine too at around 20-25 knots when trimmed right in with 100 liters of fuel on the stern. not noticed it at higher speeds, trimmed out, or with less fuel. Raising the engine one hole helped a bit. its one hole off the lowest now.