Avon 4m Speed

Brian_Pal · 20 May 2004, 16:39

I have a Avon Searider 4m with a Honda 45 hp 4 stroke on it right now. The engine is in the shop for repairs, and depending on how severe it is, we might just sell the engine. A friend has a 2 stroke Yamaha 50 that he bought new last year, and used for a few months. Now it's just sitting in his garage, and was thinking of possibly picking it up for my 4m.

What would be a good price to offer for a good used yamaha 50? Would it make my RIB faster, and if so, by how much? I know some of you have 2 stroke 50's on your seariders, how fast do they top out at? How much more fuel would it use? Would it be a lot louder than the Honda?

Thanks!

Brian Pal

Tim M · 20 May 2004, 19:42

More fuel (1litre per house plus) much noisier, and a little bit fasting (7/8knots maybe?)

Pitkis · 20 May 2004, 20:19

I have driven hundreds of miles SR 4 with 45 hp Honda and Mercury 50 hp old two stoke engine. Mercury is definitely faster and gives much better acceleration. In heavy swell Honda is hard to get boat to plane with two persons on board. Otherwise Honda is better in general IMO. Honda makes some 32 knot (1 person, trimmed) and Mercury some 33-34 kn. So not a big difference especially when you remember that speeds over 30 knots SR 4 begins to be a bit unstable.

ollyit · 20 May 2004, 21:49

sorry to hear about your honda - hopefully fingers crossed it wont break the bank - if yours turns out to be okay would your friend be likely to want to sell it to another searider owner by any chance do you think?

Phil Davies · 20 May 2004, 22:06

Quote:

Originally Posted by Pitkis

So not a big difference especially when you remember that speeds over 30 knots SR 4 begins to be a bit unstable.

Just what I didn't want to hear, Pitkis! Having decided to keep my SR4 for a while longer, I am about to upgrade my Honda 30 to either an Evinrude 50 ETec 2-stroke direct injection or Suzuki 50 EFi 4-stroke. I have managed a maximum of 26knts in a flat sea with my Honda but am a little disappointed to hear that at only 4knts more the boat becomes unstable. Does this mean I'm wasting my money upgrading to a 50 since my aim is to achieve higher top end as well as better acceleration? I'd be interested in your views before I splash the cash.

Brian_Pal · 20 May 2004, 23:29

Thanks for the replies.

We'll see what happens, going to take a look at the Yamaha 50 today... Hafta see how much the mechanic wants for the honda 45 repairs. It dropped a valve and blew a hole in the no. 2 piston and messing up the head.

Ollyit- I'm sure he would be willing to sell it to you, but it would prolly be a logistical nightmare to get a boat motor shipped halfway accross the world!

Phil Davies- Do you know how much transom weight is safe on these boats? I was looking at the Suzuki 50 EFI too, but it weighs 242 lbs. Has anyone talked to Avon about this?

The acceleration on my Honda dosen't seem too bad, but it does have a hard time getting on plane with a lot of people on board. (I got it on plane with 5 big guys once)

Would the Yammie be better at accleration/getting up on plane? I always thought that with a 2 stroke you would have better top end speed, but sacrifice acceleration/low end. Opinions?

Thanks!

PS. What do you guys think on a price? How much do these go for new? I can't seem to find a proce anywhere...

swginn · 20 May 2004, 23:52

2-strokes generally perform better right through the rev range, than equivalent four strokes. 2 stroke will have way better acceleration too, they are reknowned for this.

2-stroke for performance, 4-stroke for economy, noise (lack of!!)

Opti for both!!!

Bilge Rat · 21 May 2004, 07:48

Quote:

Originally Posted by Phil Davies

Just what I didn't want to hear, Pitkis! Having decided to keep my SR4 for a while longer, I am about to upgrade my Honda 30 to either an Evinrude 50 ETec 2-stroke direct injection or Suzuki 50 EFi 4-stroke. I have managed a maximum of 26knts in a flat sea with my Honda but am a little disappointed to hear that at only 4knts more the boat becomes unstable. Does this mean I'm wasting my money upgrading to a 50 since my aim is to achieve higher top end as well as better acceleration? I'd be interested in your views before I splash the cash.

How many times are we going to have to go over this Davies ?? bigger engine = more weight + more fuel/additional speed gained = lots more money and not a lot of gain, so ok we can reduce weight by going 2 stroke but the fuel costs increase and more importantly the amount of fuel you have to carry will increase upwards....have you thought of that one to ! remember a litre of petrol weighs in at 1 kilo, so an additional 24 litre container is an added 24 kilos your'll have to carry and of course your'll have to store this added fuel some place on the boat too ?
Why not as a cheaper alternative invest in a higher pitched prop, if you go up two inches and keep the same diametre your'll lose a little take off speed but gain a few knots top end ! so think about it....if you put a 50hp on and its going to cost you say 4-5k to do it and remember you have to have is set correctly on the transom too, and all you gain top end is 5 or 6 knots or you could spend £170 on a stainless prop with a 2 inch gain in pitch and gain say 3-4 knots !!
Also worth remembering your still only in a 4m boat, yep great on flat calm days on the Thames, but its not always flat is it, lots more speed will only make you take off between crests much quicker.
Not trying to put you off Phil in any way, i know your gagging to spend some money but just think about the overall costs longterm, i'm running a thirsty 50hp 2 stroke, when we go out i have to carry more than twice the amount of fuel as you do to get the same distance as you ! and your still managing to keep up with me! thats fact.

In MHO change the engine because its knackered or unreliable or keeps going wrong, but dont chuck it becuase you want a few extra knots, instead sell the complete rig as a good well balanced set up and by an 8 metre Scorpian.

Bilge Rat · 21 May 2004, 07:56

Brian

If i were you i'd walk away from the Honda and see what your mate wants for his Yam 50 once you start getting into rebuilds your'll open up a whole can of worms, i know i've been there and done it and it hurts i promise you

h

Suzuki416 · 21 May 2004, 08:07

Phil,

I hate to do this but I think that Bilge Rat is correct..

As a 4m owner with a 70 on the back unless it is very flat I cannot use the upper rpms of my motor..
Mine will quite happily go at 33 kts (haven't wound it all the way up yet as don't know rpms) BUT I find that I normally sit at 20-25 kts which is a lot more comfortable for 1. the boat, & 2. the crew, in anything over a F2.

If you want big waves & very fast - you need them big. (balls)

Sell the boat, use money to get a bigger RIB.

Pete

Alan · 21 May 2004, 08:08

Quote:

Originally Posted by Bilge Rat

sell the complete rig as a good well balanced set up and by an 8 metre Scorpian.

Which would look much better hitched up behind that Rangie of yours!!

Serious point. Don't bother changing your engine for a few more knots. Fact is you have a small RIB which is performing within its capabilitites.If you want to go significantly faster or out in different conditions then you need a bigger RIB IMHO. For example 4.8m Ribcraft will do 30ish knots. My 6.5m DS21 would do 38kts and cruised comfortably at 30ish. My Scorp would do 45kts and cruised comfortably at 40.

'sides if you buy a big Scorp then you'll never be short of crew!

Phil Davies · 21 May 2004, 08:29

Well that told me

By the way, will people laugh if I buy a chartplotter and fishfinder for my SR4, or should I wait until I order my Scorpion?

Alan · 21 May 2004, 08:33

Fishfinder & Chartplotter much cheaper than new engine so much better investment.

And of course can be transferred to your new Scorp!

Suzuki416 · 21 May 2004, 08:35

Quote:

Originally Posted by Phil Davies

Well that told me

By the way, will people laugh if I buy a chartplotter and fishfinder for my SR4, or should I wait until I order my Scorpion?

YES!!!

get yourself a fishfinder though!

Suzuki416 · 21 May 2004, 08:37

Quote:

Originally Posted by Suzuki416

YES!!!

get yourself a fishfinder though!

BUT NOT A GARMIN !

Phil Davies · 21 May 2004, 08:39

Cheers guys. I was thinking of the Navman 4100 fishfinder and Navman 5500i colour chartplotter. I understand the Navman plotters are very good but don't know much about their fishfinders - anyone know if they're any good?

Bilge Rat · 21 May 2004, 08:58

Phil

If it were my money and knowing the consoul space available to you i'd go for a combined unit, its likely to get very wet so i'd suggest your remit be completely water proof, Garmins are not completely immersion proof !!

A fish finder/echo is a great investment especially where i operate as its always shallow, dont underestimate your local knowledge though as its always valuable, the GPS map makes me lazy and i've started to rely on it even though i can read a chart and plot a course using a compass and timmings/speed over ground..... but what a great bit of kit.....my C Maps even worked right up the Thames last weekend :-)

May have come across an A frame that would fit your boat too, it was made for a valiant but didn't fit, i'd need to get the measurments and height but it looks the dogs nuts mate 40mm stainless steel and very shinny, not sure what sort of money but it wont be a lot as at the moment its scrap !!

Hey all this sensible talking today has to have earned me a few credability points

Bilge Rat · 21 May 2004, 09:00

Quote:

Originally Posted by Suzuki416

Phil,

I hate to do this but I think that Bilge Rat is correct..

As a 4m owner with a 70 on the back unless it is very flat I cannot use the upper rpms of my motor..
Mine will quite happily go at 33 kts (haven't wound it all the way up yet as don't know rpms) BUT I find that I normally sit at 20-25 kts which is a lot more comfortable for 1. the boat, & 2. the crew, in anything over a F2.

If you want big waves & very fast - you need them big. (balls)

Sell the boat, use money to get a bigger RIB.

Pete

Hey Suzuki......maybe your not as mad dog crazy as i had first thought

Phil Davies · 21 May 2004, 09:06

Quote:

Originally Posted by Bilge Rat

Hey all this sensible talking today has to have earned me a few credability points

I'd agree Rich, but when I pressed the button just now it told me I've got to 'spread some reputation around before giving it to Bilge Rat again'

The system clearly does not allow favouritism!
What I can say is, I certainly don't go spreading it around and I definitely won't be giving it to you

Suzuki416 · 21 May 2004, 09:18

Quote:

Originally Posted by Bilge Rat

Hey Suzuki......maybe your not as mad dog crazy as i had first thought

Oh, I don't know about that -

Just ask Kathleen (faster, Kate, faster)

Anyway, this advice is for Phil in his retiring years

not for me!

Pete
If you want big waves & very fast - you need them big. (balls)