Outboards

I need a new outboard as I have lost the use of my 5hp 2 stroke mercury 
I have a 2hp johnson seahorse that is capable and very good for getting of and on mooring. However I have to travel a long way up a tidal river to get out to sea and find the 2hp 2 stroke is to slow and working to hard.
I really want another engine as I always like to carry a spare anyway and am looking at the new 4 strokes which are heavier and I am told less powerful.
I was hoping that a new 3.5hp might be big enough but I wonder if it will be less powerful than the johnson?
Has anyone got any experience of new 4 stroke engines compared to old 2 strokes i.e how much higher do you need to go to emulate the same real world power.
So for a old 2 stroke 3.5hp would a 4hp 4 stroke be as powerful or more powerful or is the difference between 4 and 2 stroke negligible for sail boats?
many thanks desperate to get out now lock down is easing if anyone has an old outboard sitting gathering dust please sell it to me

I use a 4hp yamaha on my Seahawk. It's more than adequate to get me up the Camel Estuary on a spring ebb.  I also have a spare 4hp Johnson twin 2stroke that I could be persuaded to sell.  It runs very well and has seen little use. It is the model with just forward fixed gear so for reverse you swing the motor around 180 degrees.  It's in Devon - where are you?    Regards  Brian

I am in the wilds of Norfolk Brian so bit to far for me to travel sadly or I would be using all my persuasion skills.
Is the 4hp Yamaha a newer 4 stroke model Brian?
I have used a 5hp 2-stroke which was more than adequate but I was just wondering about the newer 4-strokes in comparison to the 2-strokes I would like to buy the smallest 4-stroke that will reach hull speed comfortably so it is probably going to be at least 4 or 5 hp

Cheers

 Norfolk is a bit far but I have couriered outboards before - I think it would cost around £20.  Most couriers don't like carrying them though as they always smell of petrol even when drained.
My Yamaha is a 2 stroke from the late 80s - ultra reliable and very light compared to the early 4 strokes.  I much prefer 2 strokes as you get a better power to weight ratio.  Johnsons are even lighter and being a twin run a bit smoother .  There are plenty round your way - have a look at FB Marketplace and Gumtree.  

Thanks Brian I will keep my eyes peeled.
I have just had a 6hp evinrude given to me with a view to testing it out if I can get it running but I think it is far to heavy.
As we are going to have to move to 4-strokes eventually I wondered if it was an option - although after Brexit maybe we will be able to go back to proper 2-stroke engines!

Just an update about outboards:
My little Johnson 2hp did push the seahawk along and would certainly be adequate as an emergency engine or for getting on and off a non tidal mooring or at slack water when no current is running. In fact I found that it was easier to steer the Seahawk backwards with the outboard turned 180 degrees than to try and go forwards onto the mooring or through the tidal lock I have to negotiate. Much better than my previous engine that had a selectable reverse. However it was not really practical for my own long river journey out to sea with the mast down. Hoping that now the season is coming to the end I can sniff out a decent outboard for next year or maybe even catch a few waves before the doom and gloom of winter set in

I would look for a 4hp Yamaha or Mariner 2 stroke.  Mine is light and very powerful - it pushes our seahawk along at around 5.5 knots.  That is more than enough to push against a spring tide on the R Camel at Padstow.  I like these engines because they are very reliable and easy to service.  They are light enough to carry and swing up nicely when we are sailing.  I also like the 3.5hp Mariners for the same reasons - I used one to bring a 21 foot Westerly into the Dart against the ebbing tide!