Avon searider sr4 60hp?

[Livid]

Hi all.
In 2013, my great uncle was getting off the water, so he sold me his 1985 4m searider, with trailer and a ‘97yamaha 40veto engine for much less than what it was worth. The boat was mostly stock and fairly well maintained, apart from a wooden storage box to house the tank in the back. I’ve since moved the tank to it’s proper mount in the front to try and rectify balance issues and thrown in an electric bilge pump, but it’s not perfect. The battery is still housed in this box, and removing the fuel tank has opened up a lot of room for jerrycans and the cover and so on. My uncle has an identical searider, but he spent quite a lot of money refitting his (I suspect new/refurbished tubes), and before I bought mine, he switched the engines on them, as mine used to have an 80’s yamaha 60hp autolube, which he now uses. That 60hp engine has a whale tail fitted, my engine doesn’t use them
I am planning on doing up the boat at the end of next season, as it looks a bit tired, and I am considering replacing the engine as the 40veto has a few issues. It’s quite a thirsty engine, getting through it’s 25L can in 2-3 days of my driving. But the main issue is that the previous owner took a small chunk out of the lower housing of the engine at the seal for the cover, and as a result every time I come off the plane (the fill and drain holes haven’t been sealed) seawater gets into the back of the engine and starts corroding things, and by the end of the season the bottom cylender stops firing, making it a 2cyl engine with an irritating loss in power, and then a hefty repair bill usually in the region of £300-400 at the end of every season. Where I live the late 90’s yamaha 2 strokes are still very desirable because of their reliability. Mine has never outright stopped on me, It’s always gotten me home, but it is time for change. The transom has only it’s stock reinforcement in thte two stainless gussets on either side, my uncles boat forgoes the gussets in favor of some serious fiberglass reinforcement. I’ve been looking at the evinrude e-tec 60, as it falls just under the transom weight of 110kg (it weighs 109). My worry is whether the transom needs more work, as I suspect when it had the yamaha 60 on it it was driven fairly gently, and I dont do gentle, it has been and will be thrashed, it’s just so much fun to blast about. I don’t want to lose the wooden storage box i’ve got, so I was wondering if I could get away without extra reinforcement, and if it was needed, just double up on the stainless or some other similarly non drastic reinforment, such as some fibreglass at the ends of the trasom so it doesn’t interfere with the bos, as there’s only aobut 3in of room from the front of the transom to the back of the box, and the box stops about ½ ft from the tubes at either side. I know the e-tec won’t offer a significant fuel consumption advantage, but not having to pay that damn £400 bill every season will help a lot. I also need the extra power, as it cannot keep pace with my father’s boat, which causes issues as they usually end up waiting at anchor for 20 mins while I catch up. The extra hp should allow me to match or exceed their speed.
I appreciate the help
Harry

[beamishken]

My son's sr4 came with a 70 mercury clamshell so people do fit bigger than the recommended 50hp.
I've got a 40veto on another boat and think it's a peach of an engine
If I was comparing 2 stroke yam with 2 stroke yam for your boat I'd go for the 50 as it's slightly lighter and has the smaler diameter gearbox than the 60 so I doubt there'd be a massive gain
Obviously an etec is totally different to an old school 2 stroke but for the extra cost you can buy a whole lotta fuel
What about sorting the pan issue and upgrading the engine to 50hp spec?

[Livid]

Mine has run a 60 before in it's life, that engine is currently on my uncles sr4 as he grabbed it before i bought it. New Yamaha 2 strokes are basically impossible to get in the UK because of EU emissions laws, you can get them for commercial use but not for private use.
The problem is the hole is on the bottom casing of the engine, so it needs to be entirely rebuilt into the new casing. I don't have the time or skills to do that myself, and i'd probably screw it up. Getting a professional to do it would probably cost about half what a new engine would. I might try a bit of body filler though. If i wanted to upgrade it to 50hp what would i need to do? just the carb?
It also stalls while idling, which drives me up the wall when im trying to dock.
I do like the engine, I've never had it outright quit on me. It's always gotten me home, just once i'm home i need to pull the lower ht lead off and bang out all the corrosion.

[Nos4r2]

You are aware this is a UK site?

[Livid]

Originally Posted by Nos4r2

You are aware this is a UK site?

TBH i didn't know that, but i do now. thanks

[Nos4r2]

Originally Posted by Livid

TBH i didn't know that, but i do now. thanks

No worries, just take it as red we know all about difficulties getting motors/premiums on Yam 2 strokes etc.It'll save you a lot of typing.
Welcome to Ribnet btw

If your gear casing is holed, you need another one really as your chances of getting it apart are pretty slim.
Has it had salt water through the hole?

[Livid]

Right at the back of the engine, very near the latch for the cover, the hole is on the edge of the casing, so the canopy doesn't seal right, i know there's been seawater through the hole as it's been corroding the bottom spark plug and HT lead.

[Nos4r2]

Oh hang on, you mean the lower cowl has a lump out of it? Thats a couple of hours work if it's not all seized on the mounting bolts.

[Livid]

I suspect it has very definitely seized up all the bolts as the hole's been there for at least 5 years. I'm going to try body filler first.

[Nos4r2]

Even if it has seized up, as long as you've got another lower cowl and bolts it'll be easy enough. It's only bolted to itself and (via brackets) the powerhead. Just try not to undo any mounting bolts on the powerhead itself and you should be ok to just shear the bolts.

Body filler isn't a good idea by the way. It absorbs moisture, so the edges of the hole will corrode and it'll fall out. Clean the edges of the hole right back til shiny, degrease, rough up then use epoxy filler with something behind it to stop the filler falling through (Gaff tape will do)

[Livid]

The other minor irritation is that I store the boat in Cornwall, a good 200 miles away from where i live. I kept up the deal my great-uncle has with a mechanic in St Mawes, where he winterises it and keeps it in his yard over winter, to save me towing it back which would not be fun. However that also means it's basically impossible for me to do any work on it, so i have to pay through the nose to get him to do it. He's kept his mouth shut about the lower cowl as he quite likes charging me £400 for the coil/ht lead unit and a spark plug every year. I can do the filler myself, ill probably just beach it next summer to get it done. What parts do i need to upgrade it to 50hp? and would a different prop help? I can't remember what it's got fitted right now unfortunately, i'll email the mechanic today and find out. Like i said before i thrash it, i marginally prioritise top speed over out of the hole, because i know the hull filling feature of the searider dulls out of the hole significantly, but it's quite fast on the plane as is, and i dont want to make it totally lethargic

[Nos4r2]

It shouldn't be at all lethargic with a Yam 40 on. What prop is on it, and is the engine power trim?

[Livid]

Thanks for the advice. I know of a chandlery i could get some epoxy from, as I need some for another project next year anyway. I'm studying for an electrical and electronic engineering degree, so I don't really trust myself working with the big oily bits, and I really don't want to pay through the nose to get a professional to replace the lower cowl. It's the limit of my engine knowledge to check fuel and ignition etc, basic servicing stuff. I dont think i'd be able to do anything any more ambitious on the mechanical side.

[Livid]

Engine is PTT, i don't know what prop it's got on it from memory, but i can easily find out. to go to 50hp does it just need reed valves and rejetting or does it need a whole new carb? Also is it normal for these engines to stall after 2min of idle in neutral? it's a PITA when i'm moored as i think i've killed the engine, then leave the ignition on and need to jump start it the next day. It also sucks when i'm picking up people from a dock

[Livid]

It's usually ends up being lethargic because of the corrosion issue, so it ends up running on only 2cyl, and it really struggles to get on the plane on 2cyl

[Nos4r2]

First, if you're running it on 2 cylinders it's not good for it. Shouldn't be using it, you'll cause yourself more issues.It should be quite fast (35 knots+) with a properly set up 40hp Yam when solo.

Second, it'll be easier and safer to buy a 50hp and fit it than to convert it to 50hp if you're uncomfortable with basic mechanical stuff. You'll open yourself up to all sorts of bills if you ask a marine tech to do it. If it doesn't run exactly right immediately , you'll be paying by the hour for fixing the snags.

[Livid]

I know i shouldn't be running it on 2, but I've got to get it home somehow. It definitely cannot hit 35kt solo as my dad's boat has a chartplotter and we know that maxes out at about 35, and even on all 3 it cant keep up, even with my younger brother in the drivers seat (he weighs about half what i do). I wasn't planning on doing the conversion myself, one of my cousins is very mechanically inclined (he did a similar upgrade on a honda 15hp taking it to 20 and keeps a full toolkit not just a socket set on his speedboat), and he's said he'd do it for me/help me with it if i could source the parts

[Livid]

Don't worry, i wont come after you if I blow up my engine

[beamishken]

If you message Davie here on the forum he will know exactly what is needed to upgrade to 50hp he's a yamaha dealer and could supply you the parts if you go down that road.

Even using a dealer to sort your engine properly with a used pan and upgrade I doubt you'll spend the equivalent of 1 years depreciation on a new etec
The 50yam is considered the best engine to match to an sr4

[spartacus]

All this talk of 50hp 2-strokes makes me smile. The Yamaha 2-stroke 3 cylinder engine otherwise known as model 40V is a masterpiece of engineering. Bullet-proof if properly maintained.

The 50hp version, model 50G shares the same powerhead, gearbox, etc, but from my understanding has different carbs, increased exhaust manifold, etc. Only trouble is they were favoured by the commercial sector and are as rare as rocking horse poo.

You could land lucky and find one. If one does come up for sale then be prepared to travel, see it running, run a compression test on it across all 3 cylinders and service it within an inch of its life.