Yamaha 8hp 2 stroke outboard

lanerboy said:
Only plated for 6hp Jimmy but I know people exceed the recommended hp I remember seeing a picture JFM put up with a huge outboard on a tender which was obviously way over the limit not that I will be doing that lol
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It wasn't one of these was it? :)

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I have a 2 stroke Johnson 6hp Twin, and it pulls my Avon 280 Rib onto the plane easily, and as it revs to oblivion will haul it up to 20mph according to GPS!

It can be upgraded to 8hp just by changing the reed block apparently, but it's a bit excessive for the upper thames where it's predominantly used.

So I'll sell it and buy a smaller one if you're interested!? It's the latter version, not the older 'angled' cowl model. It has a remote tank and nice fron mounted gearlever. Works perfectly, recently serviced no issues at all...
 
lanerboy said:
Is this hard to do and what parts would be required new gaskets etc etc
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No. Not hard to do. One bolt from memory is a bit awkward to get at, but as long as you lift the "plate" that exposes the waterways carefully, no gaskets etc required. Mine's still all original, and I bought it in 2002.
 
If you are finding that the bow lifts and you can't make it out the hole without leaning over the bow, an alternative to dolphin fins are smart tabs. Relatively cheap and (at least on my cuddy) do have a pronounced beneficial effect. http://www.nauticusinc.com/smart_tabs_automatic_trim_tabs.htm I long considered putting them on my tender but because I often fold the tender away and have dolly wheels on the transom went the dolphin fin route too.
 
lanerboy said:
Only plated for 6hp Jimmy but I know people exceed the recommended hp I remember seeing a picture JFM put up with a huge outboard on a tender which was obviously way over the limit not that I will be doing that lol
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Yep, I remember that picture too - 25hp, 2.1m. Forumite tcm. Nuff said.

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My Yam 8 will get my Zodiac 3.1 inflatable on the plane easily with 2 adults. It will do 20mph (GPS) with just me plus 20l fuel.

As a twin it has more torque that the 5hp single.

The Enduro has a leg from the smaller models. The exhaust is not through the prop. Probably this gives a weight saving.

On Malta, all the tour boats to the Grotto run Yam 8 Enduro's. They each shift 10-12 people in a heavy displacement boat, which was quite impressive.
 
I have a Yamaha 15 2st in the Garage that runs well, and has recently had the gearchange stripped and lubed and refitted (common fault, jamming) - I might let that go if you can go that big - but as mentioned, I'd want decent money for it as these engines are getting like hens teeth now.
 
That's about right 1 up. Good fun. Not two though, on mine leastways (2.8m). Just not quite enough power to get out of the hole. Ever so close but just ......nnnnnnng... nope. But if the admiral is in the bow it keeps her bum dry as the nose lifts so it's still good. Hopefully your's will be just that bit more efficient :encouragement:
 
BruceK said:
That's about right 1 up. Good fun. Not two though, on mine leastways (2.8m). Just not quite enough power to get out of the hole. Ever so close but just ......nnnnnnng... nope. But if the admiral is in the bow it keeps her bum dry as the nose lifts so it's still good. Hopefully your's will be just that bit more efficient :encouragement:
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Fit a set of Dolphin fins, they do work.
 
ontheplane said:
I have a Yamaha 15 2st in the Garage that runs well, and has recently had the gearchange stripped and lubed and refitted (common fault, jamming) - I might let that go if you can go that big - but as mentioned, I'd want decent money for it as these engines are getting like hens teeth now.
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Sure are , I've got one too, might sell for right price.
 
Old thread but I’ll add my 2 bits.

I have a 12’ Porte Bote, 70 pound folding boat. I had a 8hp Yamaha (non-Enduro 100:1 mid, exhaust through prop) and it ran like the wind. It would plane me and the missus and with me I could not open it up.

I moved that motor to a different application and bought a brand new 2017 Yamaha 8hp Enduro. 50:1 mix engine) It’s a complete do, misses at low RPM, can just barely get it to plane me alone. I’ve tried changing the prop with no positive effect. We are cruising so there is no going back to the seller. I’m waiting to find a Yamaha dealer that can take a look at the engine.

While I’ve never heard but good things about these engines I could not recommend one based on my experience. Hopefully I’ll find a decent mechanic and sort this out. Otherwise I’m gonna ditch it.
 
I've had my 8hp yahama 2 stroke now for 12 years. Been serviced twice. Been on 3 tenders, first two couldn't cope with being driven up the beach and fell apart. Ribeye 3.2 I think I have now, can plane still with two people (long as you're not fat) . Yes more power is faster but you can't carry it up the beach so unless you want to water ski you want power/weight ratio that planes.

Written in the style of Haydn just because.
 
Best small 2 stroke there is pound for pound. Same weight as a new 4 stroke yamaha 4hp and twice the power and torque.
The 9.9 and 15 are heavy beasts. No good for lifting on and off too often.
With a boat like yours it will be fine with 2 or even 3 adults and will plane.
Strangely enough, on shorter ribs, they struggle with 2 or more. Too short a hull to plane easily.
I’ve had mine on a valiant 3m and it flew, planing with 3 adults. Put it on a much shorter and lighter Brigg and it struggled.
 
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