Inflatable boat owners, what sort of oars attach here?

[rcx132]

So it sounds like 50:1 is safer but 100:1 reduces fouled plugs.

I would say it was worth contemplating changing the impeller, as they get old, even if not used. ... if corrosion has set in, it could turn into an epic. If

I don't think corrosion has set up, as I've been able to take a few bits apart. I guess that's rare on a 25 year old marine engine? I'll have to look after it and hang onto it then.

 

[Tinbasherdan]

So it sounds like 50:1 is safer but 100:1 reduces fouled plugs.

I don't think corrosion has set up, as I've been able to take a few bits apart. I guess that's rare on a 25 year old marine engine? I'll have to look after it and hang onto it then.

Oils have come a long way in 25 years, 100:1 will be fine. Keep her on the plane and she will be happiest singing away.

Another aside (admittedly I have no idea on your boating experience) don’t tickle it putting it into gear, be positive and mean it. Best for the box

 

[lotus_esprit_s1]

So it sounds like 50:1 is safer but 100:1 reduces fouled plugs.

I don't think corrosion has set up, as I've been able to take a few bits apart. I guess that's rare on a 25 year old marine engine? I'll have to look after it and hang onto it then.

Yamaha designed your 20hp 2cyl single carb in 1972 from memory and was unchanged until they ended production in the mid 2000’s. It has always been 100:1 and this was a major selling point back when they came out. The later European market 20D/25N twin carb with autolube (not as nice as the earlier engines) ran a variable oil ratio and would run at 200:1 on tickover.

How old is this 20hp? cowling graphics changed every 3-4 years. They went from blue to grey in 1994. There should be a hidden letter stamped in the serial number plate which gives the year of build, or later ones are just printed stickers with a letter marked on it.

 

[rcx132]

How old is this 20hp? cowling graphics changed every 3-4 years. They went from blue to grey in 1994. There should be a hidden letter stamped in the serial number plate which gives the year of build, or later ones are just printed stickers with a letter marked on it.

It's a 1998. And my apologies, its 25hp, Yamaha 25VMH.

I'm surprised two strokes were made so late, they put oil into the water via exhaust right? Can't be too good for water life.

 

[Keith 66]

Had some outboard fun yesterday, Sons outrigger canoe's maiden voyage, put the 5hp Johnson on it (early 90's), I got this engine years ago & it has never done anything literally sitting for years unused, Always utterly reliable it started playing up a couple of years ago, new fuel hoses & cleaned the carb sorted it.
Yesterday it started & ran fine for about 5 minutes on fresh fuel, it drove the canoe at about 9 knots so good performance, then it just petered out & died.
Had to paddle back to the slipway & get the spare outboard a little mariner 2.5, fortunately that worked!
Cooling fine, Thinking tank breather blocked checked that & its clear, Head scratching time now. I mean this engine is barely run in & now its letting us down.
Think it will be spanners out later & put it on the outboard tank.
As for bolts, always grease them they are that special lead based alloy designed to snap off as soon as they seize which means all the time!

 

[lotus_esprit_s1]

It's a 1998. And my apologies, its 25hp, Yamaha 25VMH.

I'm surprised two strokes were made so late, they put oil into the water via exhaust right? Can't be too good for water life.

The 25V is actually a down tuned 30A. By 1998 Yamaha had pretty much perfected their build quality, the bolts etc are much better than earlier models

I’m out of the outboard game now but Yamaha were still making two strokes two years ago to order if you were a commercial operator In the UK. They probably still make the 40hp for Africa / egypt etc, it‘s the only outboard they‘ll use

 

[dobbslc]

Oils have come a long way in 25 years, 100:1 will be fine. Keep her on the plane and she will be happiest singing away.

Another aside (admittedly I have no idea on your boating experience) don’t tickle it putting it into gear, be positive and mean it. Best for the box

Well I've learnt something new today!
Yamaha two stroke engines can run at 100:1 fuel ratio and boats have gearboxes!

 

[addjunkie]

Well I've learnt something new today!
Yamaha two stroke engines can run at 100:1 fuel ratio and boats have gearboxes!

Only those below 75hp! Not all boats have gear boxes. Big marine two strokes run back wards to drive the boat backwards

 

[dobbslc]

To be honest I'd be sxxx scared running a two stroke at 100:1 ! I'm used to 20:1 on Castrol R

 

[Tinbasherdan]

Well I've learnt something new today!
Yamaha two stroke engines can run at 100:1 fuel ratio and boats have gearboxes!

Forward and reverse. Ok a simplistic box but it has one

 

[cheb]

Some of the really small ones don't have gearboxes. If the engine is running the prop is rotating. Want to go the other way? Turn the engine through 180 degrees.

 

[Tinbasherdan]

Only those below 75hp! Not all boats have gear boxes. Big marine two strokes run back wards to drive the boat backwards

Dads stepdad was an engineer on a diesel tug (oddly it’s in preservation in Liverpool, mt brocklebank) and that relied on the engine being reversed. On harbour jobs apparently it was common to be telegraphed astern, and by the time you’d stopped and restarted the telegraph was showing forward again

 

[addjunkie]

Dads stepdad was an engineer on a diesel tug (oddly it’s in preservation in Liverpool, mt brocklebank) and that relied on the engine being reversed. On harbour jobs apparently it was common to be telegraphed astern, and by the time you’d stopped and restarted the telegraph was showing forward again

Doesnt surprise me, big engines have lots of inertia and take time to stop.

 

[redlig]

Inflatable oars ?

Seen a few of those about.

 

[Misterg]

Doesnt surprise me, big engines have lots of inertia and take time to stop.

At something of a tangent to blow up boats, [understatement!], I overheard a comment at the Museum of Internal Fire today that led me to the 'River Don Engine'; A 420 ton, 12,000 horsepower (nearly 9 MEGAWATS!) steam engine that can be flung into reverse from full speed and be running in the opposite direction in about 2 seconds!

Built?

1905

Last used in the 1970s to roll out reactor shield plates for nuclear power plant.

River Don Engine - Sheffield Museums Trust

www.sheffieldmuseums.org.uk

I've got to get me to Sheffield (once they've fixed the boiler).

 

[addjunkie]

The triple expansion steam engine is quite a majestic beast. As an apprentice, I was lucky enough to spend a day on an old collier called the Sir William Walker, the last of the steam recip colliers operated by Stephenson Clarke shipping for the CEGB.

The 85 hp Yamaha two stroke was far more fun than the 25000 hp Sulzer diesels.

 

[Cobbler]

At something of a tangent to blow up boats, [understatement!], I overheard a comment at the Museum of Internal Fire today that led me to the 'River Don Engine'; A 420 ton, 12,000 horsepower (nearly 9 MEGAWATS!) steam engine that can be flung into reverse from full speed and be running in the opposite direction in about 2 seconds!

Built?

1905

Last used in the 1970s to roll out reactor shield plates for nuclear power plant.

River Don Engine - Sheffield Museums Trust

www.sheffieldmuseums.org.uk

I've got to get me to Sheffield (once they've fixed the boiler).

It’s well worth a day at the Kelham Island museum, very well laid out & interesting