How many horses do you need?
- Thread starter Gavi
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Gavi
Well-Known Member
How many phases do they needHave you seen Steins drop goal of 58 yards in SA
Against Clermont? Classic stuff
tinkicker0
Well-Known Member
Oiled plugs are plugs coated in oil as a result of them, the combustion gasses and the surrounding cylinder not getting hot enough to allow the oil in the combustion chamber to burn, instead it vaporises and condenses again. This is because 2 strokes are tuned for a particular rev band where they are efficient, get out of this band and either too much unburnt mixture exits the exhaust port, with poor cylinder filling leading to low combustion temps or too much spent combustion gas remaining in the cylinder lowering combustion temps.
It means slow speed misfires, cylinders cutting out completely and eventual silence. It also means the exhaust system eventually clogging up with oil sludge along with stuck piston rings.
As someone said, knocking out of gear and revving the motor will clear it for a bit, but it will become more and more regular as the crankcase fills up with unburnt oil that has separated out. Fecks plugs like nobody's business too.
Gavi
Well-Known Member
I had to read that excellent explanation three times and I still don't understand
tinkicker0
Well-Known Member
I had to read that excellent explanation three times and I still don't understand
New mixture either fecks off out of exhaust port instead of staying around to be burnt or old burnt exhaust gas stays in the cylinder instead of going out the exhaust if the motor is not in its tuned power band.
Either way the cylinder is not getting the correct amount of oxygen and fuel required for efficient burning and a satisfying bang.
Look up 2 stroke scavenging.
In addition, at low revs the crankcase fills with oil because some of the the incoming mixture has time to fall to the bottom of the case and not be picked back up by a fast moving gas stream, then the petrol evaporates leaving the oil.
This is why when following a two stroke bike pootling around town then opening the throttle, clouds of smoke ensue and then gradually clear from the exhausts.
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bendyone
Well-Known Member
I use a 6HP 4 Stoke on a 15 foot cabin boat, works well for me.
MapisM
Well-Known Member
Do tell, on which cars? Not an SZ, by chance?
Gavi
Well-Known Member
Nothing so exotic
I got the 4th RHD Spider 3.0 V6 into the country and then a 166 with the same engine. Both lovely cars with spirited engines. But they drank more than me!
boatone
Well-Known Member
MapisM
Well-Known Member
LOL, I know nothing about Gavi's drinking habits, but based on my experience of the cars/engines he's talking about, I tend to believe him...
...though the glorious sound alone more than justifies the fuel burn, imho!
...though the glorious sound alone more than justifies the fuel burn, imho!
cereal tiller
Well-Known Member
A concise explanation indeed.
reducing the oil/petrol ratio can help when using a 2 stroke on light load .
our little yamaha 4 hp gets grumpy if it's petroil mix is stronger than 100 to 1.
the original instructions(1986)state that the mix should be changed to 50 to 1 for commercial or use or continuous high loads,makes sense.
the_wanderer
Well-Known Member
Sounds about right for the Thames.
Hi.
If you are just using the boat inland then no problems. If you want to use the tideway just use the tides to carry you.
I have used a 7.5 Honda for the last thirty odd years on a 14ft boat on the upper Thames and the tideway with no problems. Quite cheap on petrol too, averaging 18-20 mpg. You will not get that with 60 horses.
Regards.
Alan.
Hi.
If you are just using the boat inland then no problems. If you want to use the tideway just use the tides to carry you.
I have used a 7.5 Honda for the last thirty odd years on a 14ft boat on the upper Thames and the tideway with no problems. Quite cheap on petrol too, averaging 18-20 mpg. You will not get that with 60 horses.
Regards.
Alan.
Curry
New Member
My first boat was a wooden rowing boat and you know that was the best one!
Gavi
Well-Known Member
We had a potter around on Sunday and the 60hp was manageable. However, something smaller would definitely be quieter and easier to handle. The whole point of this boat is for her to be something anyone visiting the house can take out. I think we'll look for something smaller, but not as small as oars
Thanks to all for the contributions on this thread.
Thanks to all for the contributions on this thread.
Ramage
Well-Known Member
Speak to Kings Marine at Chertsey..a Yamaha 9.9 should fit the bill. They may even do a p/x on your big old Johnson!
Gavi
Well-Known Member
Speak to Kings Marine at Chertsey..a Yamaha 9.9 should fit the bill. They may even do a p/x on your big old Johnson!
LOL, that's exactly who I had around on Friday to get the Johnson working. They suggested selling the Johnson on eBay as "a runner" and video it running. This is broadly what I was intending to do anyway.
Doolittle
Well-Known Member
Hi Brendan, I traded our 40Hp for a 15Hp 4-stroke Mariner for the school run boat. Best thing I ever did. This will be it's death knell now but it's never let us down in 8 years and used virtually daily!
Initially the 15ft SeaHog Sea Jeep would just about get on the plane when the 15 was new but no chance now. Too much of the prop has worn away!
Steve at Penton had a fair deal for us for the exchange. But I would be inclined to edge towards a 20Hp. Even a 15Hp would get your Broom on the plane though.
Mike
Initially the 15ft SeaHog Sea Jeep would just about get on the plane when the 15 was new but no chance now. Too much of the prop has worn away!
Steve at Penton had a fair deal for us for the exchange. But I would be inclined to edge towards a 20Hp. Even a 15Hp would get your Broom on the plane though.
Mike