Why did they give up on two-strokes?
#31
01-24-2014, 11:33 AM
Polaris ATV Expert
Retired and loving it!
Retired and loving it!
Not just the EPA getting into 2 strokes,but look at the strides made into making 4 stroke engines lighter and more competitive. Just a little over 20 pounds difference between a KTM 250 SX and a 450SXF. Not counting all the other makes and what they've been able to do. Just makes sense in getting rid of the 2 strokes imo. Even my sons 85 hp Yamaha outboard engine is way thinner and lighter than those of years past.Plus no oily film on the lakes and air.
#32
01-24-2014, 01:43 PM
Those old 2 strokes in ATVs were not serious 2strokes. They never even had power reed valves.
A 440cc liquid cooled 2 stroke should make between 80-90hp.
Even entry level 440cc fan cooled without reeds made 45-50 hp.
Why does it take a 450 4stroke to compete in a 250cc 2stroke motocross race?
A 4 stroke needs a 200cc displacement advantage to compete.
The 125 2strokes race 250 4strokes in their class as well.
Love to see a new 450 4stroke motocross keep up to a old 2 stroke CR500 Honda , RM500 Suzuki RM , KX500 Kawasaki or YZ490 Yamaha.
Same with outboard Motors, a new 90hp 4stroke has the same bulk/Mass as a 150hp 2stroke outboard.
That's why you well never see a 4 stroke chainsaw. By the time it had enough power to cut down a tree nobody could lift it.
A 440cc liquid cooled 2 stroke should make between 80-90hp.
Even entry level 440cc fan cooled without reeds made 45-50 hp.
Why does it take a 450 4stroke to compete in a 250cc 2stroke motocross race?
A 4 stroke needs a 200cc displacement advantage to compete.
The 125 2strokes race 250 4strokes in their class as well.
Love to see a new 450 4stroke motocross keep up to a old 2 stroke CR500 Honda , RM500 Suzuki RM , KX500 Kawasaki or YZ490 Yamaha.
Same with outboard Motors, a new 90hp 4stroke has the same bulk/Mass as a 150hp 2stroke outboard.
That's why you well never see a 4 stroke chainsaw. By the time it had enough power to cut down a tree nobody could lift it.
#33
01-24-2014, 03:55 PM
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My 4 stroke Honda outboard motor can only be transported in two positions or oil runs from the crank into the valves and its has to sit a long while to start up again.
#34
01-24-2014, 04:10 PM
An other issue with a 4 stroke chainsaw besides power to weight is can a 4 stroke be run at any position or angle like upsidedown?
My 4 stroke Honda outboard motor can only be transported in two positions or oil runs from the crank into the valves and its has to sit a long while to start up again.
My 4 stroke Honda outboard motor can only be transported in two positions or oil runs from the crank into the valves and its has to sit a long while to start up again.
#35
01-26-2014, 01:13 AM
I just dont see a modded 400ex beating a modded 400 scrambler. Dump money in a two stroke 400 and your talking 75+hp without juice. Yeah they might be heavy and dont handle as well as a full blown sport quad, but all I have is a top end pipe and silencer, k&n filter, V-Force reeds, bored .80 over, and a clutch kit. Tore my buddys 660 Raptor in a drag down the road. Would I want to race him on a track? Hell no. The scrambler handles like a tank. Fast in straight line and great for mud.
I am just thinking a twin cylinder, 600cc two stroke atv would be sick. With some cheap mods ( pipe and air setup) it could have some crazy power.
I am just thinking a twin cylinder, 600cc two stroke atv would be sick. With some cheap mods ( pipe and air setup) it could have some crazy power.
#37
01-26-2014, 10:59 AM
#39
01-26-2014, 06:10 PM
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#40
01-28-2014, 07:34 AM
it's so nice not fussing with the 2 stroke- starts easy, zips through thick brush & shrubs effortlessly- it's hardly any heavier than my old 2-stroke weed wacker which was always a total PITA to get & keep running.
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