Any betta 4 stroke engines on the horizon?

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mifletz

Member
Aug 25, 2009
86
0
6
israel
4-strokes are quieter and smokeless compared to 2 strokes.

But are there any technological improvements/new models on the horizon that will make eg a Robin 35 even quieter, as it's still quite noisy and attracts attention, and to raise its power from 1.6 to 2.0/2.2hp?

Or is it not technically feasible at this time?
 

rohmell

Active Member
Jun 2, 2010
1,531
6
38
New York
I think with the EPA / CARB requirements for cleaner engines, more and more will come with carburetors that are not adjustable, or else had had their adjustments set at the factory, then expoxied shut, not allowing the end user to fine-tune their engine for optimum operating based on their temperature, altitude, etc.
Engines with plastic cams, sintered gears.
I feel that if anything, engines on the horizon are going to get lousier, not better.
 

bandito

New Member
May 22, 2009
783
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colorado
H/S Titan is just as quiet as the soobie and its 49ccs, more power. Only time my r/s is loud is wot or under load like going up a hill.
 

bluedogeli

New Member
May 13, 2009
5
0
0
ca.
Look at Greybeards post, Found something interesting, on pg. 6. It is a shindawa C-4 four cycle hybrid. Go to the site he has posted and there is a computer generated functioning model to look at. Totally cool little engine. Looks like its gonna fit bike application perfect.
 

Dan

Staff
May 25, 2008
12,765
115
48
59
Moosylvania
Man I wanna try that engine. http://www.bransontractorsouth.com/page6.html

I have only seen pics and schematics but does not seem to have a keyed shaft. That is a challenge all in it self.

But is light and small (relativity. the one I want is 79cc) and sounds awesome. I dunno about loud, am meaning the actual sound of it over normal 2 smokes.

http://www.hybrid4engine.com/listen.asp


LOL, I was talking to Carol about this and before I finished she looked at me and said; "So it's a 3 stroke" Cracked me up.
 
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5-7HEAVEN

Well-Known Member
Aug 2, 2008
2,661
240
63
4-strokes are quieter and smokeless compared to 2 strokes.

But are there any technological improvements/new models on the horizon that will make eg a Robin 35 even quieter, as it's still quite noisy and attracts attention, and to raise its power from 1.6 to 2.0/2.2hp?

Or is it not technically feasible at this time?
Noise and smoking 2-strokes are relative and need to be put into perspective.

My Robin/Subaru was quieter than my Mitsubishi TLE43 2.2hp engine, altho the Mits was pretty quiet.

My Tanaka 47R is loud compared to my Mits TLE43, but nowhere as loud as Harley Davidson motorcycles or the local modified mopeds.

My CY460 was pretty smokey, using 25:1 fuel/oil ratio.

My Tanaka 47R is almost smokeless, especially with 100:1 Opti-2 oil.