Frogslayer
Well-Known Member
Only if jetted right.
Why does everyone hate 4-stroke bikes?
- Thread starter Will'smotobikes19
- Start date
really depends on the oil, mix ratio, as well as engine RPM.
most lower-end 2 cycle oil doesn't burn as clean and will clog up the converter, as well as produce more smoke (particularly if cold)
in my experience, Amsoil intercepter tends to burn cleaner and doesn't smoke up a lot when cold, for reference i use 40:1 when i premix it, and just pour it in the oil tank on the snowmobile, so like 32:1?
and at 14$ a qt it won't kill ya too bad.
if you keep the engine low and cold, it won't heat up the converter enough. but if it's in higher rpm it gets hot and burns it off good.
most lower-end 2 cycle oil doesn't burn as clean and will clog up the converter, as well as produce more smoke (particularly if cold)
in my experience, Amsoil intercepter tends to burn cleaner and doesn't smoke up a lot when cold, for reference i use 40:1 when i premix it, and just pour it in the oil tank on the snowmobile, so like 32:1?
and at 14$ a qt it won't kill ya too bad.
if you keep the engine low and cold, it won't heat up the converter enough. but if it's in higher rpm it gets hot and burns it off good.
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Great thread! I just bought a Huffy cranberry cruiser for a new bike build. I had built a two stroke kit bike a year ago. My problem
was I chose the wrong bike for a candidate. That was my reason for buying the Huffy. My plan has been to just transfer the kit from
my ole build to this one. But I got to thinking about a 4 stroke. The more I thought the more I wanted one. I went down & bought
a 79 cc predator for this build. I know there not legal but I ordered a 49cc sticker for it. Any way it is in the works now. I,m making
my own jack plate & motor mount. That the great thing about being a retired tool & die maker with a small machine shop. I,m doing
some port work & milled to head & making a new exhaust & intake manifold for a 19mm carb with 22lb valve springs. That should
put it around 5 to 6 HP. Plenty of power for 40 or so MPH. It should be very reliable over any china two stroke with out the vibration
& noise. A few drops of oil to the clutch after each ride & it should last a long time with little trouble. Oh I also added 3 spoke mag
wheels & disc brakes (no broken spokes).
Fly
was I chose the wrong bike for a candidate. That was my reason for buying the Huffy. My plan has been to just transfer the kit from
my ole build to this one. But I got to thinking about a 4 stroke. The more I thought the more I wanted one. I went down & bought
a 79 cc predator for this build. I know there not legal but I ordered a 49cc sticker for it. Any way it is in the works now. I,m making
my own jack plate & motor mount. That the great thing about being a retired tool & die maker with a small machine shop. I,m doing
some port work & milled to head & making a new exhaust & intake manifold for a 19mm carb with 22lb valve springs. That should
put it around 5 to 6 HP. Plenty of power for 40 or so MPH. It should be very reliable over any china two stroke with out the vibration
& noise. A few drops of oil to the clutch after each ride & it should last a long time with little trouble. Oh I also added 3 spoke mag
wheels & disc brakes (no broken spokes).
Fly
Will'smotobikes19
Well-Known Member
Just changed my oil. How about 8.8 ounces of 4 stroke oil a change at $2.95 a QT every 250-300 miles. You could do 3 nearly 4 oil changes for $2.95 and still have some left. Somewhere between 750 and 1000 miles worth of oil. If the pricey oil is to increase engine life it will still be wearing basically the same with pump gas correct me if I'm wrong. When I had a 2 stroke I used some green Motul oil which smelled like bubblegum it was like $20 for the bottle. Another reason I like 4 strokes is you don't have oil dripping all over your garage after a 2 stroke bike ride unless a gasket is leaking. At 4 or so ounces a gallon you have 8 gallons of gas. But how many gallons would the 4 stroke oil last in 750 miles?
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Will'smotobikes19
Well-Known Member
79cc is ok but you may have some clutch issues and it weighs 22.5 lbs the 49cc weighs 11.4. I had a 79cc bike and I didn't like it much. They go 30ish but for less weight and better oil/fuel savings you can have the same speed with a 49cc. Just my 2 cents. Cast aluminum rods don't like high rpm. I haven't seen a 79cc rod break but it's possible. I know the 49cc rod can shatter. I saw a high performance 79cc and his flywheel magnet shattered surprisingly it wasn't the flywheel.
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Frogslayer
Well-Known Member
Should we do a little math while no one is looking Will. If you're guessing 100mpg that would be 7.5 gallons.
Will'smotobikes19
Well-Known Member
Overall running expense should still be less $. Have to figure most 2 strokers use high test gas as well as the expensive oil. Most 4 strokes run fine on 87 and have little tuning issues. The 20 or so CC difference is enough to have better mpg as well. 49cc will run 7 minutes on just the bowl gas and the valve off. The wide cranks aren't even that bad if you have it hooked up right alignment is key. With a mid 30's power plant you really don't need 7 pedal gears either way.
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Frogslayer
Well-Known Member
Maybe, a negligible amount though. Mostly because both types are very fuel efficient.
Well I did my math & I will be running my predator around 5000 rpm. They can handle alot more rpms but I,m
not building this for racing. As I posted in my first post this engine should be putting out 5 to 6 hp at 5000 rpm.
with my final gear ratio I,m expecting 40 or so mph. Thats fast enough for me. If I want to go faster I have a 1300 cc
chopper to clime on.
not building this for racing. As I posted in my first post this engine should be putting out 5 to 6 hp at 5000 rpm.
with my final gear ratio I,m expecting 40 or so mph. Thats fast enough for me. If I want to go faster I have a 1300 cc
chopper to clime on.
When?
Technically they dont meet CARB or EPA emissions and are already illegal for on road use...
Two strokes have the better power to weight ratio, and better acceleration. Also low cost and simplicity on their side.
Four strokes have the low noise , greater fuel efficiency, lower emissions, and higher torque usually. Engines are far more complex.
There are high quality 2 strokes that meet EPA.....like the Zenoah. As well as high quality chainsaw engines from several manufacturers like Stihl snd Husky. I've been kind of wondering why you don't see more $$$ chainsaw engines converted..... The reason must be price. They can turn high rpm, 9000-12000 and make a lot of horsepower in a small size. Made to be used hard, at full throttle, and made to last. Of course they drink the fuel to go with it. A 53cc husky makes about 3.5 hp. Thats waayyy more than a Honda 50cc.
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