Could I expect to do 20 mph for like 3 hours?
4-stroke engines quieter?
- Thread starter How2
- Start date
Could I expect to do 20 mph for like 3 hours?
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duivendyk
Guest
That is quite true,if you are looking for cost-efficient transportation the 4 stroke engines come out ahead,but don't undersize the engine,in terms of overall economy a quality 4 stroke, the 49 cc Honda although more expensive and on the bulky side, is a good choice.I don't know about the 49 cc 4 stroke DAX, a Honda clone and a dark horse as far as I'm concerned. It's not a question of design it's a question of quality of materials & manufacturing tolerances.Best fuel economy is usually achieved at around 75% load.Another reason for not skimping on displacement.
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HoughMade
Guest
I've done an hour at 25 with my Honda...I see no reason why it coudn't go longer.
Mountainman
Active Member
How2 -- before I became known as Mountainman -- I was Cityboy -- a long time ago --- anyway back then my friends and I had many small motorcycles --- one Honda 50cc I would take out on all day rides up to Julian -- a town high up in the mountains of southern Calif.. Round trip was approx. 100 miles. I think that little Honda would have made it to New York from here --- remembering at times to ease up a little on engines - letting the oil circulate - a little cool air - hopefully a slight drop in temperature - and especially when breaking engines in - varying of moderate throttle speed - and some important cooling off periods.. Happy Riding from Mountainman
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cruiser66
Guest
Another maintenance item that I have seen mentioned throughout the forums is the repair of motor mounts and broken bolts - a problem which is prevalent with 2 strokes. I have yet to run across any posts regarding this problem with 4 strokes. The higher frequency vibes of the 2 strokes (HT) apparently cause more metal fatigue....
66
66
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duivendyk
Guest
I think it is more a question of inferior materials,that seems to be the pervasive problem with the HT engines.Never had those kind problems with other 2 strokes and I have had many over the years.
Terminal Velocity
Member
I hear all of this talk about not running wot or at high rpm's and then you see stuff about actual speed. Is it possible to put this in terms that aren't variable from bike to bike based on gear ratio (speed)? For example, my bike is geared so that (as measured from a tach) that 30 MPH is about 6000 rpm's. I suspect that is considered high rpm's, but, correct me if i'm wrong, not everyone can achieve this if they haven't been geared for it. so the questoin is: What is considered high rpm's? TO fuel the conversation further, how long can you expect a 4 stroke to last at high rpms? Anyway, this has been an informative post thus far and has been touching upon some issues i've been thinking about.
I am concerned about excessive engine wear/problems as a result of running wot. Dave staton replied to this concern in an email and said that it could be run at wot w/o problems...I didn't believe him. That being said, unless I source a larger gear box sprocket, i will be running at 6000ish rpm's for about 1.5 hours every day twice a day once september starts. 100 mile round trip commute.
I am concerned about excessive engine wear/problems as a result of running wot. Dave staton replied to this concern in an email and said that it could be run at wot w/o problems...I didn't believe him. That being said, unless I source a larger gear box sprocket, i will be running at 6000ish rpm's for about 1.5 hours every day twice a day once september starts. 100 mile round trip commute.
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duivendyk
Guest
I am afraid there are no hard&fast rules,a great deal depends on the quality of the engine and the conditions under which it operates.I would certainly not run any engine at max output routinely unless I was in the racing business.Max output means WOT at high rpm.In my book high rpm is faster than 80% of the speed at which the engine develops max. power, anything above the max power speed I would deem to be excessive and definitely to be avoided.If you end op running above this speed at still at PART throttle your gearing is too low and needs to be changed (less reduction)
Engines vary widely in life expectancy,component quality , operating temp. and lubrication (or the lack of it) are key factors,in this regard the forced air cooled engines shine,high temp. results in oil breakdown and accelerated wear.Use of synthetic oil along with frequent oil changes are inexpensive ways to combat this.These are after all tiny HIGHLY stressed engines.Any Japanese engine I know of is well engineered and built with excellent quality control.The Japanese are extremely quality conscious and demanding as consumers.But any engine can be abused and routinely running it at close to max.power is just that.Most car engines run normally at less than 40% of max rpm or power output.That's why they last. As far as the type of engine is concerned,I think 2 strokes hold something of an edge,mainly because of their inherent design symplicity.Chinese engines are suspect, unless their provenance is well established.In my opinion the Chinese make crummy junk for the export market.I would derate any of them by 50% or more,(limit throttle opening), which of course nobody does.As far as your initial query is concerned ,If you are running at full throttle and 6000 rpm,reducing your gear ratio would reduce your rpm and speed some,depending on the torque characteristic of your engine of which I know nothing.But it does not fundamentaly change the situation,you are pushing the envelope as far as I'm concerned and I would limit my speed to 25 mph or lower, then it would take you close to 2 hrs,or else get a more capable (larger) engine.Good luck,it will be an interesting experiment.
Engines vary widely in life expectancy,component quality , operating temp. and lubrication (or the lack of it) are key factors,in this regard the forced air cooled engines shine,high temp. results in oil breakdown and accelerated wear.Use of synthetic oil along with frequent oil changes are inexpensive ways to combat this.These are after all tiny HIGHLY stressed engines.Any Japanese engine I know of is well engineered and built with excellent quality control.The Japanese are extremely quality conscious and demanding as consumers.But any engine can be abused and routinely running it at close to max.power is just that.Most car engines run normally at less than 40% of max rpm or power output.That's why they last. As far as the type of engine is concerned,I think 2 strokes hold something of an edge,mainly because of their inherent design symplicity.Chinese engines are suspect, unless their provenance is well established.In my opinion the Chinese make crummy junk for the export market.I would derate any of them by 50% or more,(limit throttle opening), which of course nobody does.As far as your initial query is concerned ,If you are running at full throttle and 6000 rpm,reducing your gear ratio would reduce your rpm and speed some,depending on the torque characteristic of your engine of which I know nothing.But it does not fundamentaly change the situation,you are pushing the envelope as far as I'm concerned and I would limit my speed to 25 mph or lower, then it would take you close to 2 hrs,or else get a more capable (larger) engine.Good luck,it will be an interesting experiment.
loquin
Well-Known Member
Small Hondas & Suburus are spec'ed at max torque @ 5500/5000 RPM, respectively. And, both are HP rated @ 7000 RPM.
