Please keep in mind, this is just my opinion and I humbly offer it without a desire to get my butt shot off:
Liquid cooled scooters (below 400cc) are simply a maintenance nightmare awaiting ownership. There is far too large a percentage of 250cc liquid cooled scooters that have problems with liquid cooling within the first 1K miles. Liquid cooling probably leads to longer life of engines, but the cooling system itself is prone to problems. The ports and coolant flow regions just aren't large enough to allow for efficiencies without corrosion or clogging jumping into the game too soon.
My rule of thumb for motorcycles was always to look for liquid cooled above 500cc, and air cooled below that size. Of course V-Twins are a different game, but my other rule of thumb has been to avoid air cooled V-Twins altogether.
But there are plenty of satisfied liquid cooled scooter customers out there.
Good topic sillywilly. I thought of swapping out my 150cc for a 250cc but the plumbing seemed a little intimidating. I never knew there was a 50% success rate from the manufacturer . I hope we get detailed responses complete with worse case scenarios.
I have never had a problem with air cooled bikes from ITs off road, to street bikes in hot Tennessee weather. I like the forced air cooling on my new 150 scoot. Seems to work great. Plus air in the crank case is better than watter in the crank case. As stated above, just my opinion and some experience. I hope the 250s do better than my Fords and Chebys concering cooling system problems.
2011 White Burgman 400 ABS 6,000 grins.
JCL MP-250A 257cc 25,000 (s)miles with an average of 73MPG
Tank style Racer 150. 15,000 US (s)miles. (sold $500.00)
I have the Linhia 300 (275cc) Liquid cooled, when I first received my scooter I had to flush the radiator and replace the coolant. It took a little effort to burp the system, I have not had any trouble since. During the summer heat, I doubt my scooter would have survived if it was not liquid cooled.
I had inquired about the Lance 250cc Duke at the dealer I bought our Lance 150cc Duke from and he said he would not handle the 250cc because of cooling problems with it. The radiator was in back of the gas tank and proper airflow was almost blocked from the radiator. We ride double and are full sized adults so the extra power of the 250 would have been welcome. He thought Lance was coming out with an improved model of the 250 we should wait for.
Hi All, Actually liquid cooling allows an engine to run a leaner mix. Liquid cooling is more efficient at disipating heat, BUT it does so at an increase in complexity and cost of production. In a low cost scooter I would shy away from liquid cooling. On a higher cost machine where the engineering and parts quality is there I would not. My 150 is an air cooled machine. I have run it in summer heat with no issues. My BV500 is liquid cooled it too has been run in warm weather. It too ran well. The difference is what I paid for the one verses the other.
The immediate answer to the question is that liquid cooling is more efficient, air cooling is much simpler and requires much less engineering and fewer parts.
The problems most have had with the liquid cooled Chinese scooters are pretty much caused by garbage coolant from the factory, seems that it is not much of a coolant in the first place, and tend to cause corrosion in the cooling systems. Most folks avoid such trouble by doing a THOROUGH flush and swap with GOOD coolant. Actual incidence of this type of trouble has practically disappeared among the dawgs, they have all take the PDI seriously and done the proper set up.
New folks do show up with the trouble sometimes, and those folks have not done any research about the known issues before they are experienced.
As to the 244cc and 257cc engines, there is nothing at all wrong with the designs, and the Chinese do a decent job of building them. Engines do not seem to be a source of trouble. Components are the problems most times.
To me, the biggest the engine the more it needs to be liquid cooled, but that is just my opinion, big bikes have been built for decades with air cooled systems.
Last Edit: Nov 2, 2008 21:30:12 GMT -5 by poohbear
My scooter is water cooled (250B), and I did have problems with the 1st cooling system service. Took some effort to get system working again, nasty air pockets. But since them seems to be ok. Not sure how well the motor would hold up at high speeds trapped in a plastic cage, with little ventilation. My wifes 150 is air cooled and runs great at all speed up to 50+mph. I am thinking a 250 could survive without water cooling if properly air cooled. Scooters with there covered and enclosed motors build up heat fast. When it works right water cooling an engine is very effective at limiting engine damage due to heat, and maintaining the engine at a specified temperature range. Downside is increased maintenace requirements and cost for various parts. I'd rather have water cooling on my 250, than not have it. Reading the prior posts on Lances having the radiator behind the gas tank.....what were they thinking. Whole idea of the radiator is the removal of heat from your cooling system as air flows hits the radiator. Unless they have some sort of elaborate air routing, this cant work very well.
Folks, what are your experiences with the 244cc and the 257cc engines out there?
i own a 244cc liquid cooled scooter. the cooling system on this scoot has been a genuine PITA. i think i have finally got a handle on the problem though. the cooling capacity is too small and the design is inadequate. i've installed a larger radiator but due to variator problems (i need new rollers) i haven't been able to really stress test the modifications i've made. it should be noted that my scoot was discontinued because of the cooling system design, so i heard anyway.
my advice to you is to steer clear of liquid cooled 244cc engines unless you are prepared to tackle the problems associated with the cooling system. also be aware that not all 244cc bikes suffer from cooling system problems.
the bike itself is a fine machine, the frame is solid, the engine is stout and robust. as you can see in my signature i've put over 3700 miles on mine since january of this year.
OK, liquid cooling versus air cooling. Air cooling, simplicity as it is a more simple design, with less parts and less complexity. But air cooling requires the engine to run more rich and with more loose tolerances on the mechanical parts. A air cooled engine has a much greater range of operating temperatures. Usually a air cooled engine temperature runs from the ambient temperature up to over 300 degrees. On a hot summer day a motorcycle, without forced air cooling, can approach 375 degrees F. at a stop light. Ambient temperatures mean just that, in the winter the temps can be below freezing. So they have to allow for the larger temperature range with more loose parts tolerances.
Liquid cooling. More complex design. More parts. More expensive. But the engine operates at a more narrow temperature range, at once warmed up good, at a more constant temperature. So they can run much tighter tolerances on the engine parts. The temperature range runs from ambient to just a little above the temperature thermostat setting of about 160 to 190 degrees F. Because of the better engine tolerances, a liquid cooled engine can develop more power than the equivalent air cooled engine.
Currently, there is a push for engines to emit less pollutants and greenhouse gases. So engines need to run much more lean air fuel mixture ratios. In order to meet these new requirements EFI (electronic fuel injection) systems are needed, along with sensors, so that the ECU (electronic control unit) can more precisely control the engine at all speeds and loads and temperatures. Lean burning means more heat which means a air cooled engine can't meet the stringent requirements anymore. So we will start to see liquid cooled engines more and more, as air cooled engines are obsoleted.
Interestingly enough the earliest gasoline powered internal combustion engines were all water cooled. Air cooled engines came along later.
2007 Roketa Fiji 150 2007 Roketa MC54-250B 1992 Harley Sportster 1200 ----------------------------------- "Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming -- WOW--What a ride!!!"
EarlWB nailed it. Based on my experience with small aircraft engines I'll add that air cooled engines use a part of their fuel for cooling along with air and the oil. Air cooled engine cylinder assemblies are also larger and heavier because of the need for cooling fins, but less complex to build because the is no water jacket. Over all, an installed air cooled engine system will be lighter than a water cooled system once the radiator, water and other stuff is added in. As was stated before, they run at higher temp extremes and thus have more expansion and contraction related issues, more wear and a shorter life.
Because a water cooled engine operates, once warmed up, at a fairly constant temperature the wear is much less. With proper setup and maintenance, including frequent oil changes, a water cooled engine should outlast an air cooled engine by a wide margin.
A bad system design is not the fault of the engine; it is the fault of the engineer. I seen both air and water cooled systems have issues from poor heat management. As Jim63 stated, "what were they thinking," comes to mind.
And, to summarize along the lines of what PreachP stated, an air cooled engine will be less complex and cheaper than a water cooled engine, but will probably have less power, lower MPG and not last as long.
I certainly hope I got all that right.
2008 MC-54-250B - a "real" B! Broken odometer = No maintenance!
both are air cooled, hydrogen oxygen, radiator (fins).
water cooled closer tolerances, quieter. more hp. less detonation.
the oil takes a beating in air cooled engines it fries almost. change is very important.
the design of water cooled scooter engines depend on a decent fan to move air, if the bikes that have the gas tank in front of the radiator had dual fans they probably would cool better. or close in the gaps around the radiator so air could ram into the area.
ive wanted to try to get rid of the fan, (less electrical load) and hook a shroud around the radiator and let the variator fan pull air thru the radiator (pretty high rpm fan) the connection would need to be flexible cause the engine moves, but alas the belt would probably not last long enough with the heat coming thru the cvt housing. but who knows. engine fan cooling on a water cooled scooter.
but yes water cooling, air cooling both have their place.
Nst had an ad for their 250cc engine, it was called air cooled. (translation for air cooling thru radiator, ha!) it had the cfmoto style engine.
gotta love air cooled engines.
occasionally my vw beatle was water cooled, i would turn the water hose on and put water thru the fan housing and wash the engine. rev it up and would the water fly out. i disconnected the heator hoses so the heat exchangers wouldnt fogg the inside of the car up.
kept that engine clean. didnt hurt it one bit.
roketa bali, MC-13-250. 12990 miles, 6990 miles on front michelin "Bopper", 990 miles on new rear "bopper" old rear "bopper" lasted 6000 miles. cfmoto 244cc, ubuntu 9.04
My '84 Honda Elite 125 is liquid cooled, with 13532 miles on it, a few coolant flushes, no problems, no leaks. It rarely gets hot enough for the electric fan to kick on.
It doesn't matter if it is my Scooters, or my Harley. I just like to ride... '08 Harley Ultra Classic '07 Kymco People S 250 '10 Kymco Xciting 500Ri ABS '09 Ice Bear Trike PST 150-11 '84 Honda Elite 125
I like the liquid cooling because it is such a small engine @250 cc for running up into the foothills in the heat. I would want to handle hot air flow and I feel that air cooled would not make the motor last but I have no experience.
I will now look for complaints on the cooling systems before I buy.
Post by qwertydude on Feb 19, 2011 16:37:04 GMT -5
It's an engine's design, not liquid cooling that makes it durable and even up to a limit, powerful. A Honda Rebel has an engine that's considered bulletproof, lots of stories of over 50,000 miles and I rode one through 115 degree heat stop and traffic without overheating. The Rebel is 233cc's and faster than any 250cc scooter. I never am afraid of pushing my air cooled engines, I currently ride a hyosung GT250R air cooled high performance v-twin, almost as powerful as a Ninja 250 which is liquid cooled. Again it's been through 100+ degree stop and go heat without problems.
Remember to an air cooled engine the difference between 70 degree heat and 100 degree heat is negligible compared to an average 250 degree running temperature. Just because YOU are uncomfortable doesn't mean your engine is, I laugh every time I hear Floridians think 90 degrees and 100% humidity are tough on their bikes, no it's just uncomfortable for you. Your bike will do just fine same as 90 degree and 0% humidity which is actually not too bad, in fact high humidity removes heat even better than low humidity. Just use a quality oil that won't degrade at higher running temperatures and you could run in the hottest desert til you pass out and the engine will still be going strong. I know because I rode in a ride where people were nearly passing out cause it was so hot, not a single air cooled bike was close to failure.
The one thing I would worry about is on scooters the belt may be prone to failure should it get too hot, rubber and heat can only tolerate so much, kinda like a underinflated tire that overheats and delaminates. Same could happen to a belt without proper cooling. Again motorcycles aren't subject to this mode of failure.
Last Edit: Feb 19, 2011 16:39:47 GMT -5 by qwertydude
Okay, I'm nowhere near any kind of expert. All I know is in my experienced riders MSF class, the coaches asked if anyone's bike was air-cooled. I was one they specifically asked, being the only scooterer there. They explained that if you sit and idle a lot, you should turn off your air-cooled bike to avoid the chance of over-heating.
Now of course, in an MSF class, there's LOTS of idling going on. But then again, if you're riding somewhere with horrid traffic and you have to idle a lot, then maybe liquid-cooled would be the better choice.
2005 Canyon Red Piaggio BV200 1992 Seafoam Green Taurus LX wagon
Post by qwertydude on Feb 19, 2011 22:47:56 GMT -5
Air cooled scooters are different they can idle all day long because they are forced air cooled, that's what makes them such marvelous city vehicles. Air cooled motorcycles on the other hand can suffer from overheating due to excessive idling. You usually get plenty of warning though, you'll feel absolutely massive amounts of heat rising from the engine and the shifting will get really notchy. Those are the beginning signs, then if your idle starts dropping to lower rpm's you're in trouble. I've been in Las Vegas packed stop and go traffic in 115 heat with my Honda Rebel, nowhere near full overheating. Harley's on the other hand are the ones most likely to suffer. They have high compression and generally poor cooling systems and twin cam engines are especially prone to overheating. Most other bikes I personally could never see overheating in all but the worst conditions that most people, except the hardcore riders, simply don't ride in.
Post by larry001964 on Feb 19, 2011 23:11:40 GMT -5
I had a KZ 550 that was 4 cyl, air cooled, seldom gave me the smallest bit of trouble. Turned the odometer over three times and was half way to the forth before it died.
Perhaps water cooled has its advantages, but air cooled engines are simpler than liquid cooled, simpler to maintain, and lighter weight ( the Navy used radial engines for just that reason for a very long time ). Personally Ive never had a problem with an air cooled engine ever overheating, I'm not saying they can't or aren't more susceptible to it, I have just never had it happen. So Ill keep them..
Water cooling is fine for boat motors, since you shouldn't run out of water. But they still have problems with water leaking into the lower drive gears, etc.
Early cars had water-cooling, but no water-pump. They used a thermo-siphon system that worked fairly well......just keep moving.
Motorcycle-engines can run almost forever....with air cooling and the proper design. The CB750 Honda engine is an example.
Our scooters need a forced-air cooling because of the design......the engine is tucked away under panels. The system works well enough that water-cooling can be avoided completely. Who need the added complication of water-cooling if it is not necessary? It adds greatly to the cost and maintenance of these small scooters, without adding enough benefit to justify the added complication.
If you're not racing, who needs the extra (maybe 20%) power a water-cooled engine might have? Longevity.....I estimate 99% of all 2-wheelers will last just as long if their engines are air-cooled...the stupid V-twin designs being the exception.
The higher the specific output the greater the need for LC. 150cc GY6's are pushing perhaps 8hp, a 100cc 20hp two stroke has a much greater need for cooling. When you start to tune a high end 2T scooter AC will hold you back.
^^^^There are other things under the panels effected by heat, than the engine. The exhaust temperature is similar whether air or water-cooled. The carb for instance benefits from some airflow.....the stock systems have a little rubber hose blowing air at the bottom of the carb for cooling purposes.
A little added airflow is easy enough to achieve......even water-cooled scoots (with a carb) could benefit from such a mod.
Oh.....My '71 H1 500cc Kawasaki wasn't hindered by air-cooling. Stock it had about 60HP. With a few mods it went maybe 75HP. There was also a 750 air-cooled 2-T Kawasaki....even more powerful. Water-cooling to me......simply bling on a street bike.
Last Edit: Feb 20, 2011 8:29:49 GMT -5 by Bluefront
wereed: HOw can I start a thread?
Jun 1, 2013 10:55:49 GMT -5
wereed: or respond to a thread I started three years ago...
Jun 1, 2013 10:56:07 GMT -5
marklorenzi: I just bought one of the Fleetwoods. They look like a clone of the Honda XRM's they sell overseas. It is in transit now and I should get it this week. I will try to post my experience here. Call me the guinea pig hahaha.
Jun 2, 2013 20:29:11 GMT -5
flyangler: wereed, this forum is read only the new forum is on the banner above. Dan
Jun 5, 2013 7:35:29 GMT -5
silkyg1973: can someone please tell me how to post
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