Reliability...2 vs. 4 cycle engines

[Capitol Motorbikes]

Glad to hear that some of these 2 strokes last for a long time. I'll be really bummed when mine finally goes to the giant scrapyard in the sky

 

[SirJakesus]

Glad to hear that some of these 2 strokes last for a long time. I'll be really bummed when mine finally goes to the giant scrapyard in the sky

Everything seems really easy to replace on them though. Just because your engine starts losing power doesn't mean the engine is done for. However with their overall low price I'd be very tempted to just buy a replacement engine and swap the two out. Then you know roughly how much time you have to rebuild your old engine before the new one wears out. I have over a thousand miles on my HT kings 80 and it has tons of power. I run 32:1 mix with a fairly rich fuel/air mix. So far the engine has given me no problems. Starts up in the beginning of the season within 30ft of pedaling and I'm off grinning.

 

[Bob the boatbuilder]

Like anything you get what you pay for. I once made the mistake buying 3 Chinese go-peds. It took all three just to keep my kid riding one of them. So much for selling go-peds.

I chose to go Honda, just because the repair parts are obtainable, and I personally have had good luck with Honda products. Is it worth all the extra cost, perhaps not because there are a number of well built motors out there.

 

[Wheres my dog]

SUBARU EHO35

NOT a single issue ever with it on my GEBE setup! On the quiet side as well even at higher speeds!

Did I mention NOT a single issue in many many many hundreds of miles???

 

[5-7HEAVEN]

Chinese vs. Japanese

I sidelined my 4.25 hp GP460 Chinese engine for a 2.8 hp Tanaka 47R engine. The Chinese engine MIGHT be more powerful and quieter. However, its cylinder plating is suspect and its clutch springs break on a regular basis.

Reliability over power (Not that the 47R engine is a slouch, though.)

 

[loquin]

I think that there's four major factors to think about when you're discussing reliability...

1. Even though 4 stroke engines have more parts than two strokes, the fact that they have an oil bath in the crank provides superior lubrication over oil mixed in the fuel... IMO, that more than offsets the 'simplicity of two stroke engines' argument.
2. The second factor is the manufacturer. If you are talking about an established manufacturer like Honda, R/S, Mitsubishi, Tanaka, and the like, these companies have a reputation to uphold. So, to protect that reputation, they have invested in top-notch quality control programs. A program like this isn't cheap, but a good QC program is still cheaper than losing customers to the competition... And, with these companies, IF a defective motor happens to make it out the door, will stand behind their product.
3. The third factor that should be talked about is supporting hardware. What type of mounting hardware is included in a kit? Do the sprockets have hardened teeth? Is the chain made of steel that won't stretch? Is it properly lubricated at the factory? Are any bearings sealed? Are clutch springs tempered correctly? What grade of aluminum is used?
4. The fourth factor is the kit seller - Does the kit seller buy from the lowest bidder? Do they make custom parts for their kits? Does their design allow for tensioning the chain/belt without the use of a separate tensioner? Do they take pride in what they do, or are they out to make a quick buck? Do they stock enough spare parts? Do they stand behind what they sell?

The question of reliability has a lot more to do with the engine manufacturer and the kit seller than it does about 2-stroke or 4-stroke.

 

[kallsop]

The 2 stroke has twice the number of power cycles as the 4 stroke, and although the 4 stroke can be better optimized for cylinder filling and exhaust, the 2 stroke should have the better power to weight ratio, and smaller size. Mixing oil and gas can be a drag, and I'm not aware of any small 2 stroke bike motors that have a separate oil tank and automatic mixing system e.g. Yamaha Autolube.

The China Girl 2 stroke is a sorry excuse for an engine but some are able to make it run for miles without shaking every bolt loose. At higher cost the Mitsubishi and Tanaka are far superior and will last a very long time. On the 4 stroke side, Honda and Robin/Subaru are just as reliable, maybe more, and down on power for the same weight, and expensive. Thatsdax has a bunch of branded engines too.

My experience has been that if you like working on the bike and fixing it, a lot, the China Girl has you covered. If you prefer to ride the bike, all the other options are better. Rear friction roller is the simplest, wears tires faster, more prone to punctures, and arguably looks a bit ugly. An in frame mount plus chain drive has the motorcycle look that many prefer, lowest and most centered center of gravity, more effort to install. Putting a four stroke in the frame usually requires wider cranks.

There is no right or wrong answer, there are many variables and each of us places different value on each.

 

[Oddzball]

I dont claim to know much yet about these motors, HOWEVER even with my 2 stroke motor making funny noises it still drove like a champ 8 miles all the way home.