Life Expectancy of a 4 Stroke Engine

Discussion in '4-Stroke Engines' started by A_FITZ, Nov 9, 2010.

  1. A_FITZ

    A_FITZ Member

    Ok, so I just found out life expectancies of a 2 Stroke Engine on a motorized bike is . . . 600-3000 miles. Some people just reach 1000.

    Mines already having problems.., and I just bought mine premade.

    So I ask you with a humble question.....

    How long have your engines lasted with these 4 strokes..?

    :rambo: I just felt like putting this for some reason.

  2. JunkyardDog

    JunkyardDog Active Member

    In my experience, a 4 stroke engine will last several times as long as a 2 stroke engine, sometimes as much as 10 times longer. On the other hand, the top end on a 2 stroke, if you have the right one, can be quickly, easily, and cheaply rebuilt, while a 4 stroke is much harder, more time consuming, and anything but cheap.

    To make a comparison, I have 2 scooters, both bought new. One is a Yamaha Vino 125 4 stroke. I have 14,000 miles on it, and have not had a single problem. Many people have put over 50,000 miles on these engines before having any problems.

    My other scooter is a Genuine Stella, just bought new a couple of months ago. It is a 150cc 2 stroke, which failed on me at 400 miles. It was repaired under warranty, but according to all the scooter forums I belong to, 8,000-10,000 is the absolute max you can expect from a Stella top end. On the other hand, a new one costs $249, and you are back in business. A Yamaha motor cannot be rebuilt with new parts for what a scooter with 50,000+ miles is worth. You are looking at about $1200 worth of parts.

    For a bicycle motor, considering the low cost, I am definitely going with a 4 stroke, as much for quietness as anything else.

    One more thing. Not all 2 strokes are short lived. I managed to put 20,000 miles on a 50cc Tomos moped, and never even had the head off. It was still running great when I sold it. Build quality and quality of materials used seems to have a lot more to do with how long a 2 stroke lasts than a 4 stroke. My advice is whichever way you go, stay away from anything made in mainland China. 2 stroke or 4 stroke, it's all junk. Jerry.
  3. Old Bob

    Old Bob Member

    I have Honda GX series with over 2000 miles and no signs of significant wear.

    The Honda will out last any other lawn tool four stroke due the centrifugal filter effect from the oil dipper. It slings solids to the walls of the oil tank,only clean oil mist re enters engine.
  4. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor


    Normally I dislike Chinese products, however the HS 142 4-stroke motor is an exception. I have well over 4500 miles on mine and I know of one with over 7000 miles. It seems the biggest issue is finding the correct drive ratios and converting to American made drive systems.

    Have fun,
  5. HeadSmess

    HeadSmess Well-Known Member

    theres fourstrokes over 100 years old that run.
    theres two strokes over 100 years old that still run.

    i still use a 30 year old 2 stroke brushcutter. no reason to get rid of it. thats 2 years older than i am!

    onto my fourth chainsaw(2stroke) in three years.(2 oil pumps dead, one engine dead)

    i had a huasheng fourstroke die for no reason after 500 km... ive got an os26 fourstroke that sat in a pine plantation for years unknown and runs beautifully now...

    its a stupid question that is relative to the observer.

    how much do you pay? how good are you at maintenance? how hard do you use it? how often? what types of fuels, oils are you using? what brand is the engine? is it stock or modified? do you garage it or leave it outside in the rain? what environment are you running it in? do you complain that its useless when something minor like a plug cap fails or a carbie springs a leak because you cant fix it?
    Last edited: Nov 10, 2010
  6. give me vtec

    give me vtec Active Member

    I think he was talking about the ht 2strokes...not 2strokes on general.

    Realistically it depends on who made the engine, how hard you run them, how you break them in, and the oil ratio.

    If all the right circumstances fall into line, you don't excessively abuse them, and you are lucky... You can get thousands of "trouble free" miles. But on the flipside you can also get one that came with a faulty carb and doesn't work out of the box.

    Because of the qc and numerous manufacturers it's almost impossible to say with confidence how long one will last for sure. It's common to see 1000-3000 miles before they seize.

    It basically comes down to "you get what you pay for".

    The ht engines are fun to play with, but I wouldn't reccomend one for daily transportation. If you are going to ride your mb with any regularity buy a rs eho35 powered gebe kit... Its by far and above the best kit out there... As evident by the $600 price tag.
  7. lowracer

    lowracer Member

    I've got a few thousand miles on my Robin E035 & it seems to be getting stronger. I run it WOT all the time. I change the oil every few hundred miles & use Premium gas w/no ethanol.
    So far so good.
    I just got a Lifan 152F 97cc engine yesterday & havent started it yet but will see how it holds up compared to the Robin.
  8. ibdennyak

    ibdennyak Guest

    I'm guessing you will be pleased. I have two of them. I ran one for ~7000 miles give or take until I wrecked it in a snow storm. Always started and ran well. Odd part was that it was laying in the snow when I got to it.....still running.
  9. lowracer

    lowracer Member

    Not to get too far off topic here, but how did you hook up your throttle to the Lifan?
    I started it up for the first time on the grass yesterday after adding oil & gas & it ran at full throttle for a few seconds until I shut it down. I didnt even realize it was on full since I am so used to the little Robin's higher RPM's. The lever throttle came jammed at the fast setting & I had to get it loosened up to get it to slide up to slow. I probably need to drill & cable stop mount for my bicycle cable to operate the throttle somewhere but wanted to see what others have done...(see pic)

    Attached Files:

  10. MikeJ

    MikeJ Member

    Ibdennyak -

    I have been away from this forum for a while. Where did you get the engine plate that is displayed in your photo? I should get one...

  11. ibdennyak

    ibdennyak Guest

    Lowracer....missed your post I guess. the easy way out. I just backed off the tension nut on the hand throttle, and used the existing cable mounting hardware. Worked very well including the governor. At WOT you can feel the governor acting like a cruise control going up and down the hills. Also, it can be over revved to an extent by pulling the throttle more.

    MikeJ, I bought a bunch of off road scooters for the engines, so I had to make my own. I think if you buy just the engine it comes with it. Otherwise.....mine came from Home Depot. It was a Simpson construction part.....1/4 in plate about 8x8 inches. Cost about 12 bucks here....probably about 6 anywhere else. With an angle grinder, drill, and the proper vocabulary they are useful for all sorts of mounting and reinforcement applications. Oooor, in a pinch, they can be used to bolt timbers together. :jester:
  12. lowracer

    lowracer Member

    I mounted the throttle cable before I read your post. Your way would have saved me alot of time & frustration (see pic).
    Do you think the carb can suck the fuel up about a foot if I removed the stock fuel tank & replaced & relocated it to a lower position?
    I think the engine won't look so huge with the tank off the top. Thinking of mounting a Goped tank behind the engine under the air filter?



    Attached Files:

  13. ibdennyak

    ibdennyak Guest

    Noper, most defo not. Ran into the same thing.....remove the tank and it looks like a 50cc. What you need is a pulse carb. Being kind of lazy (on my resumes I phrase it as maxmum utilization of available resources) rather than convert all the linkages etc, I took a pulse pump from a GC something Honda on a pressure washer and plumbed it into the crankcase vent where the tube goes into the air cleaner to reburn the fumes. Then I just hooked up the in and out fuel lines and from there to the carb. Worked fine. I think the engine was like a Honda GC 140 or 160.....4 hp anyway. Another source for a pulse pump is on ebay. Item #140428061906. That one has a little higher volume than the one I used, but a little extra is a good thing. It also has brass nipples. The plastic nipple broke on mine when I wrecked it. That vendor also has a lot of intriguing little goodies that are useable on bike conversions. I'm thinking of their hydraulic brake calipers....pads should last longer than what I am using,'s hydraulic. :idea:

    Hope that helps. If I don't answer your posts just shoot me a PM. I'm in and out quite a bit, and may miss a post sometimes.
  14. Danny3xd

    Danny3xd Member

    "maximum utilization of available resources"

    Har, lol Denny. I am gonna use that on my resume and in my never ending quest of maxmum utilization of available resources. (Like "borrowing" lines, lol)
  15. Zev0

    Zev0 Member

    The pic you are mentioning is not denny's, it's lowracers. You HAVE been away for awhile. :grin5:
    Last edited: Nov 27, 2010
  16. lowracer

    lowracer Member

    Not sure if the engine plate question was for me?
    I mounted the Lifan using some angle iron & flat bar from Lowe's Home Improvement.
    I removed the metal foot plate that came on the Lifan & inserted (2) 1/2" thick heavy rubber skateboard riser pads between the engine & the mount for both vibration & to raise it up slightly to clear the bolt heads. Working out real well...(see pics)

    Attached Files:

  17. loquin

    loquin Active Member

    FYI - I believe Walbro (among others) makes an add-on diaphram fuel pump for single cylinder engines. With it, you should be able to relocate the fuel tank up to several feet below the carb...
  18. Old Bob

    Old Bob Member

    Yes walbro makes a pump.
  19. chrisnbush

    chrisnbush Member

    If Hua Sheng "dies" suddenly, check OHV

    Just noticed this. I had mine die, took the carb off as I was getting spark, etc. etc.

    Finally out of desperation, removed OHV cover, I had adjusted the valves at one point, though I might have messed something up.

    What happened is the pin that the valve rocker sits on had corkscrewed out, dropping the input rocker. So the input valve wouldn't open which is certainly an engine killer.

    I now have a little block of wood pressed in holding a piece of metal against where the pin slides out, so it won't.

    IF a HuaSheng dies suddenly, this can be one of the reasons. Heads up



  20. HeadSmess

    HeadSmess Well-Known Member

    aye....the huashengs strangely running again...

    i stripped it completely, found nothing wrong....started back up, was still bad!

    so i left it spluttering away for about 3litres of fuel.... and now its fine again?

    my verdict?

    i had the valve clearance to tight. (threw me cus it was fine for at least a week after adjusting) then the ex valve coked up, preventing a complete seal.
    then, when i stripped it...i just guessed the clearances on re assembly. loose! so the carbon on the seat must have been bashed and burnt off eventually with some running.

    cus its like new again.... and i have been prodding my braIN FOR ANSWERS! and other ppls brains! even me mate, a 70yr old mechanic is bamboozled!

    it runs...all good. bye bye 2strokes!