How to make a China 2-stroke 48cc / 66cc last forever???

Discussion in 'General Questions' started by BillMckraken, Jun 4, 2011.

  1. BillMckraken

    BillMckraken New Member

    So I've seen lots of posts on performance and maxing speed. I'm curious, starting with a brand new china engine 48 or 66cc; what all can be done to make it last forever......well as long as possible? The reliability of these engines, from what I can tell, is scary at best.
    The focus here then, is not more power or final speed, only reliability. I'm not an engine expert nor have I messed with these engines, however some reading online has given me ideas to start the ball rolling.

    - First I assume do all the steps from the Pre-build checklist on this site here. (sorry for broken link)

    - Second replace bearings in the engine, right?
    have found from searching I guess, from what I've read that's figured out. SKF 6202-2RSH Roller bearings (4) and INA K10X14X13-TV or INA KBK10X14X13 or gilardoni 10x14x13 needle bearing for the top connecting rod (credit here )

    - Third, Port the intake and exhaust? I know everyone seems to do this for performance but would it also help reliability?

    Like I said I don't know much here but I think maybe these few things will help? Anyone have any ideas?

  2. RedBaronX

    RedBaronX Member

    I've heard of some of these engines lasting a couple thousand miles when treated right, but that is not going to be the norm
  3. ktjensen

    ktjensen New Member

    This is a great topic. Was also wondering how weather would effect the engine performance if you ran it in winter a lot. Maybe it is warranted to consider alternative small engines to last longer?
  4. Al.Fisherman

    Al.Fisherman Active Member

    "what all can be done to make it last forever" = park it in the garage.
    All kidding aside.. Take your time and build it RIGHT. There are quite a few things that I do as it comes out of the box. Make sure that it is mounted correctly, and I don't mean "looks" correct.
  5. SlugMan

    SlugMan Member

    Well, if your going to purchase a China engine and rebuild it to make it last longer. Why no just buy one that is built correctly. It will cost ya about twice as much, but 'should' perform and last much longer. Check out This guy has traveled to China and found better parts for his engine builds. Looks like the Gumbee engine, but don't let that fool ya. It comes with better bearings, better casting, better carb, intake, etc. You can even get a high compression head and ceramic coated piston (If ya feel the need). The engine is balanced also! Big plus.
    Only downside is he is located in Australia, shipping is a killer :) But, if I ever bought a China engine again, it would be from this guy.
    I've done business with this company before, and they are great!
    This is not a plug, it's only FYI.
  6. RedBaronX

    RedBaronX Member

    well that's the thing, the shipping costs from Australia adds a HUGE amount to the overall cost. I would consider buying an engine like his... if it weren't for the huge extra shipping cost.
  7. Bob Mac

    Bob Mac Member

    What would I do to a ht motor

    I think the #1 thing to do would be to balance the crank. These things vibrate themselves into annihilation.
  8. james65

    james65 Member

    Seems like this Aussie is missing the boat. He should team up with someone like Pirate Cycles and have the engines shipped to them for sale on a commission basis! At least thats the way I think!
  9. ktjensen

    ktjensen New Member

    Yes. Rocksolidengines should just license his source to a distributer in the states. But there might be a problem with importing 2 cycle engines, without that polution-EPA inspection on that specific engine. But that prevents better engines from getting over here.

    Has thinking the Honda engine with the staton drive is a best option. Honda last forever and keeps up a supply chain of parts.
  10. RedBaronX

    RedBaronX Member

    or, someone in the States should do a thorough rebuild treatment... importing Rock Solid rebuilds, even in "bulk", isn't going to keep the price down, might even make the price go up (because each person who touches it will want to make money from it)
  11. dougsr.874

    dougsr.874 Active Member

    What is the point in having an engine last forever? When you can replace it so cheaply.
  12. retromike3

    retromike3 Member

    the point

    the point is when you are in the middle of something or a long way from home and your engine quits.In my case I got to the place I wanted to go and then when I got back to the bike it froze up. I had to take the drive chain off and pedal it back home. I was not a happy camper.

    I would give up some of my horsepower if it was a lot more reliable.

    I usually have a spare engine "just in case" but I don't have one now.

  13. sparky

    sparky Active Member

    (1) Make sure that you use blue loc-tite on all the nuts/bolts.
    (2) Use rubber/leather (old belt?) mounts.
    (3) Plastic intake manifolds are a NO NO!
    (4) Make sure you have a few ignition modules/coils that actually work. My original fell apart, and I tried splicing the wires but couldn't ever find the ground wire?? Got a replacement motor, now that wire is rusted/corroded. I'm trying to replace the ignition coil without a new motor and I just can't find one that works (beyond just light sparking). I ordered 2 from a shop and neither of them worked, while the corroded one at least fired right up. Then somebody recommended I get a weedeater from WalMart that was in X to Z price range. I got the two in that price range and both of them have 54mm clutch drums and the fricking ignition module has different bolt holes!! BOTH OF THEM! They both took a torque screwdriver which took a good while with my awkward multi-tool. I even drove to another Walmart that had the "better" 33cc one in, because it simply wasn't an option at the first two stores. Both had the 54mm clutch drum and different mounting holes and area on the flywheel.

    Long story short....

    Use blue loctite on everything and make sure you can get replacement ignition modules READILY and EASILY. I've been looking for two fricking weeks!!! Three whole days, it seems, dedicated to adjusting non-functioning CDIs and/or disassembling and re-assembling weedeaters that just won't fit. I officially "turned" crazy today.
    Last edited: Jun 6, 2011
  14. ktjensen

    ktjensen New Member

    Now that is a hobby. Good luck getting it all to work. For me it is sounding like I should just get a used motorcycle. Yes more expensive at three times the cost for something good. Then need to read ZEN AND THE ART OF MOTORCYCLE MAINTENANCE.

    Replacement engine is $200 to $300, then have to install it. If I paid someone (not a hobby) then it is $500 all said and done. Most hobbies cost at least $1000 to get started, then $500 every six months to maintain that hobby.
    Last edited: Jun 7, 2011
  15. dougsr.874

    dougsr.874 Active Member

    My best advice is to trash the two stroke garbage from China, a 4 stroke even from China is far superior.
  16. sparky

    sparky Active Member

    I don't have a Chinese 48cc or 66cc motor, so I can't comment on those, since those are what most people will be purchasing.

    My 33cc motor came on my bike and I had a replacement motor/gearbox sent to me.

    My only TRUE problem is the ignition coil, because it's "non-standard" on other 33cc motors of its size. The bolt holes on my coil ignition module are in a line parallel to the flywheel, whereas all the ignition modules I'm seeing have bolt holes that are at a right angle to each other. And... since it's from China, the replacement parts are just as likely to be shoddy.

    Since the motors asked about in the OP actually have a more "advanced" CDI by member Jaguar here, I wouldn't be too concerned about this issue. It's really just my own problem, it seems. But it's h-e-l-l trying to figure out a solution. And when I do, I'll order 3 spares so I won't have to solve it again.
  17. rustycase

    rustycase New Member

    More important to me, than lasting forever, is that it be cost effective.
    Since they are cheep enough, I wouldn't care if I needed to plug in a new motor each year, and recycle the old one.
  18. BillMckraken

    BillMckraken New Member

    I guess at least there have been quite a few suggestions on increasing reliability. It's good to have them all in one thread I suppose. Thanks to all the suggestions!

    For me, I had intended on doing a 4-stroke grubee on one bike and a 2-stroke china on the other. I kind of wanted to see how they both performed, myself. However, after all the research on these; I just can't bring myself to buy something, expecting it to be doomed within 600 miles. I know there are some "good ones" and all these changes mentioned here can also help. I suppose, the lower cost doesn't justify it's lower reliability to me.

    @retromike3 I feel, hope, that most people would be willing to trade a lil' HP for reliability. I feel the same here.

    @dougsr.874 from your earlier post about cheap replacement; I see one main drawback from the "just replace's cheap" Idea. Mainly, if everyone replaces them, the china Mfg and importers just think "wow these are selling great, we don't have to change anything". I bet one chicken egg that if sales on the 2-stroke dried up, they would have a better quality engine imported quickly.
    From your last reply, I totally agree. It seems (from reading) that the 4-stroke is the way to go. I suppose it would probably be cheaper, when looked at after a year or so.

    A note too from grubee's website. I'm not sure now where I saw it; but I did find a warranty importing page on "china gas" (the company mfg'ing for grubee). On that page it stated that the company offered 2 versions; a official "labeled" engine that met US standard AND carried a warranty. The other version shipped blank and was OEM and did NOT meet with US standards for engines and therefore carried no warranty.
    We are getting the OEM engines imported from Grubee so technically there is no warranty unless the seller eats the cost, I suppose. UGH!

    I'm not sure what engine you have, but I assume the 66cc? I believe most of the stores selling kits also sells the coils too. Here's one I found, are these what you need?

    so I guess ultimately it will cost more (4-stroke or some other 2-stroke) to get one going reliably. For me I'm comparing the functionality of these to scooters (e.g. no license, street legalish). Even with the added cost, it seems, comparable to the China scooters; a worthwhile option. At least with the 4-strokes....

  19. sparky

    sparky Active Member

  20. retromike3

    retromike3 Member

    How reliable does need to be?

    I had a crash on my bike on Sunday (major road rash, dinged rib) I needed to get to the hospital on monday. I have a really hard time just walking around lately.(think stabbing pain in front left ribs). So I hopped on my motorbicycle and road it up to the hospital. I road though the suburbs and up some major steep hills and made it to the emergency room on my own. There was no way I could have got there on the light rail or bus and I don't have the funds to pay for a ambulance.

    So now I have about three weeks minimum that I can't ride my road bikes and if I want to be some place then I have to take my motor bicycle. For right now it is reliable enough. I am just going to baby it for now and keep just putting to and from were I need to go. I have in the past gone mostly W.O.T. But I will see how it goes now just above idle.