Which is the best 80cc engine kit

Discussion in 'General Questions' started by Randy Garrity, Sep 1, 2016.

  1. Randy Garrity

    Randy Garrity New Member

    I am a seasoned dirt bike rider and racer.And with years of experience working on my bikes and engines.As well many other types engines.Since this is the case.Im after a top quality setup.Meaning I am afraid to buy any of these china produced kits.Or engines.When I already well know from past experience.China produces crap overall.I will say the 150cc 4 stroke engine that came in a small offroad buggy I paid 2 grand for.Was a quality engine.Being a Honda clone. Once I took it apart to do many performance mods.Anyways to my point.Does anyone know the true cc size?When all these engine kits state 66/80cc and there is not a engine of such a rating.There all of one cc rating period.Which tells me these are sadly a 66cc giving the buyer hopes of owning a true 80cc. Which would also explain the poor hp rating of only 2hp. When any quality 2 stroke engine will have a lot more hp than 2hp! No doubt about it. I also noticed the same issues with the high performance crap.Because in order to have a true port job or ported parts.You must have the cylinder and the piston both ported in order to be a top quality and proper working port job.Thats before the right type of port work for the riding you so do.Meaning a full range or low end etc. And that takes years of serious experience found at race tracks and race mechanics. I also know the importance of engine balancing any engine that is not.Will simply kill itself with time.Every engine must be balanced or its junk to start with.Then the kehin styled carb ?What in the hell does that mean?Is it a true replica of a Kehin carb?The bottom line is this.That company makes a good carb.However, for these smaller engines.The two best would be a walbro if made large enough to work on a true 80cc I cant tell you at this point.OR a mikuni carb which simply cant be beat for any motorcycle engine period.I ran these on both 2 strokes and big 74 inch Harleys with excellent results! My plan was to purchase the 80cc and then go to work making it a top performing engine.With a good port job and balancing and most likely milled stock head. OR thinner base and head gaskets.Till I gave serious thought about the real quality of the engine and all my work and added $$.I'm not so sure its at all worth it.Because of the quality of the engines internal parts.Starting with the bearings and rod and piston .Which is all there is less a flywheel and crank. So what can you tell me about any of this? Thankyou Randy

  2. FurryOnTheInside

    FurryOnTheInside Active Member

    Welcome and please keep browsing and reading the forum. There's more information already on this forum than anyone can put onto a single thread. :D
    If you're interested in getting into these then you're probably going to read half the posts from this year anyway! :p

    It's a 66. But it is slim and looks like it fits the bike. :cool:
    There's a newish 70 kit with more power if you don't mind a wide-as-a-four-stroke screaming high RPM engine without parts availability. :rolleyes:
    I too am planning a walbro style (and reed). I don't really "get" float carbs on bikes. The walbro style is supposed to be easy to adjust outdoors and won't flood if laid down. :D
    The power depends how you rebuild it and run it. No mods and overly oil rich as per the instructions = 2hp, I guess. Loads of mods but even lower RPM = probably the same hp but quieter, I hope. o_O
    The carb, reed and head cost a few $ but most of the mods are free! :) I'm spending a fortune on bicycle parts, though. :oops:
    Recent posts list loads of fun, free / cheap mods that improve reliability, and efficiency (power without raising the top RPM). :)
    The engine is replaceable. You can even raise the power through RPM if you want to, at worst it's only going to kill the engine quickly, not the really expensive parts. ;)
    Jaguar has a site with loads of info on easy methods of balancing and porting. We discussed how to do balancing without even splitting the case, for those who have limited tools and skills (drill radially!). :D

    It is definitely worth it. :p
    Frankfort MB's likes this.
  3. skyash

    skyash Active Member

    By the time you spend all your money on it you should have got a real motor off a dirt bike and put it on a pushbike cost more to start with but will never do you wrong twice the take off and top speed 50cc vesper has 4 gears
  4. panmines

    panmines Member

    If you buy from a reputable quality vendor who builds these engines themselves, you shouldn't have too many issues with reliability. Half of the problems come from being massed produced in Chinese factories and the other half comes from bad engineering design. One thing to look for is the wording "machine balanced" crank shaft. I admit I have bought only one kit from one vendor, but it has been running for over a year and I have had no issues with it. I bought the F80 Kit from ThatsDax.com. I hear that some people are able to increase a 66cc to 6 hp with modding, but I can't say if they are reliable. I think the best way to maximize the life and reliability of these engines is to avoid over revving them (above 4800 RPM).
  5. skyash

    skyash Active Member

    Still the performance is weak compared to other motors in the same category. All the mods and time wasted when a better motor will do out the box
  6. Frankfort MB's

    Frankfort MB's Well-Known Member

    If you don't revv your engine above 4800 RPMs your not using ANY power
    These are two strokes. Powerband is up high up there, probably around 6-7k

    At least that's where my engines power is at:)
  7. Jonj57

    Jonj57 Member

    would that be the "bullet train"? I haven't heard that it's 70cc, if so fuuuuuudge ya I want it. Electric start, wet clutch, AND higher power? Sounds like my jam! Wonder if itll work with a sbp jackshaft?
  8. FurryOnTheInside

    FurryOnTheInside Active Member

    I think they are calling it that now. Last I heard it was pre-order only, they don't/didn't have them yet. There's absolutely no spares back up. They have not been long term tested. We don't know the bugs and fixes. There's no upgrade parts. It is as wide as a 4 stroke so you need the freaky bent cranks. High power with only 3 more cc means that it must be a screamer. So about as antisocial as a petrol scooter I guess, a cop magnet and not a good thing for MB public relations either. Definitely not stealth. It does not mount to the SBP shift kit.