Good, two stroke motor kit.

Discussion in 'Motorized Bicycle General Discussion' started by Eric2.0, Feb 21, 2015.

  1. Davezilla

    Davezilla New Member

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    Agreed, but that's one less thing we gotta do when we get an engine and since we cant just walk in somewhere to inspect them ourselves its nice to know we're getting a good engine to start with, not to mention having the good hardware is another thing we don't have to do, my first engine came off ebay and the vibration was unreal, the crank was aweful, and it lasted a whopping 90 minutes of run time before I noticed a critical issue that would have destroyed the engine within a few more hours of run time so getting a pres inspected engine that runs smooth right out of the box at a decent price is a big plus for me.
    When I found the problem with that engine I bought a Dax bottom end for $69 and put my top end on it and the difference was night and day in the smoothness department, even at 10k rpm there's almost zero vibration. I'm totally happy with that setup.

    Now if we could walk into a shop and hand pick which engine we took home with us things might be different but since most of us only buy one or just a few of these off the Internet its good to know we're being sent a good engine either to install and ride or to start a good high performance build from.
     
  2. mapbike

    mapbike Active Member

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    Dave,
    Im purdy sure the bolt pattern for the jug is smaller on the 49cc engines and I think you would also need to bore out the case where the jug slides down into it inorder to get a 66cc jug to work.

    I have an old 6666cc engine that has a smaller stud ppattern, it may be the same as the 49cc engine since its also got the 6mm studs instead of the 8mm like most all of them have now.

    I know BGF still sells a replacement top end for the small pattern 6mm stud 66cc engine and he still has some lowers also, they have the Z-L rod and are 40mm stroke.

    Not sure if any of the 66cc jugs with 6mm studs could be made to work on the 49cc lower but it may be possible..

    also since I dont have a 49cc engine, I dont know if all of them have the same stud spacing, Im just assuming that they do.

    I know Greg58 runs the 49cc engines so maybe he can ring in here and shed some light on it.
     
  3. mapbike

    mapbike Active Member

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    when I shared that link for those engines that song-top sells, I was thinking seriously about ordering one, looking back that would probably have been a better route to go rather than ordering the claimed 40mm stroke engine kit I did out of Hong Kong and actually getting a Half Breed engine that doesnt have nearly as good of balance as any of my dax engines or the latest GT5 I built up.

    If I order another kit off of ebay this year it will be one of those from song-top since I want to see for myself what the run characteristics of those engines are.

    Bottom line on these engine as far as equity is concerned is that truly most are a crap shoot just as they have always been, but I will also say that the majority of these newer kits are coming with better cranks in them, it seems the kits with the horribly balanced engines that will darn near shake the wheels off a bike are getting far and few between, I know there are still some of the old kits out there becAuse I've seen pics on ebay that shows signs of the engine being the older model.

    Yes the engines and the kits cost more from thatsdax, but he doesnt sell the old junk engines and he inspects things for potential problems ahead of sending them out and although the engines aren't made in the USA they do have inspection and some assembly done here to help insure the customer get a good engine right out of the box, tell me anyone else in this business that does that other than the engine builder that are getting $400-$700 for a custom high performance built engine?

    None that Im aware of and I've bought 6 engines from Duane so far and no lemons out of the box, I do have one that has developed accesive end play in the crank, but since it was the engine I ran a little hot and did my first 50+mph running with I may be the blame for whats wrong with that one which will be easily fixed and going again when I have the time.

    I say buy what you want and feel confident with, but for me I feel very co fident in the engines from thatsdax and Duane stands behind his product with good customer service and 9 times out of 10 when you call him he answers the phone and will chew the fat with you just about as long as you want, this is the kinda fella I like to do busy less with, there's a lot of value in knowing you can depend on a product and the fella your giving the hard earned money to in my opinion.
     
  4. Eric2.0

    Eric2.0 New Member

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    Thanks for this, I'm settled on a DAx motor, merely because I just want to have a chance at getting one of these to actually run and it seems the best chance is with Dax. Since he inspects and does some messing around with them to make sure they have a chance at life, lol.

    Nice bike BTW. I saw pics. I'm going up to Target to get mine in a few minutes. They have it for 29.00 clearance so it's a no brainer.
     
  5. boxcar

    boxcar New Member

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  6. mapbike

    mapbike Active Member

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    Thats great to know boxcar, I'm gonna try one of these before long myself, people do to understand that the limiting thing about thse particular engines is that the after market manic intakes and the offset Z shaped intakes wont work on these engines since the bolt spacing on these jugs on the intake side is 35mm instead of the 32mm and 40mm spacing that is more common in the past.

    But I will also add that since the intake on these is port matched to the cylinder all that is really needed for great flow is to bore the ID of the stock shorty intake a bit and it will be ever bit as good as the Manic type intake.

    If these engines have as good a balance as you say boxcar, these should be real winners with a little bit of port cleaning and possibly shaving the deck down just enough to get the piston perfectly level with the jug when torqued down, slap a Puch head or Fred head or whatever will give better compression and it should be a real good running engine with the good balanced lower if the main bearings stay put and dont do llike the one Dave has.

    No doubt i'm gonna have to give one of these a try.
     
  7. mapbike

    mapbike Active Member

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    I dont know how much experience you have with these engines for sure as far as getting the fuel mixture set right by changing jet size in carb, but honestly, if any of these little china girl engines are set up right and the Mag and CDI are sending fire to the plug, they will run.

    You said you could never get that Stinger engine to run for you, what do you mean by not run for you?

    Do you mean it wouldnt ever start up at all?

    Or do you mean it just wouldnt ever run good enough for you?

    The reason I'm asking you this is because it doesn't matter who the engine is from or how well it's put together if it isn't set up right on the bike, it isn't gonna run.

    I'm just trying to get an idea of what you have done and exactly what your last experience details are so maybe we can help you to make sure you have a better experience this time around, I know myself and several others here want to hear that you are zipping around having a great time on your bike once you get the new engine buckled up on it.

    If you can share pictures of your bike on here that will be good also, that way we can see what ya got and can possibly suggest way to resolve or prevent issues you could face with the new build.

    Best wishes and lets see if all of us together here can see to it that you have success this time.

    .wee.
     
  8. boxcar

    boxcar New Member

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    As soon as I manage to get The Huffy broke in . I will be finding out just how well they work with the Fred head , a good trim....Etc. Will be the "hot rod".
    I'll let you know.
    The Centrix has just clocked 700 miles.
    I'm going to leave that engine alone. As it is my base line bike.
    I did have the head off last night. Just for inspection...
    Clean and tight....
     
  9. mapbike

    mapbike Active Member

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    Sounds good, I'll enjoy knowing how well they do on the upper rpm end, they have to be smooth at top rpm's to make me happy since that is where I do most of my riding, long stretches of county roads here in my area with no shoulder and speed limits of 75mph for the traffic passing me makes me ride as hard and fast as I can on those roads with a good rear view mirror so I dont get plastered from behind by a cager, I did have a truck load of teenage boys through a big cup of ice in my face one day while I was clicking along at about 45mph, I think the anger I felt after that brought a new definition to road rage, I tried to find those boys, but I guess its a good thing I didn't... it would have gotten ugly...LOL

    If I didn't already have so many engines sitting in the shop now I'd go ahead and order one of those kits from song-top but I need to weed out a couple I already have before I take on another project since I already have more started than I can seem to get finished as it is.

    Yes keep us posted on how the song-top engine does overall and what the power and balance is like in the top rpm's.
     
  10. Slogger

    Slogger Member

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    My engine also came from Duane at Dax. Gen IV.
    Taking a look at it I saw it had no head gasket installed. Hm. Then I checked the deck height of the piston, looked at the mating surfaces between the cyl and head, they looked carefully machined.
    Put it on the bicycle and it has about 200 miles on it now. This engine has never so much as seeped fumes around the head or exhaust port, or the cylinder to case.
    Bone dry. nothing to wipe off.
    This was a new expeerience for me, I'd worked on a couple of these before and they all seemed to leak just a bit.
    It runs real smooth and starts right up. It's a very good little engine.
    I'd buy another one with no qualms at all.
     
  11. maniac57

    maniac57 Old, Fat, and still faster than you

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    No idea where this is, but the prices are right!!
    Notice the jug for under $10 on page three....
    http://cozy-mart.com/motorcycle-parts/motorized-bicycle?p=1
     
  12. mapbike

    mapbike Active Member

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    When I talked to Duane on the phone here a while back, he told me he was running his new GT5 platform engine with out a gasket and running the Puch/RT head on it with excellent results, if the surfaces of head and cylinder deck are true and the head nuts are torqued down evenly this setup is gona work just fine on a GT5 or half Breed engine since the piston lacks a few .001"s coming up the the ideal TDC.

    For mine I'm just shaving the jug deck until I get piston as far up in the hole as I want it and then use a gasket, but it seems that on these GT5 and half breed engines not using a head gasket is an improvement if you use a head other than the stock kit heads that are known for warping and sometime even giving issue when using a gasket.

    The Puch/RT head and several other aftermarket heads we have available these days should work good without a gasket as long as the deck is surfaced on fine sandpaper taped to a piece of glass to get a smooth flat deck so it will seal good.

    I'm also a fan of Dax, just hard to go wrong with dealing with him or the products he sells so I promote them.
     
  13. Slogger

    Slogger Member

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    If it seals up well without a gasket it's just one less thing to change dimensions or worry about. I was real surprised to see it without one.
    No probs at all. I don't know if the cylinder has a base gasket, I never took it apart. I will probably take it down to check the porting for flashover sometime when the weather warms up. I won't be dremeling anything else.
     
  14. mapbike

    mapbike Active Member

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    These parts come straight out of mainland China, yes the prices are right on, I have tried to order from them twice and for some reason my pay pal wont seem to go through so my order never gets made, not sure what the deal is.

    Maybe its just something i'm not entering right, I'm thinking it may be that my phone number has changed and I may not have updated that in my pay pal, that may be the issue because they ask for a phone number when you fill out the order form and that may be why mine didn't go through before, I guess while its on my mind I should look into that so in the future I might be able to place an order if I want.

    The shipping they offer if you will choose "China Post" is reasonable also.
     
  15. Davezilla

    Davezilla New Member

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    Thanks, gonna order 3 of them from there... 1 to fix that customer's bike (which I just looked at and it's a 66cc installed on the bike) and 2 more for me to keep as spares.

    Map... Yeah, I looked at the engine he had wrapped up in a box at the shop and there's too much work to make it worthwhile to convert a 49cc to a 66...
    The holes are a little closer in and the base is just the wrong size. If he wants that engine running again I'll have to do it up as a 49cc.
     
  16. mapbike

    mapbike Active Member

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    Dave let me know if you're able to get an order with them to go through, I decided to try to order a couple things again a few minutes ago and I couldn't get order to take this time either, checked all my pay pal info and its all up to date and correct so I dont know whats the problem.
     
  17. Eric2.0

    Eric2.0 New Member

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    Hmmm I might be using a 1961 Rollfast cruiser I remembered we have sitting in the back room. It's great shape and lots of room for a motor. Built in USA it says. I forgot I had that bike. I brought it up and wheels roll, frame looks good. Just gotta take the front basket off and flip the bars around for the board racer look. I might even put mountain bike handle bars on it.

    To me the cruisers look better with engines in them so I might just use it.

    A cranbrook I can get for 40 bucks too.

    Anyways I ordered the F80 kit GenIV from Dax. This will be a basic build, solid engine installation and safety considerations..... I just want to get riding one of these and see how I like it. Would be fun in the hot summer evenings riding to the store and what-not....get away from all the internet and Terrorist BS for an hour, lol.

    So yeah....it's a Dax engine and 1961 Rollfast.... It looks like this one..

    [​IMG]
     
  18. mapbike

    mapbike Active Member

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    That will make you a nice motorized bike and be a much stronger and more comfortable build than the Thruster Fixie frame.

    Take the hubs down and pack the bearing good with a quality tacky grease, make sure all the spoke are tight, put some thick thorn resistant tubes and good 26x1.95 tires on it and get that engine installed solid on that frame with NO RUBBER or anything else between engine saddles and frame, get wiring done properly with good sealed type connectors, use loctite or similar product on all fasteners studs, bolts and nuts, put a quality NGK B6HS spark plug in it, get clutch cable installed and dont use small diameter spring between clutch arm and clutch cable housing stop, etc....

    If you put this engine and parts on that bike the right way, you can enjoy a good running and riding bike from the get go without a lot of fuss and issues to work through and I know several of us on here will gladly point you in the right direction the best we can on every aspect of the build to help you get it right the first time.

    Enjoy


     
  19. Eric2.0

    Eric2.0 New Member

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    Thanks, Mapbike. You give great tips, appreciated.

    The first one I built was a Cranbrook with the Stinger 80 on it. I'm mechanical, but I could never ever get that thing to do anything....not even fire. I think all I got was a muffled PPvvvvffff for a few seconds, lol. I built the bike up good too...it looked great.

    I put it away and I think I traded the thing for something.

    Also that bike in Target wasn't a thruster....it looked like one, but much junk TBH....I could see pin holes in the welds....29.00
    is too much IMO.... Doesn't even seem safe to be a pedal bike.
     
  20. mapbike

    mapbike Active Member

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    Well I bet this time will be very different for you sir, and I know we will do whatever we can to help you get anything worked out that may become an issue, but I bet you get this done with flying colors and have next to no problems and this is my wish for you on this build.

    Well maybe those cheapo bikes are just thruster fixie knock offs or crap thrusters off the line that couldn't live up to the slightly better cheap bike standards and got relabeled and sold dirt stinking cheap to other big box stores.

    The welds on the Thruster Fixie I have look good, not like super perfect tig welds but there aren't any pin holes or noticeable bad welds, I looked this bike over really good before I would even pop on it for the $49 I gave for it.

    Sounds like you made a good decision staying away from that hunk of junk.

    The Rollfast will make you a great bike...
     

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