Ready to Rumble....Blue Collar VS Dax!

Discussion in '2-Stroke Engines' started by andyinchville1, Aug 28, 2008.

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  1. Hi All,

    Just wanted to do an informal comparison between the Dax 70's that I have normally gotten and Blue Collars bike engine kit (I got the lower priced of the two versions he sells....I didn't want to wait until he got a new batch of his "better" engine kits (only $10 more than his lower priced kits) because I had somebody that wanted to buy a bike from me "right now"....So....I had to make one ASAP and get it shipped out....

    In all fairness, the engine kits I got from Dax are from awhile back so things may have changed since then...

    As far as delivery speed, other than Blue not having the more expensive kit in stock (which I wanted BUT when things sell well that's good huh?), Blue wins....

    In opening the boxes I gave the edge in factory packing to Blue Collar.....Inside the boxes, many of the pieces were separately boxed inside as well.....some even bubble wrapped Dax's kits ship to me well also just not boxed inside a biggie either way so long as stuff isn't broken when you get it right?....Just my first impression....

    After opening the pieces in Blue Collars kit, I noticed the carb already had the throttle cable installed.....nice....No fighting to have to install the throttle cable....Dax's kits required assembly of the carb / throttle cable but that may be good force one to learn how to do things (such as if you have to adjust the needle up and down with the eclip)...On the other hand hard to argue with convenience.....

    Instructions - Blue Collar By Far!!

    Gas tanks, CDI - Same either way

    Sprockets....Dax gets the nod here since his kit runs with the HD 9 hole mounts (8MM bolts) chromed and weighs less too (17.9 oz)....Blue Collar had a "raw" cast looking finish and weighed in at a somewhat massive 24.7 ounces... Both sprockets have the same tooth count.... Of course had I gotten the Upgraded kit from Blue Collar I would have gotten chrome too....I don't know if Blue's upgraded kit has 6 MM bolts or 8 MM bolts either case you won't be breaking the bolts and will probably want to upgrade sprockets in either case so this category may ultimately be a moot point.....

    Chains - about the same

    Mufflers - same but Dax's has the "round" bottom where the exhaust opening ends and Blue has flat bottom at the exhaust opening...No tuned pipes here so had to say if one is better than another.

    Clutch Lever - Both had lockout pins for the to hold the clutch out but I have to give the nod to Dax for being just a little nicer here on the area where your fingers pull the clutch in....less "taper" so my fingers fit better on the Dax Clutch lever....Blue's lever did have an extra screw to hold "adjust" the clutch lever tho....

    Throttle / Kill switch - On my older Dax kits I got the separate red kill button and rubberized throttle twist grip.....Blue gets you a throttle assembly that looks nicer, has a built in kill switch, but has a plastic feeling grip area....Tough choice here...If Blue had a rubber grip it would be Blue all the way but since not, I prefer the rubber feel of Dax....Besides I choke my engine out ;-)

    Chain Guard - Same

    Hardware - Same

    Idler pulley - Same

    Spark Plugs - About the same....The Factory removed the "tip" on Blue's kit
    kit so you don't have to unscrew it yourself...Not a biggie....but one more thing you don't have to do

    NOW the meat of the matter....The engine itself.....

    A quick glance, shows the finish on Blue Collar's engine is shinier than Dax's flat cast look....Maybe the factory used clear finish?....Blue's is probably easier to wipe clean because it is "smoother" but will this hurt heat dissipation?....Maybe a little but not enough to matter probably....

    Dax's engine uses a longer clutch pull lever....that is a plus....leverage makes working the clutch a tad the nicer clutch lever mentioned earlier to boot...

    Dax has a chromed intake BUT more importantly it measures nearly 16 MM ID vs Blue's 13.5 MM ID....Hands down Dax Inhales better (I did NOT take the intake off tho to see the actual size of the cylinder port opening tho).

    Not readily seen in the pics BUT Blue's head gasket looks to me to be
    about 3 to 4 times the thickness of Dax's head gasket.....Can you say easy compression increase by simply thinning the gasket ?!?!?....Hmmmm....uncork the torque!...Of course I didn't measure compression so hard to say what the result of thinning the gasket would be....(instructions say stock compression is 6 to 1).

    Cylinder - Dax has the top three fins that are a little larger than the others....Blue's cylinder doesn't ....Although the additional sq. inches of cooling fins may be nominal it theoretically can give a little better cooling due to additional surface area....Not a lot maybe but possible that every little bit counts....But then again it is probably so nominally different....

    Exhaust port - Blue wins Hands down here....Huge area for the spend gases to exit...Much larger than Dax.....Nicer gasket too BUT the gasket is NOT perfectly matched to the port opening and since it is metal covered it will have to ultimately be tossed if one is to match the port to the opening of the gasket.....Of course ALL this is a moot with the stock exhaust since the flange on the exhaust is smaller than the exhaust port of the cylinder.....Can you say "Dremel time"....

    Front Mounts - The Front Mount on Blues engine will accommodate a larger frame tube than Dax's (Blue has a larger opening radius)....that can be a PLUS or MINUS...Plus in that it will already accommodate a big tube BUT if the down tube is small there will be a gap....You can always File a Dax to fit....Although a little more work is possibly involved Dax get's the nod here at least for the smaller down tube equipped bikes...

    Heads - Externally Blue gets the nod here for the larger reinforcing ribs on the "dome" by the spark plug (see pics)

    Beef of block - Looks about the same But I like the Dax here because of the
    extra metal around the clutch lever opening, and the extra metal where the bolt goes through to hold the engine halves together (under the exhaust port)....Probably not of any real significance but it is a detail.

    So what about performance?

    In all, it may be easier to hop up Blue's engine...Simple bolt on performance...
    Bolt on the better intake from Dax, use a thinner head gasket to up the compression (I think the Dax head gasket would work BUT I did not open the engine up to verify)....

    To Hop Up Dax's engine essentially the same way you would have to remove the cylinder head to open up the exhaust port with a dremel, and you would have to mill the head.....a little more labor intensive BUT at least it's free... just a little time.

    As far as inside the engine....I didn't open it up...

    As far as real world performance....I had to ship the completed bike to its new owner....since I had to ship it out as "new" I couldn't run gas through it to see how well it ran.....A tragedy I know....BUT I will order another engine from Blue Collar just to see his upgraded kit!!....The T shirt and stickers were nice too!

    In all, The Dax 70's I run have been great....I'll look forward to getting Blue Collar's other engine and doing actual motorbiking with it just to she how it does in comparison.....

    Hope this helps....


    Attached Files:

    Last edited by a moderator: Aug 28, 2008

  2. Your Bratz Model Rules!
  3. arceeguy

    arceeguy Active Member

    Great information, thanks!
    I just got two kits, one from BoyGoFast and one from Powerkingshop - both on eBay. I plan on snapping a few pictures and doing a comparison much like yours. I will be disassembling the engines and taking some internal measurements to help with parts compatibility. (like piston diameter, wrist pin size, etc)
  4. Hi,
    Arceeguy....sounds good....If we review and disect enough engines we'll have a really good data base...I like the idea of trying to see which parts are interchangeable and
    which are not.....I wanted to tear into the engines but really couldn't this time around....Maybe the next one!....I'll be looking forward to your report.


  5. arceeguy

    arceeguy Active Member

    Right now, I've got pictures of the kits and how they are packed, and how they looked on arrival. The biggest difference right now is that PKS has better packing than BGF, and the PKS engines are painted silver. The PKS carbs are not "NT" carbs and have a chrome air filter cover and not black plastic. The PKS air filter foam is inadequate, as it is thin and you can see holes through the foam cell structure. I plan on replacing it with some cut down foam filter material for a dirtbike. (and oiling it) Haven't unscrewed the cover off of the BGF air cleaner yet. Much, much more to come! I think this database of information will be very helpful as there seems to be subtle differences between engines although they all look the same on the first glance.
  6. kerf

    kerf Guest

    This info would be a welcome addition to our vendor review section.
  7. Demosthenese

    Demosthenese Guest

    You should grab one of their slantheaded engine to compare Andy. I just got the 49cc slanthead from bcb, and it seems substantialy different from my previous pks engine, as well as my friends 70cc dax. It also came with the longer clutch arm, different intake, etc. Would love to see a side by side comparison of 2the two different engine models. This is great though!
  8. LabDude661

    LabDude661 New Member

    I've been running my boygofast engine for a couple of weeks now. I've really impressed with the ruggedness. It's taken quite a lot of tinkering and held up alright. Unfortunatly the decision was made based on price. I have no idea how long this thing is going to keep me rolling. I have been having a terrible time with vibration so it might be an unbalanced engine. I rubber mounted the engine and that helped a little but I'm going to try the old bird shot in the handlebar ends and see if that clears some of it up. I hit about 27mph and the thing just about rattles my arms off.
  9. Im sorry as far as I was wrong in my comparison Ive had a little more time and here is what I came up with. My BGF 4300 + miles

    BoyGoFast compared to Dax and Blue Collar:

    Head and Jug same as Daxs
    Crank (case at least) same as Blue Collar
    Clutch arm as well
    Thick 44 th Cast pot metal sprocket like blue collars
    415 hd chain not standard 415
    Chain Guard - Same
    Hardware - Same
    Idler pulley - Same
    throttle assbly with built in yellow kill switch chrome ended grips halfway comphy
    2 litre tank
    aluminum intake like blue collar I drilled it out to 16mm left a collar thcknss for booster in/outlt
    BGF is definately a smoother to touch.. nice! coulda maybe been a better caster on duty for jug..?
    Inner works low tolerances smooth almost a honed smoothness w/out cross directional lines on boar
    69.7cc 4:1 in to output up gearing from crank to cntr...6:1 compession...75psi compression at 4k miles
    russian (metal) locking clutch lever
    bought a new cdi (both work), 4 chains, 2 magnetos (burnt 2 up from a water level in magneto compartment), 3 chain rollers (3rd is new and on), a carb (both work), 3 sets of tires, 4 sets of brakes, on my second araya style cageless bearings quick release rear wheel, 2 throttle cables, 3 clutch cables, changed motor mounts to american sae 1/4" x 20 tpi and 5/16" in front, ngk plug, 8 spokes(all at the same time tensioner spun around chainstay bar pop pop and so on), oh and welded washers on the back side of chain guard bolt holes. One base jug gasket andone exhaust and 2 intake gaskets.

    When I say 4300 miles over 3/4 of it is rough terrain. Oh watch your gap don't go over 24 thsnds and keep your air filter cleaned and oil it and then ring the oil out after cleaning it.
    Last edited by a moderator: Sep 1, 2008
  10. Hi Guys,

    Actually the best thing that can be done (but it is expensive) is if somebody (Or a forum for that matter)....Could buy 1 of each of the more common engines from each major supplier and do an in depth detailed analysis / test of each engine.

    It would be best to purchase the engines not asking for a discount of any sort or mention that it is for review purposes so that the engine is representative of the what the seller actually sells.....Of course it would take a fair amount of time BUT it would definitely be useful info....A Real Dyno would also be a plus to see how the various engines compare powerwise....

    Lastly, maybe a run til it dies dyno run would see which engine is the most durable....of course similar test parameters must be established for each engine.

    Just an idea.....Any takers? ;-)

  11. arceeguy

    arceeguy Active Member

    Man, that would be a great video - a motorized bike on the dyno at a motorcycle tuning shop!
  12. ozzyu812

    ozzyu812 Member

    Whose bcb??
  13. HoughMade

    HoughMade Guest

    Probably Blue Collar least that's my guess....based on the thread title.