My first impression of the Grubee SkyHawk GT5A

Discussion in '2-Stroke Engines' started by 45u, May 2, 2016.

  1. 45u

    45u Active Member

    I received my new genuine SkyHawk GT5A today.

    I will be taking the motor all apart and will update once I do but so far my first impressions are GOOD! Here are the things I like better over my eBay motor so far.

    Has all socket head (Allen) bolts, will fit frames up to 43mm on the front, casting look better, 8mm front engine mount studs, screw in bushing where the mag wires come out and all around better appearance (looks better)!
    Timbone likes this.

  2. Hello Moto!

    Hello Moto! Active Member

    I can't wait to get one for my frame. Thing is the engine will probably be the last thing I buy for my project. Next thing on my list is a good set of wheels. I've been contradicting myself on what I'm gonna get but I have a little time to make up my mind.
  3. 45u

    45u Active Member

    Only reason I got mine all ready as I will be taking it apart and doing things to the inside.
  4. Steve Best

    Steve Best Active Member

    I think modifying something from the beginning is a big mistake.

    Establish a baseline with a completely stock machine, set-up properly as the designer envisioned.
    Try your mods one by one, seeing what works and what doesn't.
    These engines lend themselves very well to this type of experimentation.

    Stock, my Grubee GT5A had no problem reaching 50 kph and was quite quiet.
    With a $20 muffler it is even quieter.
    It now climbs hills better and reaches just under 60kph with no money spent, just some sanding and filing.

    By trying them one at a time I did learn some of the mods suggested on these pages do not work.

    I have a new head, pipe, CDI and other parts ready to go, but honestly, I am having a lot of fun on mine as it is!

  5. 45u

    45u Active Member

    Yes I have been enjoying my first build which is stock other then carburetor. Been modifying motors for 45 plus years. To old to change now.
  6. 45u

    45u Active Member

  7. FurryOnTheInside

    FurryOnTheInside Active Member

    I wish we could get those over here, all I could find was the fleaBay covered in thick black paint horrible ones. Cost too much to ship a gt5a over though. :/
    Rob H likes this.
  8. Big G

    Big G New Member

    I agree, go stock first and then experiment away.
  9. 45u

    45u Active Member

    As I said before I already have a bike with a stock motor. Defeats the purpose to have two stock motors bikes and is why I am building the second one as my hot rod. Been building performance motors for 45 plus years much of the time as a living. Is that your motor in your aviator? Sure is running rich looking how blue the pipe is.
    Last edited: May 9, 2016
  10. 45u

    45u Active Member

    I have started taking the motor a part and finding some things that I found on my cheap eBay motor. Much of the hardware is not tight and I am sure glade I am taking it apart. The lock screw for the clutch flower nut was not even finger tight. Just hope the Gurbee does not have all the grit and trash in it like the eBay motor did before I took it apart and cleaned it out. Will post more I get into it more. Yes at this point I feel it is a better motor then my eBay. Today working on my running motor bike.
  11. HeadSmess

    HeadSmess Well-Known Member

    better to use a stock engine and modify it bit by bit than expect to know how to modify everything in one big hit and end up with a large paperweight...

    at least if you do it step by step you know which mod made it a paperweight...
  12. Greg58

    Greg58 Member

    I take all new engines down to check things out, I like to clean up the ports and match them before I ever run it. If the piston doesn't clear the intake port at tdc I notch it also. I haven't found a lot of debris just casting flaws that should have been remove after casting.
  13. 45u

    45u Active Member

    Yes I take all my China motors apart before I ever turn them over. My first build was a eBay motor and it had all sorts of trash in it. I do believe that is why the recommend for break in they want you to run it with so much oil in hopes of flushing all the trash in the motor out. Mine had so much trash in it the rod bearing would not roll over with out getting stuck. Once I flushed and blow it out then oiled it then the rod bearing was fine.
  14. 45u

    45u Active Member

    One thing is for sure they are packed very well not like the others. I sent one eBay motor back as it was packed so poor there was a lot of damage to it. With the SkyHawk it is packed in Styrofoam. Only thing I wish they would have done is put the motor in a plastic bay as there was a lot of Styrofoam in the ports of the motor. Not a big deal since I will be taking it apart before I ever turn the motor over.
  15. KCvale

    KCvale Motorized Bicycle Vendor

    Yes, BirdDog Distrusting is great and an authorized Skyhawk buyer.
    Skyhawks are made in the Yang Dong engine factory in China, and their quality control is under the guidance of Don Grube's quality standards, hence why outfits like gasbike that have faked the quality name so long they can't even buy them.

    Damn fine engines out of the box with no crap inside and I agree with the 'don't break the case open first' crowd on these engines.
    E-bay, Woodpecker, Happy Times? I wouldn't buy them in the first place, not when there is a great engine without the fuss alternative, and have for years.
  16. Rob H

    Rob H Member

    That's what I did
  17. Rob H

    Rob H Member

    That's what I did for about six months
  18. Rob H

    Rob H Member

    I've said it in other posts try something out get it working right then move on to another mod another thing I do is always have an extra freewheel on hand clutch parts coil and cdi sprockets and so on I think you need to work up to going fast and going fast correctly is expensive
  19. 45u

    45u Active Member

    This is why my first build was stock this motor kit is for my second build! I have been doing performance work on engines for over 45 years most of the time as a living. I have built engines that have cost over 10K so I have no fear on this little engine. So why would I hold back? I would understand if I was nob like many here but I am far from that. I am not 61 and been working on engines since I was about 10.
  20. 45u

    45u Active Member

    I always take all my China motors apart before I ever turn them over as I have found WAY TOO MUCH dirt, shavings and trash it them. This sure is not going to help the engine so I make sure they are dead right before I ever turn them over. Since they did not put my SkyHawk motor in plastic bag before putting in the Styrofoam and it has all sorts of Styrofoam in the ports and not telling where why would I not take it apart to at least clean it out????????????