Problem With New Grubee Skyhawk 66cc Go-Sick'em Motor

Discussion in '2-Stroke Engines' started by Irish John, Mar 28, 2011.

  1. Irish John

    Irish John Guest

    Systemic Problem With New Grubee Skyhawk 66cc Go-Sick'em Motor

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    PICT0120a.jpg The specs for the new SkyHawk 66cc Go-Sick'em motors claim all sorts of "improvements" many of which are tosh but I now know that this motor has a serious systemic problem caused by the new design. Out of four new motors 2 have developed crank seal failure in the first 150 kms during the running in period and a third is showing signs of it after 300 kms. The Grubee specs claim "new improved oil seals" but the seals are the same as the old ones and the problem is cause by the increased compression of the new head design and the angled spark plug. The seals just can't cope.
    The "new improved sports carby" is also not as good as the older versions and my experience from 4 motors is that they all have to be re-set so the c-clip goes on the bottom groove on the needle. This seems to be a must to stop them bogging at half throttle or on hills.
    The symptoms of a blown seal are loss of power under load so the motor just won't pull under load. If it's the left seal that blown you will find oil inside your magneto cover and may see it dripping out the front where the wires exit if you tilt the bike downwards at the front. If it is the left seal that has failed replacing it is a doddle but how long will the new one last? I glue two head gaskets together to help decrease the compression and prevent this systemic oil seal problem from reoccurring. Can't tell if it works yet.
    Replacing the right seal is not a doddle.
    The increased compression seems to make it much harder to start this motor and it takes longer before you can turn off the choke. They seem to like having the choke on which is abnormal.
    The clutch is so much harder to pull in on this new Grubee model and it doesn't get easier in time. I've ridden all four motors for 225 kms before handing them over because that is how I do things and I don't always trust my customers to break the motor in properly.
    By far the most annoying thing about the new SkyHawks is that the engine mounting studs are not only no longer the same spacing front and back but are completely different from previous models so you can't use those old spacers you have saved in a box. Mounting the previous model on a beach cruiser frame was a doddle because you just needed to slide one of the rear spacers provided onto the front to reach the goose-neck downtube on the cruiser. Now the only way you can mount the motor properly on a cruiser is to get a block of aluminium billet and to machine it and drill it to fit the unusual front holding studs (see attached pics).
    Pretty well all the "improvements" claimed in the Grubee specs for the new 66cc SkyHawk G0-ick'em motor are mostly tosh. Those of us who have been around long enough to know how Grubee operate won't be surprised that they have decided to make 'improvements' that suddenly create new problems where they didn't have problems before. Don Grube doesn't ride nor does he listen to people who do ride his kits. This is very similar to their "new improved" 4G gearbox that was vastly inferior to the model it replaced.
    A few days ago a customer brought his bike in for a service and it had the old SkyHawk 66cc engine - the one without the angled spark plug. Having just ridden 1000 kms on the new SkyHawks it was very evident that the older model was much smoother to run, easier to start, more responsive to the throttle with better pulling on hills and a much, much lighter clutch. That bike had only done 280 kms since new and had been sitting unused for over a year.
    I just wanted to post these findings because I do not think that the wild overblown, ambitious claims by Grubee should be allowed to go unchallenged. As for myself I will no longer use the Grubee motors and will be trying Rock Solid to see if they are any better.
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    Last edited by a moderator: Mar 28, 2011

  2. Apachekid

    Apachekid Member

    Thanks for the post Irish......real good information. and pictures. I always knew that new Gruebee carb was a POS. But now I know the real story about the new and improved G kits.......they sound like a real pain in the ***. Ill be going to any other kit but G. Last Gruebee kit I bought was 2009 straight head. Its still running, but Im thru with Gruebee, too. Cheers, Apache
     
  3. Irish John

    Irish John Guest

    Thanks Apache, overall they are now a pretty useless motor and that is only because of the changes they made to the kit. They totally wrecked a good product. That's what happens when they don't ride their own kits - they become arrogant fat-cats.
     
  4. Apachekid

    Apachekid Member

    Exactly.
     
  5. Pablo

    Pablo Motored Bikes Sponsor

    Who drilled through a perfectly good frame? I thought with all the front mount options out there, we put that well behind us.

    So this bottom end blow out, it's not just an isolated occurrence? Those are strong charges, I think that may be why the thread was closed.

    "Go-SICK 'em" WHERE did they come up with that name? Like it or not, people in China talk too. We know Grubbee follows us. Wouldn't have it any other way. Frankly we hope he gets the bugs out and sells tons of engines.
     
  6. lsoult

    lsoult Member

    I'm surprised it was removed. This would have been helpful to anyone trying to put one of these on thier bike.
     
  7. Irish John

    Irish John Guest

    They may well get the bugs out although I doubt they are at all bothered about whether the kits work well or work badly. The real point is that the previous version had none of these bugs. It was a much better motor and much easier to fit on a cruiser for reasons I illustrated very clearly. The higher compression does not improve performance in fact it diminishes performance slightly. The motors won't run properly with the choke off and the clutch lever is very hard to pull - the motors are very stiff and slow to rev. These facts have been reported all over the place. All of the problems I mentioned didn't exist on the older version Grubee kit. This is a repetition of what they did with their 4-stroke kits when they "improved' those. People who don't ride the kits shouldn't make 'improvements'.
    I mounted the motor with a bolt through the tube on those bikes because they are both alloy downtubes and not only are the tube diameters really big ut the tubes have a very thick wall. As long as the bolt hole is drilled in the right place and bracketed really well on both sides it is a totally fast fixing that allows absolutely no movement. The front clamps availabe won't fit those tubes - they are good for steel down tubes which are thinner diameter.
    The alloy Schwinn is a stronger frame than the steel Deluxe Seven. The holes in no way render the downtube weak - my Merida Kalahari MTB has had 4 engines and done about 18,000 kms without any signs of damage over six years. My first alloy Schwinn had a hole drilled to mount a ZBox 66cc HT motor before it was replaced with a Honda GXH 50 and has done 22,000 kms over three and a half years without any frame problem. The Avanti downtube is totally irregular section varying from triangular to circular to ovoid which makes it very hard to clamp a bracket to.
    If you drill a hole in a Micargi cruiser the tube will soon crack and break right across but that tubing is mild steel and is not even bicycle frame tubing. I posted a thread about that in Jan 2010.
    I think from the messages I receive that my observations on the new Grubee it are pretty close to what a few others have been finding.
     
  8. NightCruiser

    NightCruiser New Member

    Hello,
    I am wondering why you haven't gone to the Grubee home page and sent them an email about your problems? I did, and Don Grube contacted me back within a day! He wrote to me from China, answered all my questions and seems like a cool guy. He seemed upset to hear about complaining on forums instead of first complaining to him, the manufacturer, or your retailer?
    He was wanting proof of the oil seal failure, which I couldn't provide since you only had pictures of your mounting issues. He seemed willing to admit and correct any issues that may exist if they can be proven. Do you have any pictures of the engines with the oil seal failures? I have read others writing about high compression, and doubling head gaskets etc. If there is an issue with the compression then Don Grube should be contacted and it should be ironed out. If the double head gasket helps then maybe he would start providing a thicker gasket in the kit, or make a change in newer heads to reduce compression? Seems to be a better route to contact the manufacturer to get issues ironed out rather than going straight to a forum where there isn't anybody that can help you? I think it is unfair that you claim your issues are being "swept under the rug" if you haven't followed proper channels to report and deal with your issues, have you done that?
    I think your mounting issues may be a problem for you and a benefit for others, cause the change makes the engine harder to mount on some bikes and easier to mount on others. One reason for the change in motor mounts was to accommodate better exhaust routing, a change that was apparently requested by lots of builders. So what is making you angry might be making others happy?
    The evolution of a product can be a bumpy process, making some people happy and other not so happy with the changes that are made. If the manufacturer is not willing to listen to customers a product can go from good to bad very easily, that's for sure. Fortunately Don Grube is easy to get ahold of and willing to email an average joe like me a couple times to discuss his product, I get the feeling he cares and so I would expect that he would put any valid criticism to use and improve his product. Give it a try.....
     
    Last edited: May 25, 2011
  9. Irish John

    Irish John Guest

    Hi NightCruiser, what I am saying is that the previous Grubee kits were OK and the new ones are nowhere near as good for reasons I have stated. I acknowledge your point that the inability to fit the new engine onto a cruiser frame with swan neck downtube might be of benefit to those who are fitting them onto other bikes but I also have fitted the engines onto other bikes and I dispute the veracity of that suggestion. I have known Don Grube for a few years and I bought the old stock off his original dealer in Australia who sold me the stock he still had left when he got out of being a dealer. I have also written to Don on numerous occasions but I gave up after the problem with the 4stroke gearboxes (which was identical to the problems I have referred to with the 2stroke kits in that he replaced a functional product with an disfunctional one) and in regard to the problem that I pointed out to him that the original 4G gearbox was wrongly geared and that the ratio he had published on his website was wrong his response was that people don't need to go so fast on bikes anyway. If Don cared about his customers he would read this and the other Forum. With regards to the Australian importer I no longer deal with him because he failed to show any interest in maintaining supplies of the older gearboxes and parts despite the fact that he had hundreds of customers who had already bought those products and were going to be left high and dry with no spare bushings or 11T freewheel sprockets. To cap it all he told me what price to charge for his kits and then started selling them at below that price without telling me which explained why nobody was buying them from me. All in all Grubee haven't ever displayed any real concern for their customers - it is all about selling boxes of kits and the fiasco over the 4G gearbox really illustrated this well.
    To give Don credit for one thing - he did start supplying the older 4-stroke kits with a 48T sprocket instead of the 56T one after I and probably numerous others told him the 56T was way too large for most general purposes.
    In short, Grubee kits could be a lot better if Don actually paid people to trial them and report back to him because he isn't allowed to ride them in China where he lives. If he can't do that he could achieve basically the same by following these threads and that wouldn't cost him anything or bite into his bottom line!
    Believe me Night Cruiser, the previous Grubee 2stroke kit was head and shoulders better than the new one that I am writing about. It also runs sweeter and more freely. The high compression has been a failure and the stiff clutch is unneccessary. The sloping spark plug does not result in improved performance either.
     
    Last edited by a moderator: May 26, 2011
  10. NightCruiser

    NightCruiser New Member

    I have been in contact with Don about your issue, I think this retailer in Australia may be the one you should be mad at. It seems that your "OLDER" Go-Sick-em engine did have some problems, Grubee acknowledged them and wanted the kits returned to them in exchange for units that didnt have the problem. Apparently the Australian dealer decided he wanted to sell them rather than return them, so Grubee sent them free engines to cover 10% of their order, they were supposed to make good to their customers with them. I get the feeling you never got a free engine from them for your trouble? Sounds like you should have. Those engines were sold to Australia only, so if they end up on the market anywhere else you should question that retailer.
    At any rate, the Go-Sick-Em engine was a lemon and was pulled by Grubee, you certainly don't want to buy any of them! They have had a few models since then, the newest being the Super Rat, which is similar in that is has the 203 bearings, but the Super Rat has a completely different bottom end crankcase. I am hoping the SuperRat is going to do better than then Go-Sick-em as far as reliability. Have you tried any of the Rats? (I know the CNS carb is less than ideal, but we have the EPA to thank for that)......
     
  11. Irish John

    Irish John Guest

    Thanks Night Cruiser that info really explains a lot and reinforces my opinions about the ethical practices of George Bushara the Grubee importer. He offered an oil seal so the problem could be fixed. I made my own thicker gaskets. The last exchange I had with George was in May 2010 when I questioned his professionalism relating to what I said above and he seemed to think that he was very professional because he makes much more money than I do.
    He sells kits in boxes and I sell finished bikes custom built to order - I think "bespoke" is the buzz word currently in fashion for anything made to order. My customers have to be satisfied so I'm left to cover the cost of a dud engine as well as the labour involved. What you said was most interesting and it's good to know that I can still spot a flake at thousand paces despite my advancing years.
    Most grateful to you for passing on what Don told you. Sadly I am not surprised to learn what George chose to do with the dud kits.
     
  12. Jumpa

    Jumpa New Member

    Epa to thank for that

    After reading that last part i had to laugh my backside off After seeing what the GE plant in Lynn MA. did the the environment at that plant I cant even see why the EPA WOULD even bother with these bikes. About 15 years ago I was at this particular GE plant with they openly run jet plane motors out side all over the place it is like a small city with in a city there are no cameras allowed no matter what and i can see why we had to dig a trench to pipe in a special kind of gas as well as run an exhaust system into the ground well when the excavator started digging the trench what looked like pure motor oil seeped into out trench right out of the ground mixed in with the aquifer right next to the ocean it was the most contaminated place I've seen on earth the water table wasn't even 6 ' down and it wasn't showing any signs of stopping AS IT SEEPED INTO OUR TRENCH.
     
  13. Fabian

    Fabian Well-Known Member

    So let me get this straight. You are making the claim that a higher compression ration above the piston is causing the crankshaft seals to blow out, which seems like a ridiculous statement considering that the piston and piston rings block the path to the crankcase when above the cylinder ports.

    Since when does an angled spark plug location have anything to do with the altering of crank case pressure?


    Also, let me get this straight: you drilled through the frame tube, weakening this critical area and placing stress risers where you don't want them to be.

    Seems odd that you are handing out advise based on what i have read and seen, not to mention the problem solving methods you have used.
     
  14. RATRODER

    RATRODER New Member

    There only two causes for crankcase seal blowout ,1 transfer ports open before exhaust port,2 down stroke displacement is grater than crankcase displacement.
    Both are common with poor design and manufacturing.
     
  15. 577-Jersey

    577-Jersey New Member

    good info here..lol
     
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