Boy go fast/engine

Discussion in 'Dealer Reviews' started by Skyliner70cc, Feb 10, 2008.

  1. Skyliner70cc

    Skyliner70cc Active Member

    Note: After posting this, I went online and noticed that this vendor now sells engines with the locking clutch lever, roller wrist pin bearing, and bearing wheel tensioner. If clutch and paint issues are improved then my review may no longer be applicable. Please submit your experience with these engines!

    I've had the opportunity to purchase two of his engines over the last 3 months.

    Here are my general observations:

    1. Quick shipping is a plus.
    2. First engine was not properly packed and the plastic throttle assembly was (crushed) damaged. Vendor replaced it reluctantly but said he normally requires buyers to file a claim with the shipping company. Shipping company would not have honored the claim if I had. The box was not damaged on the outside.
    3. Cheap older style clutch assembly. Yuk! These types NEVER work on amy of my bikes. They can't be depressed sufficiently to lock on my Skyliners or Searcher bikes.
    4. Both engines start easily and are VERY smooth. Much less vibration than my older Dax engines. My only comment regarding the engine is that the engine is very sensitive to the choke setting and requires some fiddling with the choke while starting to get it to fire up. I drilled out the hole on the choke plate and opened up the airflow going into the engine. This solved the problem and engine now starts easily on full choke.

    5. Clutch: BAD. Unlike Dax engines, the clutch cannot be adjusted properly. To this day, I cannot find an appropriate setting on the cable that allows me to have the clutch engage completely when released and NOT spin the wheel when it is locked into place. I have never had this issue with Dax or Kings motorbike engines. Also, the clutch setting seems to be tempermental and dependent on temperature. On colder days, releasing the clutch lever does not allow 100% positive engagement and clutch slips when starting. On warmer days the opposite is true and locking clutch does not completely allow disengagement. This is a deal breaker for me and the 75 bucks I saved in buying these engines is not worth it in my opinion.

    6. Power: First engine power came on quickly with my normal break in procedure and was pulling 25 up hill on a 50 tooth sprocket. Second engine can only muster 17 mph. I'll let you know if things change.

    7. Paint: Probably the worst paint quality I have seen in the almost 50 Happy time kits I've purchased over the past several years. If you value a decent paint job on your tank and chain guard, look elsewhere.

    Overall comments: Value is offset by the clutch issue, need to buy locking clutch and a true roller bearing chain tensioner and lousy paint job. You get what you pay for.
    Last edited: Feb 10, 2008

  2. I bought 2 of these engines. He sold them to us for 300 shipped for both.

    1. Quick shipping as well. Ordered monday and they were here by friday.

    2. Both engines came intact, nothing damaged. The packing wasn't the best but in my years on online buying I've seen much worse.

    3. The clutch was a metal job with a big springloaded lock button. It works well enough, I have no complaints really.

    4. The first engine started real easy. We couldn't get it to turn over the second day, but we found out that it was due to the fact that the white wire accidentally grounded itself against the frame, creating a kill switch.

    5. The clutch on ours was fine. It took us about 3 times to get the clutch adjustment to our liking, but now that we do have it set up, it's been working great. Sorry to hear about your negative experiences, Skyliner.

    6. Power is fine on the first one. It zips around pretty good, I have no real speedometer so I can't give you an incredibly accurate reading, but it's plenty sufficient for me.

    7. The paint on ours was pretty mediocre. The tank had a bubble or two in the paint and the guard was pretty smooth on the outside but had tooling marks on the inside.

    In conclusion, the kits worked out fine for me, and the price was right. I have no complaints.
  3. Skyliner70cc

    Skyliner70cc Active Member

    Start your engine, let it warm up and then disengage the clutch and lock it. Lift your rear tire off of the ground and let me know if it spins and if so, how fast. None of the many other engines I have isntalled had ANY residual clutch engagement with lever locked and NO rear wheel spin when it was lifted. My main concern is that the tiny bit of engagement will eventually glaze my clutch friction material and require replacement.
  4. Alaskavan

    Alaskavan Guest

    It's good to see this kind of product review happening on MBc. So many Newbs ask about engines as their first question. Reviews like this will provide them the answers. Also, hopefully, reviews will get more vendors to pay attention to quality. Cool.
  5. gone_fishin

    gone_fishin Guest

    there is an adjustment on the pressure plate also, i think this is what you guys are talking about, but please go search and/or discuss it in the frame-mount area.

    it is good to note here tho that a boygofast engine may require this prep work :)

    i agree with van...the review feature is really putting us on the map, and "what's the best" will be obvious someday, thru consumer-written reviews...thanks for starting this one :)
  6. I'm miles away from my bike, but when I get a chance I'll get you the requested information.
  7. gone_fishin

    gone_fishin Guest

    just a reminder...this started as a consumer review & we can't let it become a clutch-repair topic.

    if there's nothing on the subject already, then please start a topic about it...this is how the "tech manual" grows...with everyone's help :)
  8. Skyliner70cc

    Skyliner70cc Active Member

    Well, the engine seized after 70 miles on it. The roller bearing failed causing roller bearing pins to jam between the piston and cylinder. in defense of the engine, I was doing 32 mph on a 50 tooth sprocket. I believe I overrevved it. Regardless, never had this issue with any other manufacturer with their engines. No oil holes to lube the roller pin bearings were observed drilled at factory...hmmmmm
  9. eltatertoto

    eltatertoto Guest

    only thing that has gone wrong on either of my engines themselves is clutch issues on the 1st engine, the flower nut stripped out. other than that ive been good (knocks on wood)
  10. Simonator

    Simonator Guest

    32?! I hit 23 with the 50T sprocket, on 26" wheels, and it sounded like i was over reving the engine. Do you mean 23 mph?
  11. eltatertoto

    eltatertoto Guest

    simon that sounds about right. on my blue bike with 26 inchers, i dont take it above 25 cause itll do around 33-34, but it sounds like the thing is gonna blow up...
  12. Simonator

    Simonator Guest

    The highest I have hit with the 44T sprocket, and 26" wheels is 30 mph. Assuming my speedometer is accurate.
  13. hot70cc

    hot70cc Guest

    I weigh 170 and i get 34mph out of my 44tooth 70cc. I would definatly check the speedo accuracy.
  14. Rich

    Rich New Member

    how fast?

    i weigh 155 and have a kings "80cc" engine, on a 26 inch mountain bike. i was clocked at 42 mph by someone in a car.I have a 44 tooth sprocket. the engine was wound tight!
  15. Alaskavan

    Alaskavan Guest

    Skyliner, could you run the figures and tell us what RPM the engine was at just before it broke?
  16. stude13

    stude13 Active Member

    i bought one of those chinese engine kits and was so dissatisfied with the whole fit and finish and the overall quality of the metal used, that i only saved the peanut tank. i bought a subaru powered gebe kit and rode it for two years before i put the kit on a threewheeler for a kid with MS. gebe kits are bullet proof, kevlar belt and plastic drive ring. with the subaru i got 30mph and 200+mpg, quiet no smoke and no messing with a clutch made out of yak hair. ride on
  17. Skyliner70cc

    Skyliner70cc Active Member

    Speedo was accurate, I was going downhill. One of the few good things on this BGF engine is that it is VERY smooth, loves to rev, and has very little annoying vibration at higher speeds. Its also very quiet compared to other 2 stroke HT engines I've used.

    I'm keeping my speeds below 25mph from now on on this engine. When I put the new jug and piston in, I overtightened one of the stud bolts stripping the thread on the engine block. I planted the stud with JB weld and let it cure overnight which solved my problem.
    Last edited: Apr 26, 2008
  18. hot70cc

    hot70cc Guest

    keep an eye on the the stud, the JB weld may fool you and not hold up to the vibration.
  19. Skyliner70cc

    Skyliner70cc Active Member

    JB weld will hold up to the vibration. There was plenty of residual thread on the block for it to bite too.

    JB weld did a wonderful job holding up the vibration of a CH-47D helicopter. I had a cracked turbine engine casing that was leaking oil. I had the option of being stuck in the middle of nowhere waiting 1 week for a multi-million dollar replacement to be flown out to me plus the hassle of installing and testing a repalcement engine is a pain in the you know what. Stop drilling the crack in the turbine's engine case coupled with JB weld fixed the problem. Yes, it was an unauthorized repair and would have got me fired as a maintence test pilot but it worked and saved us a lot of inconvenience and hassle. I never bothered replacing the engine either when I got back on homestation and flew that aircarft numerous times for 2 years thereafter. I don't mind ratting on myself, I've been a civilian for 5 years now ;-)

    A CH-47D vibrates slightly more than a happy time engine but thanks for your concern. JB weld, when properly used and cured before use works. I bet my life on it and have.
    Last edited: Apr 28, 2008
  20. sparky

    sparky Active Member

    That must be some heavy duty JB Weld... that stuff always breaks on me.