Boy go fast/engine

Skyliner70cc

Active Member
Joined
Nov 17, 2007
Messages
1,347
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:


Joined
Jan 22, 2008
Messages
195
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.
 

Skyliner70cc

Active Member
Joined
Nov 17, 2007
Messages
1,347
Sheik,
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.
 
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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.
 
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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 :)
 
Joined
Jan 22, 2008
Messages
195
Sheik,
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.
I'm miles away from my bike, but when I get a chance I'll get you the requested information.
 
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gone_fishin

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

me said:
please go search and/or discuss it in the frame-mount area.
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 :)
 

Skyliner70cc

Active Member
Joined
Nov 17, 2007
Messages
1,347
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
 
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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)
 
S

Simonator

Guest
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
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?
 
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