About ready to give up on MB's

[panmines]

Grade 8.8 replacement mount studs or Chinesium stock generic non-Grubee engine mount studs?

Most of these engines need to have the cranks balanced better.

These responses are hinting at a bigger issue. Where did you buy your kit; from a retailer or from someone who builds the engines them selves? I have bought only one engine two years ago from thatsdax.com (an engine builder) and never had a problem with the engine or its internals because it was built with higher quality parts. I have had a lot of other things break on me, but those were components not related to the engine (clutch lever, throttle, etc.). I think half of the quality problems with these engines come from their design (not easily fixable), and the other half from their assembly (easy to fix). You'll at least avoid the assembly issue and some of the design issue if you buy from a quality engine builder. The only down side is your going to pay more. IIRC, I heard someone say Dax sells just a 69cc engine for $150. This could be a good place to start if you still want stick with motor biking.

 

[kmarcetjr]

These responses are hinting at a bigger issue. Where did you buy your kit; from a retailer or from someone who builds the engines them selves? I have bought only one engine two years ago from thatsdax.com (an engine builder) and never had a problem with the engine or its internals because it was built with higher quality parts. I have had a lot of other things break on me, but those were components not related to the engine (clutch lever, throttle, etc.). I think half of the quality problems with these engines come from their design (not easily fixable), and the other half from their assembly (easy to fix). You'll at least avoid the assembly issue and some of the design issue if you buy from a quality engine builder. The only down side is your going to pay more. IIRC, I heard someone say Dax sells just a 69cc engine for $150. This could be a good place to start if you still want stick with motor biking.

I bought the kit from bicycle motor works.
Honestly I don't know what I'm going to do just yet, seems like I've invested the money, but don't want to keep sinking money into it every two weeks.
I am considering an electric kit, yes considerable more money, but seems like less to go wrong.

 

[Frankenstein]

Sounds like a result of engine vibration. Most of these engines need to have the cranks balanced better.

Shut up Carl. No just kidding he's right, they all vibrate pretty annoyingly at high rpm, and having a jackshaft helps since you can keep the rpm lower while getting good speeds and acceleration rates. If you go the extra mile you'll end up with a very fun and long lasting motor.

 

[panmines]

I bought the kit from bicycle motor works.
Honestly I don't know what I'm going to do just yet, seems like I've invested the money, but don't want to keep sinking money into it every two weeks.
I am considering an electric kit, yes considerable more money, but seems like less to go wrong.

Have you considered a four stroke? I haven't had any experience with them, but the consensus is they are 5x more reliable than a two stroke. Plus, if you bought a 4-stroke kit, you would already have a back up gas tank, throttle, and chain. And they are a lot more economical too. A complete 4-stroke kit from Kings Motor Bike is $350 while a 250w hub motor w/battery kit from Bikeberry is $600. Dollar for dollar, I think you would get more value out of a four-stroke. Before I even knew motorbiking existed, I went around shopping for a bike to put an electric hub motor on. One shop owner said electric motors were still in their infancy were expensive and unreliable. He advised me to look into motorbiking and I have never looked back at electric.

 

[kmarcetjr]

Have you considered a four stroke? I haven't had any experience with them, but the consensus is they are 5x more reliable than a two stroke. Plus, if you bought a 4-stroke kit, you would already have a back up gas tank, throttle, and chain. And they are a lot more economical too. A complete 4-stroke kit from Kings Motor Bike is $350 while a 250w hub motor w/battery kit from Bikeberry is $600. Dollar for dollar, I think you would get more value out of a four-stroke. Before I even knew motorbiking existed, I went around shopping for a bike to put an electric hub motor on. One shop owner said electric motors were still in their infancy were expensive and unreliable. He advised me to look into motorbiking and I have never looked back at electric.

No I haven't really considered 4 stoke, Aren't they a bit heavier and bigger in physical size, taller, wider and longer? Maybe I will have to check into them.
years ago I thought about putting a Bionix electric system on a bike, they were too expensive back then, about $1200 for a kit. I was looking on Amazon I found a kit for $180 and a battery for $230, much better than they were a few years ago.
If I don't do something with it I will have a cruiser bike I will never ride. My pedal bike is 10 times better than the cruiser.

So I just did a quick check on 4 strokes, Are they all "grubee"'s, or are some cheap imitations?

 

[gary55]

I like the ones from bicycle engines.com. Mainly because they have the clutch bell carried by bearings rather than a oilite bushing on the 4g belt drive with the taper shaft engine. I am pretty sure the 5/8" straight shaft, and all the others sold use the bushing. Somebody jump in here if I wrong on this.

 

[CrazyDan]

http://www.bicycle-engines.com/49cc-4G-T-Belt-Drive-Complete-Gas-Powered-Engine-Kit.html don't buy from gasbike or kingsmotorbike. Go with quality first and you'll have less heartache. The straight shaft uses the oilite bushing, tapered shaft uses bearings on the clutch bell shaft.

 

[gary55]

http://www.bicycle-engines.com/49cc-4G-T-Belt-Drive-Complete-Gas-Powered-Engine-Kit.html don't buy from gasbike or kingsmotorbike. Go with quality first and you'll have less heartache. The straight shaft uses the oilite bushing, tapered shaft uses bearings on the clutch bell shaft.

Hay Dan. A little off subject, but I got that staton clutch in. The engagement is much smoother. It has a little bit more noise and vibration than the stock. I am guessing it is because of diff. compound of pad, and the new pad needing to break in a bit to conform to the arc of the drum. What was your experience with it freshly installed?

 

[CrazyDan]

The same as you just described. As it wears in engagement should be much smoother.

 

[Randall]

I bought the kit from bicycle motor works.
Honestly I don't know what I'm going to do just yet, seems like I've invested the money, but don't want to keep sinking money into it every two weeks.
I am considering an electric kit, yes considerable more money, but seems like less to go wrong.

Uhhhh, wait a minute, this engine is from BMW? Those engines are suppose to have all upgraded bolts to 8.8 grade. I have one. Runs great. Something else is amiss here
Jaguar, they are balanced. Mine only has a very little mid range vibration, not enough to break bolts and I barely notice it. Maybe Matt missed something (no one's perfect). I would email him and let him know what happened. He is very helpful.