So my motor is broke again...

[DuctTapedGoat]

And know I went to unscrew this screws which connects left and right side of the motor and it is so hard I grabbed biggest screwdriver I have and I only managed to unscrew one and I tried other one but without succes and if I keep going like this I will damage them. Could someone give me some advice or some way that I can unscrew them. Btw I soaked them in wd-40.

You removed it too soon, but if you have it apart on the drive sprocket side put a socket over the nut that holds it on (more often than not the sparkplug tool that came with the kit will fit this, put a screwdriver through the holes to get leverage) and turn it to the right (not unscrewing it just yet) and watch what happens on the other side in the clutch area.

If neither gear turns then the large gear woodruff key went, if both spin but not the piston then it's the small gear key (most often offender.)

The gear is removed with the puller tool, key replaced.

It's recommended a very thin-walled washer is used to fill the gap that the locking ring doesn't always fill. The only person I know who has these is bicycle_motor_works on ebay, it's a small thin washer made of copper, and fits around the end of the crankshaft arm but inside the gear smaller than the diameter of the threads inside that lip. This way the gear is firmly pressed onto the driveshaft rather than being only almost tight when the head of the bolt bottoms out on the end of the shaft, premature of the correct press fit. (that's what she said)

I made one in an emergency situation (it was that or walk 4 miles or even worse take the bus) once, I used a multitool to cut an old keyring I had on my swash of keys into an equally small ring that fit perfect in that spot. Alas the damage was too much, and my crankshaft end had already been worn down to a mear couple millimeters too small...
Well anyway if I had some soda cans I could have made a really janky cap to fill in the difference, now that I have copper sheeting on the bike as just a large curved copper fender I can simply sacrifice a piece of that rather easily and actually "make do."

Anyway it's a problem that can be solved before it began. Probably why that specific gear has had so many problems with the woodruff key. If you just aren't aware that that gear isn't perfectly down tight from factory then it can end up being looser than normal, not good.

Then there's the too long bolt in the too small hole situation.. The end of the bolt bottoms out in the bottom of the threads but is too long for the head to actually press down.

If you replace the bolt or want to improve it then make it shorter than the hole is deep, and put a small washer in that area, I could even assume a piece of heavy gauge solid copper wire trimmed to fit in that small circle would work. Either way filling the gap and then torquing it down will lead to better results keeping the gear firmly in place while not adding any extra particular burden to maintain the motor.

Directional and resistive force at low speeds is what causes the bolt on mine to back off. It always happens when I'm loping the block.

 

[JunkyardDog]

You deserve what you got. Illegal pipe, riding 30-40 mph. Cheap Chinese engine. Why is it all the complaints seem to come from those with cheap Chinese engines that ride their bikes way too fast? My Honda GX35 on a Staton friction drive setup has been running reliably for years at a top speed of 18-20 mph (the legal limit)

 

[HumanPerson]

lol

 

[Baconator101]

You deserve what you got. Illegal pipe, riding 30-40 mph. Cheap Chinese engine. Why is it all the complaints seem to come from those with cheap Chinese engines that ride their bikes way too fast? My Honda GX35 on a Staton friction drive setup has been running reliably for years at a top speed of 18-20 mph (the legal limit)

Because the Chinese 2 stroke is the honda civic of bicycle motors, minus reliability consistency.

 

[Frankenstein]

You deserve what you got. Illegal pipe, riding 30-40 mph. Cheap Chinese engine. Why is it all the complaints seem to come from those with cheap Chinese engines that ride their bikes way too fast? My Honda GX35 on a Staton friction drive setup has been running reliably for years at a top speed of 18-20 mph (the legal limit)

Because the Chinese 2 stroke is the honda civic of bicycle motors, minus reliability consistency.

Not to mention 98% of the users are doing the cheap Chinese deal while practically only 1% are doing friction drives. You think the math would be simple, but here it goes, 98% of the complaints should be cheap Chinese motor related, now get out of general questions and move back to the friction drive sub-forum.

 

[gary55]

You deserve what you got. Illegal pipe, riding 30-40 mph. Cheap Chinese engine. Why is it all the complaints seem to come from those with cheap Chinese engines that ride their bikes way too fast? My Honda GX35 on a Staton friction drive setup has been running reliably for years at a top speed of 18-20 mph (the legal limit)

Shoot us a pic. of that dynamic steed. If we don't know what to build how will we ever have a bike as good as yours.

 

[DuctTapedGoat]

Not to mention 98% of the users are doing the cheap Chinese deal while practically only 1% are doing friction drives. You think the math would be simple, but here it goes, 98% of the complaints should be cheap Chinese motor related, now get out of general questions and move back to the friction drive sub-forum.

In my experience, what fails is this:
Motor Mounts/(Motor)
Rear Sprocket/(Wheel)
Chain/(Tensioner)
Stator/(Mag Coil)
Keys/(Small Cog)
Rings&Bearing/(Piston)
Head&H.Gasket/(Head)

By upgrading these things to after market parts, I've had pretty solid reliability with an affordable Kit engine.
It is the CRX of Bicycles.

 

[Street Ryderz]

In my experience, what fails is this:
Motor Mounts/(Motor)
Rear Sprocket/(Wheel)
Chain/(Tensioner)
Stator/(Mag Coil)
Keys/(Small Cog)
Rings&Bearing/(Piston)
Head&H.Gasket/(Head)

By upgrading these things to after market parts, I've had pretty solid reliability with an affordable Kit engine.
It is the CRX of Bicycles.

Talkin s**t again show me where you got aftermarket stator,mag,keys,rings, or head gasket thats actualy sold by the normal vendors!

 

[Carlos motors]

So at the end I need new clutch shaft and it cost few bucks (2 or 3$) from one vendor from china and shipping from china to europe for that piece which weigh max 300g is 27$..

 

[Carlos motors]

You deserve what you got. Illegal pipe, riding 30-40 mph. Cheap Chinese engine. Why is it all the complaints seem to come from those with cheap Chinese engines that ride their bikes way too fast? My Honda GX35 on a Staton friction drive setup has been running reliably for years at a top speed of 18-20 mph (the legal limit)

Could you first explain me why I got illegal pipe??? It is called aftermarket upgrades and from the day I bought the motor I started tuning it and buying better parts. Also I think 30mph is normal speed and definetly not "way too fast". And why wouldn't I drive it as fast as it can? Having 70cc motor with better intake,better exhaust,better spark plug,better head (on quality felt cruiser alluminium bike) why would it drive 20mph when all these things were added for going faster and better???...