A warning to those looking to mod their motorized bicycles:

Most, if not all, of the hacks and mods featured on this site were made by individual hobbyists. If you are new to working with 2-stroke bicycle engines, please by aware that there's a possibility that a mod featured on this site could seriously damage your engine. Please don't try any mod from this or any other site unless you fully understand what you are doing. The owner of this blog will not be held responsible for both material and bodily damage caused by performing a modification featured on this blog. Also remember that opening up your engine may void your warranty!

Wednesday, June 27, 2012

Intake neck extension for power increase

This is another mod from dragonfly75.com.  It's not quite explained how exactly it works, but it's supposed to take advantage of pressure resonance from the engine to add about 15% more power if your bike is slow.  Interesting idea!


  1. Just went through your link. I found your post very informative, very useful to everyone to get interesting information about motorized bicycles.

  2. I think this isn't so much a speed hack as a low-speed torque hack. It gives better power climbing hills, and at other times when you need more torque at low speed.

  3. Fuel injection system is a jet per cylinder. Keep in mind that the fumes are what ignition not the liquid so this added extension area is where the air to fuel mix better. Older race cars had high rise intakes much the same concept, then comes blowers or just having the air intake facing so the faster you went the harder the air is pushing into the breather gave an increase of house power. Just now with my last comment made me realize that all these carbs their facing the wrong way. Fact that may cause a vacum effect with the way its facing now at high speeds.I am going to test my theory but after I've speed tested so I have a compare sent to share. I cant think of an easier mode to do and undo without damaging anything then this? Dirt/dust would be our enemy on this. This is my first conversion project of this kind and with anything research the unknown be safe then be sorry.....

  4. I am thankful for this blog to gave me much knowledge regarding my area of work. I also want to make some addition on this platform which must be in knowledge of people who really in need. Thanks.

  5. Your site is a real treasure trove! This tip is so useful, as my carburettor is constantly getting in my way and now I can shove it to the side just that little bit!