YD100 performance increase?

[Megaphone]

Still working on getting my jetting right but YD100 with 36tooth sprocket and expansion chamber pipe I'm only seeing 34MPH .. Would think I would be at 40mph ..

Speed carb with 70 jet and slide clip on one from leanest .. still 4 strokes at the top end .. and will try 69 this week ..

Looking for any other idea's

 

[lazar26]

I got about an 8mph increase from adding just the cheapo expansion chamber. Was going 30, now goes around 37-38mph on a flat. I too had to lean it out as far as it can, and add a hotter plug, although I have a 65 jet. Seems to work well without any 4 stroking.

 

[ImpulseRocket]

Still working on getting my jetting right but YD100 with 36tooth sprocket and expansion chamber pipe I'm only seeing 34MPH .. Would think I would be at 40mph ..

Speed carb with 70 jet and slide clip on one from leanest .. still 4 strokes at the top end .. and will try 69 this week ..

Looking for any other idea's

Any other work done to the engine or is it more or less a stock YD?

A proper pipe with a silencer on it can definitely help boost the performance a little.

How mechanically inclined are you? To get the most out of these engines you have to start getting into the engine a bit more. Port matching the lower engine case transfers to the cylinder transfers and cleaning up the ports can make a nice improvement in overall performance. Adjusting the squish gap (bumps up the compression) will also help to give a little bump to the performance. Port matching the intake and exhaust along with making sure the intake and transfers are left with a rough-ish (about 80 grit) finish.

All of that is the weekend warrior level of performance gains that can be had to help make an engine perform a bit better without getting into more complicated concepts and work.

 

[DAMIEN1307]

These 2 people are not even here in the forums any longer so I'm locking this thread to prevent any further reviving of ancient history here...lol

Any other work done to the engine or is it more or less a stock YD?