Gordy
Well-Known Member
I know my dirt bike helmet looks stupid after, but it is a must have for me
YD100 Top Speed
- Thread starter Search
- Start date
Majicfingers@1
Member
- Local time
- 4:57 PM
- Joined
- Aug 8, 2016
- Messages
- 89
Got mine up to 40 mph and its not broken in yet
Sidewinder Jerry
Well-Known Member
So you have a new bike??? Tell us about it.
I just want to state that the quote below is the most solid advice you have gotten.
Allow me to explain why I say that.
First, I have built a couple of YD100's. They are good engines overall, and yes you can get them pretty cheap. I've seen them for 120 bucks for just the engine and around $170-200 for a full kit. If you have the tools you can do the squish gap and port work adjustments to get them to produce more power, and they generally do need a decent amount of port work, especially on the exhaust side, but also on the transfers and intake too. Being a single piece cylinder makes the upper transfer work tricky, if it needs it... which is probaby will.
Assuming you have all the tools to do that work, no cost is added so far (which we know won't be the case) you will still need to add induction (carb and/or reed block) and an expansion chamber to really achieve those speeds beyond 40. I am sure somebody will say they did so without a chamber, and to that person I ask them to provide actual evidence and not an anecdote.
Essentially, to MAYBE do what a Phantom can do 100% bone stock, you will end up spending more money and a lot more time on a YD100.
I get if you want to walk your own path and do your own thing. Maybe, like me, you just like the challenge of taking something inferior and making it hold it's own against something "superior." If that is the case then by all means do it. I love to tinker like that too.
That being said, if you want it as more of a build project then why not do a Minarelli build? Get proper power whilst also having a good project to tinker around with and build.
francisjohn
Active Member
The truth about the YD100 is that the port timing is better for low end-mid. its easy to think "well a bigger bore means more power and speed" which isn't necessarily accurate. Take a 47mm bore minarelli versus a 47mm 66/69cc, the minarelli will perform night and day in comparison and while there are many factors in play (even the height of the piston rings) it comes down to the aggressive port map that comes on them.
This is why personally I do 47mm-49mm bores, and mod them, aside from the fact I enjoy two piece cylinders, I know what I'm getting into. The only reason to let's say go from a 47mm to a 50mm is in hopes of more speed, they do rev slightly higher don't get me wrong, but the port map is what makes or break it.
This is why personally I do 47mm-49mm bores, and mod them, aside from the fact I enjoy two piece cylinders, I know what I'm getting into. The only reason to let's say go from a 47mm to a 50mm is in hopes of more speed, they do rev slightly higher don't get me wrong, but the port map is what makes or break it.
Gordy
Well-Known Member
I want to build a 52mm saw engine with a yd100 bottom. It'll be some money and work, but it will be great once it's tuned
Just buy a Phantom 85 then, alot less work with more than enough power, you would be amazed and surprised, just like I was...lol.l
Gordy
Well-Known Member
I just want to have the satisfaction of working out the issues of building something that was never meant to go together, but makes an a$$ load of power
Stubborn little cuss, aren't ya...lol...lol.
Plenty of time to work smarter and lazier when you get older and wiser...lol...Like me...lol...lol.
