Keep them alive? Pretty sure they are dead.

 

https://www.google.com/amp/dirtbikem...ers-guide/amp/

 

My comment was not directed to the disappearance of 2 stroke bikes, but to the fact that not much R&D is being done like it was back in the Pre-4 stroke hay day.

That list of bikes you linked to also clearly shows some off brand shady manufacturers that don't have bikes that compete on a pro level (with the exception of Stank Dog's recent out-door campaign this past year on a the Husky.

Only a very small portion of the R&D budgets get allocated to the 2 stroke stuff. With current AMA rules and those tree hugger **** at the EPA it just doesn't make sense. Hell, if if one of the Jap companies decided to focus on a 2 stroke mx/sx bike and ramp up R&D......it would likely be fruitless. The 4 stoke engines these days dominate anything 2 stoke ever made if both follow ama rules. \

 

I'm gonna share one of my engine building secrets here, just cause I'm feeling in a good mood and want to share one of the things I do to get max performance out of these things.

It is absolutely crucial that the piston coatings match the the engine case covers for generating max 2 stroke power lol

 

Gotcha. I am dreaming about getting a Yamaha YZ250X. As a woods rider, I think it would be perfect for me. Just plunk down my money and ride. No mods necessary, way better than my skill level. Although it is supposed to have the latest and greatest Japanese suspension, you are right about engine development. Just incremental improvements over the years.
I have to disagree about any of those manufacturers being shady. Maybe you are not familiar with the Spanish and I think Italian brands. They can't compete with the big companies, but they make quality stuff. Or maybe the small Jap two strokes are made in China? That would elicit being labeled "shady".

 

Except now I would have to tear it down and get the piston color-matched to the cases.

 

What kind of ring gap and piston/wall clearance are you shooting for on a build like this? I like **** like this. I had an 80's RS 175 back in the day that took more hide off my *** than anything else I've ever straddled.

I asked about machining capabilities for a very specific reason. I have an antique cylinder head that needs some work to go back on an engine. Not too crazy about turning just anybody loose with it and some cutting tools... maybe PM or Txt me and I'll fill you in on it. Don't wanna derail any of the 2 stroke goodness you have going on here

 

whenever you're ready........I know a guy

 

I typically follow Wiseco's recommendations. I've talked to a few of the old school guys (when I say old school I mean mid 90's to a few years after 2000). Depending on cylinder finish and expected run time they seem to favor a ring gap a bit tighter. However, these are the guys who where doing top ends in the pits after each race. I've measured ring gap on the supplied Wiseco rings from about 3 different top ends for this thing and they haven't been tight enough to touch so they have been getting installed as they come out of the box.

Regarding your antique project......I'd be more than happy to see if I can either get you fixed up or pointed in the right direction. I pm'd you my personal email and cell number. I don't sleep so hit me up whenever.......

 

I have been reading on this site for the past year because I am planning on building a turbo ls chevy of my own soon. There was no need for me to post because I dont know nearly as much about these trucks as everyone on this sight... Then I saw this motox build and I was stoked because I have been racing my entire life and qualified for a number of ama outdoor races and supercross events... That being said I think the bike you are building is turning out pretty nice but in the most respectful way possible is not nearly as special as your trying to hype it up to be... Since going thru a couple life threatening injuries and being lucky enough to get a very good job that i cant risk losing I have retired from my dream of making it as a underpaid struggling motocrosser... I am a huge two stroke fanatic, grew up racing yz80s, 125s, 250s and currently building a bad *** yz250. I dont know what happened between you and Derrick Harris but I will tell you that guy is by far the best most knowledgable engine builder there is period!!! He has built me and many other people the most insane engines around! He currently has by far the fastest most reliable yz144 package there is! Back in the day when Chad Reed was racing factory yz250s team yamaha was looking at what Derrick was doing because he was building faster engines then factory yamaha could! So I think you are way off base on that aspect... Sure Tom Morgan is one of the top porting guys but couldnt hold a candle to the custom billet cylinder, custom gear ratio billet transmission, custom single ring piston 60+ hp Non big bore engines Derrick builds!!! He has taught be so much its ridiculous! You want the fastest 250 two stroke built go to him! I dont know if you have seen the bike builds on vital but those are real as close to factory builds as they get! I mean your bike still has a regular 2ring wiseco, not even Akit suspension, regular triple clamps, no frame mods, no rmz subframe? I am currently building a yz250 kind of like yours rm. i did anodized black frame (powdercoat add pounds of weight!) custom build lightweight subframe, all titanium aluminum bolts on everything, yzf swingarm lighter more flex with holeshot linkage, custom lowered radiators and lightweight seat foam to lower cog, Akit 50mm showa suspension custom triples honda hspd damper,custom wheelset with tubeless tires, custom lightwheet plastics and graphics, custom billet calipers with motostuff rotors, the frame and engine mounts machined to tune more flex intoit to feel more like a steel frame yz and last but not least Derrick built engine just like chad reeds factory 2004 yz250 with chokeless magnesium carb! Your build is cool dont get me wrong but its nothing that special...