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They'll be useful for years if well cared for and maintained CORRECTLY. I have a few 05'/07' CR125's that are cool. "Sticker Mechanics" are just who they are.
Can we agree that this thread is to be about what the OP intended? Thanks.
The Shop
Rod kits are scarce so crank halves usually have to be bored to accept the later 79-84 CR and RM 125 rod kits with larger diameter crank pins and lower rod bearings. Hard to find anyone willing to do those.
NOS matched sets of cases are top priority.
And of course when all else fails just reach for a complete NOS off the shelf engine.
I’ll admit, I may have a bit of a “problem”.
https://transmoto.com.au/bike-ricky-johnsons-1986-honda-rc250/
I guess Young's Modulus applies throughout engine life: https://en.wikipedia.org/wiki/Young%27s_modulus. And... http://www.scienceclarified.com/everyday/Real-Life-Physics-Vol-2/Elasti…
Nuthin' lasts forever. We only hope for the best and stave it off as best possible.
But in the spirit of the OP, he's dealing with hopped up stuff...Top performance. I have dealt with "punky" cases... No "ting" when tapped. Just "thud". My 125cc Kart bro taught me that. But WTF did he know.
https://motocrossactionmag.com/two-stroke-tuesday-grant-lanstons-works-…
KTM's plastics designs were and are incredible.
Fucking awesome stuff Derek
I heard that the aprilia gp team replaced exhausts every race so that they had no build up inside
Nova racing also make one off gearbox parts
The more you know the more you realise you don’t know !
I'll admit that a motorcycle forum is probably not the place for talking about feelings, but real men absolutely should "share their emotions", and to claim otherwise is dangerous.
Pit Row
I'd like to ask Derek what he thinks of the above, and specifically of technology like that found in the RK tek head? For those that haven't seen it, it has radial grooves that claim to increase power and fuel mileage.
Derek & the other techy guys knowledge gives me a new respect for the YZ125 and KTM 125/150. We look at two strokes as archaic technology but its fascinating to see that these things were developed to be the best all around package for most people.
Anybody have a nest egg or a KTM 125 they want to donate to the cause? Then we could all meet at a good track and take turns riding it. On second thought MXA would probably get their hands on it before us and hand it back in pieces, NVM.
Sadly all of Jan's work was to design an engine around a pipe configuration...which is really backwards. The RSW/RSA pipe were not that special apparently, but Jan had to make due cause the almighty head of the R&D team was the one who created the pipe. If it was reversed, who knows how much power the RSA would have made.
Frits Overmars said that 125 2 stroke GP development was achieving about 1hp a year...so the RSA stopped in 2007 with 55-56hp. That would mean that if they were still developing the GP125's they would most likely be around 65hp now.
And again, sadly when the 125 2 stroke program closed, Jan said that there were still things he wanted to try. He even had a new cylinder that was just casted, with the Exh Port floor level to the top of the transfers. When he got word of the closing down of the program, he went down the foundry and destroyed the castings... He never got a chance to try them.
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