Why motorized bike engines have gotten weaker lately.
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- čas přidán 5. 09. 2024
- This is my conclusion as to why motorized bike engines have gotten weaker in the last few years and what I have done to remedy it. Thinner crankshafts have made for weaker primary compression. I have remedied this by decking the cases and bringing transfer duration down.
The good thing about a lighter crank (as long as it's strong enough) is that now, it has Less rotational mass. So the engine has less work to do turning it. Which will end up = more power. BUT only if you stuffed the case VS the heavier crank if both were stuffed to an equal case volume.. It's gonna be a very minimal difference/Increase. . But on a bigger 2 stroke motorcycle engine. The lighter crank difference would be more noticeable in power.....If a person already planned on balancing his crank, stuffing the case & port matching it. Then they'd be better off with the new lighter crank, that'll spin easier/faster.
That's why I like the yd100's for their bottom ends. The crank is thicker and the bearing journals are also beefier. I've personally never had issues with vibrations that was not engine mounted or chain alignment issues.
Completely lack of quality control by the overseas manufacturers.
Yes decking raises compression in head but not case… stuff the case a sheet of metal cut to shape to fit inside to take up space… this brings up case pressure.
Decking the case definitely brings up case compression. First off, it slightly lowers case volume the more you take off the deck, but the case volume lose is minuscule.
The real major way it brings up primary compression (case compression) is it lowers the transfer duration. A lower transfer duration will bring up primary compression.
I've noticed the same. I bought a couple of Grubee GT5 cranks (38mm stroke) that have much thicker crank webs than anything I've seen recently. Even the new YD100 crank I bought has thinner webs than that old GT5 crank. I'm planning on swapping the piston rods and use it on a saw hybrid.
Bro has hella cred with this one.
good video for the new guys
Got my kit.2021 model. Seems to have good torque. Runs good.
Seriously everything went down in quality during covid. Pre covid cranbrook had bigger tires and better welding. Later models have physically thinner/smaller tires and the one I got had one less ball bearing in the front wheel than my others. Bro loving your channel please keep it coming!
Thanks for this info my black brotha
Good information glad to see you back bro
Stuff your case to make yp the increase of volume.
How about getting rid of the extra space in the crank case by making some like big like washers...?...
If you did any work with the falcon 911 cylinders
That was supposed to say have you done any work with falcon 911 cm
Thanks for the informative video bro
What's is the proper torque specifications on the head bolt nuts? Also, do you use head gasket sealant?
No sealant on head gasket, 12ft lbs
A great video bro I love it
I gave my yd100 8 horsepower using a Zuma cylinder had to make it into a case Reed but at work one thing I did not like was the crank it was very small I had to stuff the case Don Butler Speed Shop has the right cranks I can vouch on that no need to stuff the yd100 no more those that don't believe yes this guy's telling the truth they're definitely getting smaller
Stuff the case🤙🏻
Doesn't need stuffed, it's 90% full
Also,the compression when it fires and suddenly stops; sends my ass flying forward off the seat.
More people buying. More indemand China making them quicker. More cash simple.