Two Stroke Motocross
Two Stroke Motocross Forum => Photos & Videos => Topic started by: JETZcorp on October 30, 2010, 03:16:49 AM
-
120 in the Woods at Dusk (http://www.youtube.com/watch?v=CPFJBHqXRLM#ws)
From the Description:
This video was taken rather a long time ago, on the same trip as the previous, "Meet the 120" video.
This was the second outing of the day, because there was still light, the bikes were in good shape (aside from my rear brake lever) and the gas was plentiful. As you'll be able to tell from watching the video, the 120 has a unique combination of very high torque (for a 115cc machine), an extremely low first gear, and a riding position rather far aft. This means that, at any point of his choosing, the rider may bring the front end of the bike into the air with a simple zap of power. No clutch is necessary. Normally I ride my 250 Husqvarna, which cannot do this, so understandably I was over-doing it a bit on the wheelies!
You'll also notice that the other bike featured in this video (a 1973 Yamaha 100MX, ridden by my dad) is extremely loud. We suspect that the pipe may not be properly tuned for the motor, and is thus doing what incorrect expansion chambers do, which is to make a lot of noise and not much else. The 120 is a far more powerful bike in every category except absolute red-line maximum horsepower (the 100 revs quite a bit higher), and is much quieter. Neither bike has a silencer or spark arrestor.
-
John, if you think this should be moved to non-Moto instead, just let me know and I'll re-post it there.
-
Hey Jet,
It's a video... so it's in the right place. No worries.
-
Is the downpipe stock on the Yamaha?
-
No, it's not a stock pipe. If you look at it in person it's actually pretty easy to tell it's not, because whoever put it on realized a little late that it wouldn't quite clear in one particular spot, and so he took a hammer and banged a big ol' dent in it so it would clear. Without the bike in front of me I can't remember what the troublesome pieces was, but I think it was probably the kickstarter when it comes all the way down, would have interfered with the pipe. The 120 actually has a similar problem, if the pedal (or whatever its called where you put your foot) on the starter isn't rotated out, it clangs against the pipe. So if your foot slips off the starter, it snaps back into the stow position and goes, "Clingggggg" on the pipe. Doesn't do any damage, just some random 120 trivia for all the loyal 120 followers out there. :P
-
How can you ride with so much noise in your helmet.
That hurt my ears and i was able to turn it down !!
What a racket.
-
Did youtube remove the 10 minutes limit or are you a partner now? :D
-
When you go to the uploader, you'll note they extended the limit to 15 minutes now! It's a big improvement in my book!
As for the noise, you're right! My 250 Husky isn't too loud, and the 120 honestly isn't very loud at all when you're on it (because it likes to fire its sound out that stinger like a goddamn laser) but that 100 Yamaha is too much to take. My ears would hurt, and I couldn't hear my own bike over that piercing scream. I like how the bike sounds, but it's simply too much of a good thing. I plan on wearing earplugs whenever he takes that bike out. I can do that, or I can just open up the 120 and commit to waiting half an hour for him at the next stop, but that would be unkind, and riding gravel roads really isn't all that fun unless you're doing it in formation.
-
I try to make all my bikes as quite as possible.I've never had a neighbour complain about noise, hikers don't seem to mind and when I encounter people on horse back the horses just stare at me rather then taking off like the pony express.
-
I try to make all my bikes as quite as possible.I've never had a neighbour complain about noise, hikers don't seem to mind and when I encounter people on horse back the horses just stare at me rather then taking off like the pony express.
Sachs trust me, we have all already tried to convince Jetz to quiet his bikes down. It's wasted effort as he insists nobody can hear them where they ride... :)
But I agree. It's one reason I have zero plans to swap out my stock KDX silencer even if I do go with a different pipe.
-
Cool, just saw the report that they extended to 15 minutes. Look like they will be removing the limit apparently the reason is to prevent ppl from uploading full movies. I actually thought it was to limit disk space usage. PPL were still uploading movies, just in segments. oh well, can't wait to see the limit being completely removed.
Actually I heard that Pro Circuit makes a PC Fatty MegaPhone pipe and a Vintage MegaPhone extension. Basically you can cut your stock pipe in the center of the expansion champer and add on the megaphone to the end. It's supposed to ampliy your exhaust sound by up to 20dB. Might make a nice addition to the 120s :)
-
That'd obviously kill the power. Now listen, if you guys can show me a way that I can actually make the 120 quiet, that don't crack the pipe in half, I'd love to hear it. The fact is, we have a silencer for it, and we put it on for one weekend and now the pipe is damaged as a result. Not to mention the fact that 20% of the power was gone and the bike looked supremely stupid. I'm happy to quiet down the Husky, but with the 120 it just sacrifices too much, if it can be done at all. This isn't a '98 YZ, you can't just waltz on down to the friendly local dealership and say, "What can I do to quiet down my 1967 Kawasaki 120, which is probably the only running example in the State of Oregon and has an expansion chamber custom-made by someone who has probably been dead 20 years?"
(http://i62.photobucket.com/albums/h119/JETZcorp/DSC02448.jpg)
-
C'mon now Jetz, you have the ability to fabricate an aluminum silencer,mount it correctly,modify the rotary valve and touch up the porting and in the end, create a silent and deadly fast uber-120. None of this beating around the bush and making excuses, we want to see your Kawasaki tuned to perfection, you can do it. ;D
-
Jeez, at that point I might as well put a damn turbocharger on the thing! And because it's a two-stroke, it already has the anti-lag system built right into the engine!
-
You've got lots of room.Cut off about 12" of stinger that's hanging out the end and mount a silencer.
Cool trails though.They look wide open.For the next vid,you should try them in 2nd or 3rd. ;)
-
Really nice looking trails, I have a few like that around my house, but if I rode them on the YZ I'd be arrested in about 10 minutes and have the bike impounded. Damn trail nazi's!!!
-
Put a bloody silencer on it. :-[
-
I would've loved to open the little beast up in second or third, but then I would lose the Yamaha and never see him again!
-
Jetz,
The stinger section of the pipe (the bit past the rear shocks) can be be cut off and a silencer fitted, as long as the final (tuned) length and the diameter of the pipe doesn't change the power and delivery will remain the same. Just be a whole lot quieter.
-
But the silencer is longer than the stinger, so it would have to change, right? Maybe it's difficult to tell from the pictures, but the stinger really isn't very long at all, I wouldn't call it any more than 6-7 inches. Are there silencers to be had that could be attached but maintain a tuned length that short? That's not a rhetorical question, I just don't remember seeing one that short. I'd also be very afraid of messing up. I mean, if I try cutting up the pipe and something goes wrong in some way, then I'm out one very hard-to-find pipe. I'd like to see the bike be less annoying to those who decide to go hiking in a riding park, but if it means making a permanent change to something irreplaceable, I don't know if I could bring myself to do it.
Then again, if something goes wrong it might be possible to re-weld the stinger back on, if it comes to that. I'll keep the idea in mind.