Great video, I just bought one of these engines in unknown condition. I came here to find carb settings and general tuning info. You nailed it and alot of useful information here. Thanks!
KT100 is the most popular category on the karting circuit in Japan. Particularly cadet and junior classes. Check out the Ishino circuit in Toyota, Japan, Mizunami circuit, Gifu, Japan and Suzuka circuit (karting), Mie, Japan. Japanese karters always use 'minutes' when setting their low and high on the carb.
@@kart6t3_ben A suggestion for a video. You should do a video for the guys who don't know anything about karts. How the motor mount to the kart. How to change gears/ bearings. How the throttle works from the pedal to the carb. How the brakes work. How the front spindles work and how to change those bearing. Tire and wheel sizes to just get it going without worrying about stagger. Tools you are going to need to bring. What gears to get them going. Drum and disk clutches. Gear ratio chart. Those are questions I see on bob's all the time and if a guy is asking how to change a gear out 40 people can comment on there how to do it but without the visual learning he's not gonna comprehend it. Just a bare bones lesson to help the new guys. Would be extremely nice to have that visual representation to show a guy just not getting it.
I grew up racing kt100s down south with my dad ..in the late 90s early 2000s they were the fastest kart out there ..... . and now you can't even find one around Pennsylvania . So I moved on to cr500s and kx500s PA wings 💪 I hope outlaw karts build up your way as well
you can def find kt100 in PA. local here and hunterstown speedway / keystone state series will have a good amount every week. im sure you can come down and find yourself a good race. ill actually start running it next year at 13/14.
@@jantzen92 see! I try to spread the good word and everyone calls me a liar ! Gotta go down to hunterstown to find the kt100 boys . I'll pick me up some this summer. I'm 225 pounds and 6,1 so me and clutches in a kt100 have never got along sense the 90s when I was 95 pounds
The Yamaha KT100 class is not dead, you are just not looking in the right places! The VKCA and VKA (vintage karting) both have very large participation of KT100 powered karts participating including dual Yamahas. Some of the clubs here in California run a vintage KT100 class once a month and it gets huge turnouts.
where in California are you seeing these clubs? trying to get into go karting and these HPV 100s are pretty affordable and much for fun than the lo206 class.
Used to run one of these on a lil micro sprint car I raced as a kid, was choked down a bit per the rules with a can muffler however, we had one of the ole "wet" clutch's on outlrs but the guys who had money all had a "dry" clutch on theirs which was the newest technology, there was actually quite a bit of a difference in the two, also.... There was a good bit of difference in just a stock-ish engine and then one of these engines that had been sent off to be blueprinted, I think if I remember right a blueprinted engine would or could have up to like 3-4 more hp than a stock one, we always ran the head temp sensor on ours and man there was a fine line regarding engine temp, below 400 degrees and there just wasn't any power really, 400-415 and she was RIGHT and then anything over 420 for lore than say 15 seconds and you were using brick acid to get the melted aluminum rings off the cylinder walls haha, the last year we raced it they made a rule change and we actually ran them on alcohol instead of gas, there might have been a slight increase in power with the alcohol but it wasn't much, that year we blew more motors than we ever had really and could not figure out why and at the end of the season when my dad was taking everything apart to clean it to sell the car he found that the adjuster had gotten stripped from the screw itself in the carburetor so it appeared as though when I would turn the adjuster that it was doing its thing but actually inside of the carburetor it wasn't doing a damn thing, which I'm actually sure that it was probably able to do a little bit of adjusting because sometimes we would blow motors and sometimes we wouldn't but yeah that was a headache and a half for sure
As always great information.a few of us old UAS guys are trying to bring back the KT 100 in its own class down here in good ol Fl. With a jack shaft set up like yours . I’m with you thinking why has this gone extinct? It’s a simple set up and fun
Can be a couple things but usually spring pressure. If you do not have a spring height tool what you can do is make 1/4 turn adjustments on every spring and test it in between on the ground. Do this till you get it close. 9500-10500 is where I like mine. Clockwise = higher engagement (increasing pressure) counter clockwise = lower engagement (reliving pressure).
Hey I’m picking up a couple karts tomorrow and one is a kt100. My idea is that I wanna make a dirt track in my back yard for fun. What can you tell me about the kt100 that will make it fun to rip around with a 250lb driver? What or where do I need to look to get it so it will be fun on a small backyard dirt track? Thanks!
I might run it a little richer then a race application to keep the cylinder cooler. Possibly run the clutch engagement a tick lowe as well. I’ve never run one like this so I’m only guessing.
I recently purchased a Birel kt100 cart , everything is new on it . The engine is by Stafford Race Engines and its never been started since installed . Has anyone ever heard of Stafford Race Engines , I'm in Michigan and can't seem to locate them. Thanks !
What size of Lower Mounts do you run with the KT/Jackshaft Setup? Been running modified clones... Sold them all and bought 2 KTs!!! Love the 2 strokes and going back to my roots👌👌👌
Is there a good video that explains the performance, power, and character differences between running pipes and cans? I would assume the pipe creates more compression and thus more power. We always ran Redline, and there are times when I can remember the smell.
Oh that’s a good question. Finding an expansion chamber (exhaust) that’s straight would be something to look at. I’d prefer to be on some sort of jackshaft system to not melt down an engine clutch so easy also.
When you talk about clutch engagement speed, you say 10k crank speed. Does that mean you are only using a narrow RPM range of your engine (above 10k)? sorry, i'm new to this.
Engine rpm engagement. So on the particular setup 20/57 the clutch is turning 2.85 times slower then the engine. People can use different jackshaft ratios with the belt side so I always mention engine rpm engagement.
Hey what clutch do you think can last the longest without major maintenance? This is for a bone stock can pipe setup that’s supposed to be ran everyday for 6 hours straight
If your not concerned about giving up too much HP from rotational weight. A Gator 3disc or even better 4disc from Laukatis on a jackshaft would take that abuse I assume.
tell that to all of s2s in the west aussie wheatbelt mob, baldilocks mg reds + j with fly in carby > most of s2s with good running kts and decent tires @@kart6t3_ben
? On dirt bikes I've herd that engine braking or lifting of the throttle and let the motor in gear slow the bike down, was bad for the motor. The idea was that when you lift off throttle theres not a lot of fuel to lubricate the piston.. Dont know how much of it is truth.. Motocross 2 strokes and atvs have gears and wet clutches built into the bottom crank case. These use less pre mix because they run one quart of oil in a sump at the bottom of the gear casing. Which gives extra cooling to the crank case, gears and clutch. Plus they are water cooled with internal gear pumps and water jackets around the cylinders.
Interesting thoughts. Yes when your off the throttle on a two smoke the premixed fuel wouldn’t be plentiful. I’m not sure gear oil would transfer over on a two stroke (it’s not the same). On a 4 stroke engine case oil is always there (Honda has separate gear/bottom end oil). On karts we have a lot of sustained rpm is partly the reason for the 16:1 pre mix ratio.
Yeah. And the lifting only really apply to street riding or long rides were it is prolonged. When racing we only lift for a couple of seconds so not a big deal.
Hey trying to get a class going at my local track, have a yami been sitting for 12 years now, i installed an egt, what kind of temps are you looking for, 1/3 mile dirt
Hi I was wondering I have this Yamaha KT100 but I need a new clutch the ones I've seen for sale is around 450$ USD I live in Canada is this a accurate price or can I buy a certain clutch for it that isn't an arm and leg lol thankyou! 🤟😅
No shifter. Centrifugal clutch, so the engagement comes in a peak Hp. This also allows the kart to “freewheel” into the corner without a engine break with direct drive or shifter gears.
