Yamaha KT100

[jd88x89]

Does anyone have any interests on working on the sound?  Jared?

Ill try, but the next chance is in 2 weeks @etown. Ill try. Just what do i need to do? let me know what u need.

[oppolo]

if it helps I found here the range temperature of a KT100

Yamaha KT-100 which operates in the 350°-420°F cylinder head temperature range and up to 15,000 rpms
http://www.redlineoil.com/content/files/tech/Two-Stroke%20Technical%20Info.pdf

[Cory_Hayes]

they AVERAGE around 15600rpm, my friends and I can upload photos of our data if you don't believe me

[Nathan Dunnett]

Like I said, it depends heaps on how they are built. There are so many variables with the port cast and other adjustable items that the engine builder has at it's disposal (cylinder head shape, squish band size, port timing, different piston, piston skirt length, ring end gap, ignition timing, etc.) that you could get two engines doing the same times with different gearing, one revving to 14700 and the other revving to 16000.

[Cory_Hayes]

.....I have never seen any good person reving a kt100 at 14700rpm

[Clova414]

Its just different regulations, in the states no one revs above 14500 @ 400-420°f ... mostly due to the ignition and exhaust,  I don't know what your rules are over there but they're obviously different... no big deal, just different...I guess we'll all have to come to some kind of middle ground, or multiple classes...

[Nathan Dunnett]

.....I have never seen any good person reving a kt100 at 14700rpm

How can you know how many revs people are doing without seeing their data? I've run within 3-4 tenths of my home track's clubby light lap record on a green track with old tyres while only revving to 14800. That lap record was set last year during qualifying at the QLD open states by Ben Stewart against the likes of Joseph Mawson and Cian Fothergill. Seriously, there is no hard and fast rule about how much these engines should rev.

[Matthew McLean]

.....I have never seen any good person reving a kt100 at 14700rpm

How can you know how many revs people are doing without seeing their data? I've run within 3-4 tenths of my home track's clubby light lap record on a green track with old tyres while only revving to 14800. That lap record was set last year during qualifying at the QLD open states by Ben Stewart against the likes of Joseph Mawson and Cian Fothergill. Seriously, there is no hard and fast rule about how much these engines should rev.

I see your point but just because that record was set at a state title doesn't mean it's actually as good as what it could be. At a state title the track tends to slow down quite significantly because of the extra amounts of rubber on the track, so you can't really compare. There's a high chance that record would be beaten if all those drivers of Clubman Light went back there on a weekend where there is less rubber. But anyways, what does it matter if it revs that low at that track? The RPM range for the KT100S should be set to what it most commonly runs at all around the place, not what it runs at a club or two, right?

[Cory_Hayes]

just putting it out there, ask some engine builders, they say ATLEAST 15000rpm

[GhostriderPl]

miss my air cool F100 though 25,000

You are dreaming    25000 isn't Raceable........In Formula A we use up to 20000 (normally 19600) and in Formula Super A up to 22000......But not more because the Power goes down and the Engine heat up fast....I have 25000 when my chain broke and the Engine starts to fire without a Spark (like a Diesel)




Greetings, GhostriderPL

[Nathan Dunnett]

I see your point but just because that record was set at a state title doesn't mean it's actually as good as what it could be. At a state title the track tends to slow down quite significantly because of the extra amounts of rubber on the track, so you can't really compare. There's a high chance that record would be beaten if all those drivers of Clubman Light went back there on a weekend where there is less rubber. But anyways, what does it matter if it revs that low at that track? The RPM range for the KT100S should be set to what it most commonly runs at all around the place, not what it runs at a club or two, right?

It's actually Cian's home track, I'm pretty sure he held the previous record and he's raced here plenty. It was a ridiculously quick track, most classes broke their records by 1-2 tenths, senior national @ 150 beat the old junior national heavy record by like 2 tenths. That's beside the point though, I was pointing out that not all engines are best while revving high. This isn't a track that needs tall gearing either, my other engine revs quite a bit more. I agree that we are going to need to compromise, I'm just saying that the notion of needing to do high revs to be fast is wrong and counter productive.

just putting it out there, ask some engine builders, they say ATLEAST 15000rpm

I've spoken to plenty of engine builders, we build our own mostly. Your engine builder may say that, but that doesn't apply to every engine configuration and it certainly doesn't make it true just because an engine builder said it. I see people trying to make their engines hit a target max revs quite often both with the J and S engines when they don't realise they could pick up a bunch of time by working with the engine's strengths rather than forcing it to do things it can't.

[Top-Kart 92]

when are the Yamaha ready??

[Cory_Hayes]

most people I know always rev to 15000rpm +
Do you race opens or clubdays, if so how do you go

[Nathan Dunnett]

I've barely done any racing this year but last time I raced was at Bundaberg last month, I went shit because it was the first time driving my new kart and it was set up terribly but I was 0.2-0.3 off the pace against Cian Fothergill, Luke Flynn, Troy Loeskow and a few others. I've done testing since then and picked up heaps so we'll see how I go in two weeks at the QLD open. The time that I raced before that was just a club day at Gladstone, I had a clean sweep and beat the lap record by half a second. The time before that was in Bundaberg for the Mac Truck Challenge and I was the quickest there by 0.2 against Troy Loeskow but crashed out in the final. I'm not often seen at the back of the field if that's what you're wondering, I've got >40 trophies after 4 years of racing so I must be doing something right.

[Cory_Hayes]

ight, so what do you think national champions/state champions would rev to......put it this way, if we came to a conclusion that it is atleast 15000rpm, come on, that is pretty average for a clubby