Rotax, Leopard OR____ engine for Senior TAG class and why ?

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  • #40213
    Zev
    Participant

    I apologize in advance if I am starting a firestorm !!

    I have a kart coming next week, want to sell the KT100 motor and buy an excellent used motor for Senior TAG racing.

    I am being told that Rotax is excellent and allows racing in Rotax Max series as well which sounds appealing (at least in theory).

    I am also hearing that the Leopard motor is great but each motor will feel different on different tracks.

    I doo not understand the reasoning behind adding weight on the Rotax and whether that applies to the Leopard.

    So far the best deal I have found is a lightly used Rotax (less than 10 hours) still under waranty for $1850.00 I am looking for a killer deal; any help will be appreciated.

    #46303
    Marc Elliott
    Participant

    My opinion
    Leopard

    Can do own maintaince.
    National Array of dealers and parts
    Cheaper then Rotax
    More of a useable powerband
    No rev limiter (great as long as common sense is used)
    No need to buy 300 bucks worth of dellorto jets, can be tuned on the go
    no seal
    tunable exhaust (rotax has this too, but no maintance for the flex pipe)
    charges itself (no need for 4 batteries, and no chargin between heats)
    good radiator, external water pump, great becase its not apart of the motor
    Great torque for a two stroke,

    Each motor is weighted differant becuase the weights are an attempt to equal the motors based on tested HP
    let me know any other questions

    #46304
    Zev
    Participant

    the Rotax contingent please !!

    BTW..it looks like I am in luck…the friend selling me the kart from Indy is most likely able to sell the KT100 motor,motormount and new clutch to someone local. That leaves me with the killer Trackmagic chassis and Brembos for closer to $1000 😮

    @Marc Elliott wrote:

    My opinion
    Leopard

    Can do own maintaince.
    National Array of dealers and parts
    Cheaper then Rotax
    More of a useable powerband
    No rev limiter (great as long as common sense is used)
    No need to buy 300 bucks worth of dellorto jets, can be tuned on the go
    no seal
    tunable exhaust (rotax has this too, but no maintance for the flex pipe)
    charges itself (no need for 4 batteries, and no chargin between heats)
    good radiator, external water pump, great becase its not apart of the motor
    Great torque for a two stroke,

    Each motor is weighted differant becuase the weights are an attempt to equal the motors based on tested HP
    let me know any other questions

    #46305
    Anonymous
    Inactive

    I’d go Rotax.

    You DO have to send the motor to a service center for a rebuild, but that means you have to carry fewer spares than say a leopard owner that wants to be able to rebuild his motor at the track. In the event you have to have the motor rebuild a good shop should have fast turn around, we send ours to Curtis @ Acceleration Karting in Vegas, and have had a motor back to us in as little as 4 days. My motor has approx 25 hours on it and I raced 15 races last year including 2 national events, and have had 2 full winters of testing on it. And it still runs as strong as when it was new.

    You WILL need an assortment of jets, but if you find a used motor most owners will already have them. If you can’t get spares with the motor and plan on running in CO you should get the 165,162,160,158,155,152 jets, they will be enough to get close on jetting they can be found for 4-5$ each. During the hot months we never went higher than 158 and occationally dropped to a 150. If you travel to lower elevations to race you will want a few others, but the jets I mentioned will be fine for running in CO.

    In my opinion the powerband isn’t any more or less usable than the other motors, but it is more a matter of how good the driver is at using the power available to him. A rotax will reward a smooth driver. Where a leopard or biland should favor a driver who likes to through the kart around and srub speed in corners. Those motors tend to have a bit more low end power to pull them out of corners.

    You can run a rotax with only one battery, the only time I’ve had to charge mine between heats was when I was being a jack@$$ and forgot to turn the ignition off the night before the race. It is always a good idea to have a spare but 4 is a bit extreme.

    The rotax does offer the benefit of a very strong national program. We now have 2 qualification series you could to choose to run, to qualify for nats (which are in Vegas this year 😀 ) CRE has a series as well as GJ. If you want to run national level events, with the rotax you have the option of running TAG @ SKUSA Pro-Moto events or the Rotax Max Challenge. I have yet to run a PMT event but I did attend RMC nats last year in Denton TX, and the competition was INTENSE!!! the top 37 international class drivers qualified within 1 sec. of each other! 😯

    I have a biased opinion, but I’d choose the rotax. It is very capable of winning CSC races, I won the only CSC race I was able to attend last year. Dennis Garwood won the series championship with one, along with a few races along the way. And it offers you a few nice options if at some point you want to run at the national level.

    #46306
    Anonymous
    Inactive

    Oh I forgot one thing, $1850 isn’t too bad of a price for a 10 hour motor. I have seen then in as low as $1500 with approx 15-20 hours on them. The popularity of the class can make used motors harder to find (which should tell you someting) but you can run across deals every so often.

    #46307
    Anonymous
    Inactive

    @Marc Elliott wrote:

    My opinion
    Leopard

    Can do own maintaince.
    National Array of dealers and parts
    No need to buy 300 bucks worth of dellorto jets, can be tuned on the go
    no seal
    charges itself (no need for 4 batteries, and no chargin between heats)

    I really see no issues with these if you are going to run in TaG.

    #1- You can work on your own kart. If you are only running TaG, it doesnt matter if there is a seal or not.

    #2- There is just as big of an array of dealers for parts. Probabily bigger.

    #3- Jets are $4/piece at IMI. You don’t NEED more than 10 of them up here in CO. Thats $40, not $400.

    #5- Once again, seal is not an issue if running TaG. No need to bring running Rotax Max into the argument since the Leopard can’t run in it anyways.

    #6- You only NEED one battery. Just plug it into the charger. Really isn’t an issue. Or have 2 batteries ($20-30/battery).

    I think either is fine. If buying new, I’d probabily get a Leopard, just because its a bit cheaper. But if you want the run in the Rotax Max series, then there is obviously no choice here.

    BTW, did you get the kart yet Zev?

    #46308
    Marc Elliott
    Participant

    Understandable however

    The sealing thing goes beyond just changing pistons, it prevents the reed cage and reed changing, which can be a pain if your reeds breake and you dont need a piston, and plan on RMC so you have to send it back. If you have a rotax and do not plan on racing RMC, w/o a seal, you are subject to teardown if there is a susspiction that you are cheating, without the seal, it can be a hassle. In RMC, you can only change the jets, not the emmulstion tubes, needles, piolts, etc. In Tag, jetting is open, with a rotax, you have to clean the powervalve often, and other things. The seal fee is $250 if you decide to put a seal back on for RMC, and things like that

    Not anti rotax, but i would like potential buyers to know the good points about a leopard. Either motor is good, and your choice is good. RMC is one of the best series internationally, but outhere, TAG is much stronger, whearas in South Africa, it is primally rotax run exclusivly and they have won the WC for the last 3 years, so that is their thing, but in CO, the TaG concept of motors seems to be the way to go.

    #46309
    stacey cook
    Participant

    Anyone needing Dellorto jets we have plenty at great prices. $2.50 each.

    #46310
    Anonymous
    Inactive

    Marc, $250 is cheap when you consider that you have to spend $2,600 to race the RMC if you have Leopard 😆

    Zev, if I was going to race Bandimere, I’d buy a Leopard, and I’d buy it from JB. I think he knows the most about that motor locally, and from what I’ve seen, he provides his customers with great service. The leopard package is basically a small carb that is easy to tune and an electronic system that allows for high RPM’s. This results in higher maintance, more piston and reed changes for the motor. It should be easier to tune, and easier to drive as you’re not as penalized as much as the Rotax if you don’t keep your RPM’s up in the corners. Where you’re going to lose time to the Rotax is at the end of the straight. The larger Carb on the Rotax simply allows for higher speeds at the end of the straight. However, the small carb makes for an easier to drive package.

    If I was racing IMI, or CRE, I’d go with the Rotax. I think it’s the motor that’s in the front most of the time on those tracks, and I’ve found the guys that race that motor very helpfull. As you know the Rotax come sealed, and with that seal you’ll spend less time in tech. The carb is what’s called a variable venturi carb. The result of that is that you’ll need to learn to roll on and roll off the throttle. Quick stabs on and off the carb will load up the motor and bog you out. It’s not easy to learn, but hey I’m almost there and I’m no brain surgeon. However, our local brain surgeon was still trying to figure it out that last time I raced with him :D. Over time I’ve learned to roll on the gas as I feel the motor pull.

    The jets take a few minutes to change, you usually need to change them during the race day, most guys are using the MaxJet software with a weather station to gauge jet choice. It’s an extra expense you should take into account. The other aspect of this motor is the power valve. It should result in faster acceleration than without it. It’s not on the Leopard. With the Rotax, you really need to stay within the 6000 – 11,000 power band, and within that, the 8,000 and above is where you really need to stay. If we had an adjustable clutch, you can adjust that, but we don’t, they lock up down around 4,000 rpm. What this means, is if you slow down in a tight corner, you’re going to get killed coming out of it. The Leopard has a higher stall speed, it’s therefore more forgiving. So if you can stay higher in the RPM band with higher cornering speeds, the Rotax is faster than the Leopard. But if you have tight corners like at Bandimere, the Leopard will have the advantage.

    However, if the CSC insists on giving the Sonic motor a big advantage by not adopting SKUSA weights for that motor, that would be the way to go. Also, by far the best HP for weight in the masters class is the Italsys with Electronic ignition. Who know why, buy that motor has at least 1.5 more peak HP, but no additional weight than the Leopard. I don’t know of any local support though, and if you’re new, local support should be your biggest deciding factor.

    I’m going to take a quick tangent here, the biggest thing I’ve learned is you’re going to be far better off buying a motor where you can get the best support. These little motors aren’t easy to keep runing, and you can save year’s of frustration if you buy your motor from someone that has good support. Of course, sometimes even when you do that, the shop can go out of business. 😥

    #46311
    Taylor Broekemeier
    Participant

    I’m surprised no one has offered the Sonik VX125 for recommendation, in my opinion, it’s the best on the track!
    There are many things i like about mine:
    -The cleanliness of the engine on the kart. The Rotax seems like a big pile of parts sittin on top of something that resembles an engine. The Sonik and Leopard have the radiator on the left side of the kart like a shifter. The Rotax puts the radiator right on top of the engine which makes me think that it might be diffucult to work around.
    -Like mentioned before, the external water pump is a plus on the Sonik and Leopard because if you don’t have much time to warm-up your engine, you just pull off the water pump belts and not let any water circulate. No harm done to the engine, just less time standing in front of the kart revving the engine.
    -One thing that influenced my decision to buy Sonik was the fact that it was developed out of IAME (Ital-American Motor Engineering). This was a factor because they have been developing kart engines for some time now and they probably know what they’re doing when it comes to engines. The Rotax is made by bombardier which is a great personal watercraft/ATV… enigne but it’s not really a name anyone associates with karts.
    -The Sonik has a great powerband. From about 7,000 all the way up to 18,000 rpm, it pulls hard! When i race IMI, on the back straight, no one can seem to keep up with me, it leaves the others in the dust!
    -And my favorite part about the Sonik is the exhaust note!!! It has a redline of 18,500 RPM and when it’s goin down that back straight at IMI, there’s nothing that sounds sweeter!

    In my opinion, go SONIK! Barry over at Billet Performance, sells ’em and offers the best service i’ve seen! 😀

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