[sweed speed]

For all you non rotax guys. My Leopard lost it's ignition in a fluke encounter rendering the engine useless. Does anyone have opinions on engines:
options include:
Rok
Super Rok
IAME KF2 (seems a bit overkill)
IAME KF3
IAME x-30

thoughts and opinions are appreciated.

Thanks,
Sweed Speed

[Mikko Nassi]

A new ignition ?

I only have experience of KF1 and the standard Rok in addition to a very fast leopard so can't really compare your choices. I guess it depends on how fast you want to go and what the budget is.

Are you racing them? If yes then the weight limits come into play in terms of competitiveness. A lighter kart is always more fun to drive.

[sweed speed]

Thanks,

I'd love to just get a new ignition, but Leopards are limited here it Taiwan. I hand carried the engine back from the states last year and have yet to find replacement parts.

The KF series engines are heavily weighted (168-170kg) where the PRD and Rok are 158kg.

I do race them competitively but now the season is winding down, I'm noticing more blown KF-2's and Roks with bad rings and pistons. If I'm going to invest close to $3,000 USD I'd like my engine to last a 7race season without doing an overhaul

I have all winter to decide so still weighing options...

[JohnKing6]

or if you're ever in Malaysia, drop into my shop, I have a complete Leopard which has been gathering dust for the last 3 years. You're welcome to it for a token cost (so I can buy a new paperweight....)

[pistole]

If I'm going to invest close to $3,000 USD I'd like my engine to last a 7 race season without doing an overhaul

- your engine can do a 7 race season without needing to be opened up ?

- the big end con-rod bearing on my rotax let go at about 35 hours .... and it was supposed to be able to do 80 ... agk.

.

[jonnexport]

Sweed Speed,
I would like to hear from you what how you lost the ignition.
For the other side Leopard, Vortex, Firebal, I mean, all TAG engines should to run under de TAG Racing USA Rules. So. they should to run with differents weight (kart, engine and driver) in order to be equalized.
You cannot compare the TAGs engines with the KFs. The KFs are stronger, they are better built and they carry all good new things that the TAG had in bad. Also, the KF1, KF2 and KF3 have limiter RPM rev whcih cut the RPM in 14000, 15000 or 16000. In Leopards we use to get 17000 RPM but IAME says that is not good (who cares anyway? This is racing).
Also, the KFs are open to carburetors brands besides being restrited to the venturi size. So, you cannot compare the Tillotson 334 or Triton with the IBEA, JHC or the news HW Tillotson.
Power by power (to comment about your question) Vortex ROK is faster than Leopard 09. Leopard it was launched in 2006/2007. In 2008 they did some changes and 2009 they rebuilt the low part of the engine where they add a conrod balance system, and they improve the whole clutch (engine sprocket with four screws instead three, a clutch pin to avoid spinning when loosing and (for some countries) the third bearing at the clutch guard to avoid the vibration which was the main problem to damage the starter. They also improve the wire system and the start. However they bring together another problem: the amount of fail to start is impressive. Everybody who bought one Leopard use to buy a spare wire and ECU.
For last don't fool yourself: that guys saying they can run 20 hours in a Rotax cannot be competitive. Rotax is the most expensive series in the world for so many reasons including fact you cannot brijng the engine to be rebuild for your mechanic or for yourself (if you could). Just make three races and practices that you will need to set up your equipment for each race. After that ask for your mechanic (or Rotax Center) measure your compression and you will see. There is another thing: you have to be very friend of Rotax Services because after running 10 hours you will need to clean the piston head since mostly technical DQs happpen because the squish is out. You never will be compettive if not making the right things to take the best performance. There is that driver who win and those who only run.....

[James Leong]

Personally, I don't know much about ROK or the IAME as I don't deal with them. Your comments on the Rotax deserves an answer from us in relation to what you said. Rotax engines can run for 50 hours without maintenance if you use it for hobby driving and for those weekend warriors. If you use the engine for "competition" our advise is always after every race to open up the engine at least the top part to check the piston and rings. Once you have opened it up then it is always advisable to sand off the carbon deposit on the top of the piston. However, if you use a good 2T, the chances of carbon buildup is very little. You have carbon deposit is because of the 2T. Certain 2T has a lot of carbon deposit on the piston while the better grades of 2T does not leave any carbon deposit.

There is a specification listed in the Rotax specs that gives you the max and min squish clearance. If you follow this rule, even with some carbon deposit you will not exceed the specs and thereby getting disqualified in a race. Most of the time when a driver gets DQ because of the squish it is because they have adjusted the clearance to the minimum. If you have problems with your Max engine, let us know. We will be most happy to help you out.

James Leong