Anyone have the timingnumbers for the Kangaroo crank? Would be greatful if anyone can post the numbers for me :-)

Sorry, I do not have them. Over the years there were many versions of the Kangaroo and many engines were based on it like the NovaMega line and the JP R01. The current ISON is the follow up model.

And then if you want to place a Kangaroo crank in the crankcase of something different it is not to tell it will get the same timings because the crankcase hole under the carburator is also determing the timings. But will it work? yes.

Question for Roelof. I run at the Toledo track in USA, using the ISON 21 from NovaRossi. This track doesn't require long term RPM to make good laptimes. I am able to make the 5 minutes for qualifying and can drive the ISON very hard. Comparing to the NovaRossi Mito, is there an advantage to using the Mito over the ISON?

The Mito is rated with overall better specs so with the right gearing you should have more advantage. But yes, the ISON is from itself already a good engine that can be fast in the hands of a good driver. For sure on a more technical track the setup of the car and the level of the driver is more important

What temp is everyone running their mito .12's and .21's at? A buddy of mine said that they are running their .12's at 300--310! Back in the day this was a meltdown. Is this temp safe?

Thanks in advance.

That's too hot in my opinion.

I like to run mine at 160F plus the ambient temperature.

However I use temperature as a secondary measure. I tune on sound, feel and ensuring smoke out of the corners. I also look at the plug element as that's a really good way to check your tune is good. As a rule of thumb if you are getting good smoke out of the corners and the engine isn't running on after WOT then you aren't lean.

Thanks Dan. I'm assuming you meant 260°f?

Gixxer .12's usually run at 280-300. You wanna hear them singing!! .21's 210-220 is safe. Never wanna run them as hot as a .12. Always look for a nice trail of smoke on acceleration

No I meant 160F plus the ambient temperature so if the ambient is 80F then I'd be looking at running around 240-250F. I have never in all the years running.12's ever had to push an engine to 300F. The most I've gone to is 270F and that was in Thailand at the Worlds 2014 running indoors where the ambient was over 100F. The engines were new at the start of the week and knackered after that event. Run one lean at 300F and then check out the plug you'll see what I mean.

My current engines rin 135-145 degrees C

Target temp plus ambient? I've never heard of this. It does make sense in a way. Today running I really didn't get the engine hotter than 220° but is was only 55° out. It was running really good at this temp. Is this a common practice?

Mito35 Early failure
 

Gents,
So my first foray into Novarossi ownership did'nt end well. After careful running in (with help from local experts) for around a Gallon we changed the rod ready for the local GP. Warming up after 4 round of qualifying, this occurred (see pictures)

From my initial root cause analysis my current assumption is a slightly imperfect casting(cavity)/miss-machining/sloppy original bearing install, caused a small chip to eventually release in the area of 1 o'clock (engine upright) position of the front bearing. This chip made its merry way down the crank and up into the piston and liner. I found some small metallic chunks after flushing the engine (combo of different alloy materials).

My question is, is the little piece of missing material usually placed here as some sort of oil slot? It doesn't make sense to me and it's shape is more consistent with a small localized material release.

So the engine is toast all the way through, not really economically repairable. Funnily enough the other mito sold at the same time died of loosing the crankshaft counter weight during operation.

Please note I'm not having a 'chip' at novarossi here, these are highly toleranced and highly strung racing engines, this is just bad luck and manufacturing something like this is something of a dark art form! It's just a shame as the engine was awesome to drive, really smooth and knocked my lap times 0.5secs as I was much neater out corners. Luckily my old faithful reds wcs v3 (12 months old and zero maintenance except a few rods) kept its head up for the final (Thanks Mario Rossi!).

So happy for any expert opinions. Air filter was new and sticky, tie-wrapped to the carb, new fuel filter too. No signs of any distress there.

Kindest Regards,

Motor is ingesting a lot of dirt an debris. Either very dirty track or faulty/dirty filter setup probably.

Maybe a piece of dirt through the front bearing?

I would send the pics to Novarossi or the shop you did get it from and ask what they can do about it.

You can see the scoring around the crankshaft intake bore area. It looks to me like the engine was ingesting a lot of dirt. The scuff mark on the piston is also indicative of running lean. What fuel and temperature were you running the engine at? Usually if debris goes up the liner you get deeper scoring than this - the scuff (dark gray area) is indicative of running lean or bad fuel.

I agree with Roelof that you should take the engine to the place of purchase and ask them to contact novarossi about it because if it can be proven that the front bearing was defective (material came away and damaged the engine) perhaps they will help you out. Novarossi won't talk to you direct they only will respond through distributors.