Kyle Communications

Nothing of course but you know Skippy

Anything that rotates needs to be balanced especially in a high rpm engine. The crank is rotated at speed held in journals and the machine tells you what position and how much to either take off or add on in those spots. Its pretty simple really when you have invested the time and money into the equipment to do the job properly. You balance your car tyres dont you? well why doesnt Rotax balance their flywheels. We have tried more than 10 flywheels and all are not even close to being balanced. The flywheel is just one part of a assembly that when all added together hopefully has a vibrational level that doesnt cause extra wear or pressure on the rest of the components

The engines have been "blueprinted" pistons all weighed and made the same crankshaft balanced conrods weighed and made the same. The whole assembly balanced on a running balancer. I can assure you Turbo I know what I am talking about. Including balancing model jet turbines with my own 100k Schenck balancer I was balancing turbines that ran at 250,000 rpm. I do know just a little bit about balancing...oh and also I used to fix engine balancers for motor builders too.

Agree to disagree You do you and I will do me

2000 hours of operation is not a lot of hours at all Put it into perspective. you drive your car an hour to work and a hour to home so 2 hrs a day 5 days a week. so thats 10 hrs a week. So thats 520hrs a year plus all other private driving which could possibly be that again for holidays and visits and days to the beach etc etc so say 1000 hours a year. According to rotax you need to renegine your car every 2 years A car engine does not do the rpm or have anywhere near the stress on it of course but numbers are numbers. I know of many rotax 912 that are 5000 hrs and have not been overhauled and that can be very true but I also know of quite a few that have gone bang for various reason like camshafts and cam bearings and case fretting etc etc in less than 2000 hours as well Rotax are not perfect but my opinion is they shopuld be much better for the money we pay for them

Do what you want to do Skippy and stop having a whinge about it..you either do it or stop creating internet slop. Arguing about it is a waste of time. Unless of course you want to be king of the opinion brigade. People will do what they want. You have no intention of doing it so why even comment

I can tell you from fact and engine rebuilds that the flywheels are no where near balanced. That was on 2 of my engines and since then we have looked at a lot others and none are balanced. I have the access to the equipment and the expertise to have this done. When you pay 40k or a std 912 and 70k for a 915 and 90k for a 916 then I would be expecting to have at least the flywheel balanced But as I said Rotax base everything on 2000 hr operation...then buy a new one

Ok then the tacho is more stable at idle..there is imperical evidence for you. Depends on where you live. Warm up times can be quite long depending on temperature. Did you also know that no Rotax 912 or even other series have the flywheel balanced. You have a engine that does 5800 rpm in a aircraft and it is not even balanced? Rotax dont do that so why should they improve a crossover pipe..they just need "something" to balance the manifolds. There are lots of things that Rotax could and should improve but they dont.....and do you know why? Because they say after 2000 hrs you throw it away and buy another one. Thats why they dont improve anything

The idle sounds and feels better...cant quantify it any better than that.

I dont know why there is so much text on this matter. You set the mechanical side of the carbs up with idle stops etc then just do the carb balance with either gauges or a carbmate. Problem done. Except of course that the pneumatic balance will shift over time and thats because most rotax installs...that use carbs use the stupid bowden cables that can change their length then your balance goes out. The larger balance tube does give a better idle performance once everything is setup correctly. I have tested this and 3 or 4 of us locals have it done and yes it makes a difference. But you still have to do a carb balance with the vacuum and check the bowden cables..There are other things you can do to make it easier but thats another story

Well there are lots of claims that seem too good to be true...maybe this is just another one.....as usual time will tell

I just used AI but the figures are correct. 3dB loss is half so if your putting out 10 watts of power out of the radio then you are losing 5watts in transmit and half of the strength of the recived signal So it depends of course how long a run of coax you use. The shorter the better and every dB counts The cost difference is not a lot between both types. I know which one I will always use. Mark At 126 MHz (the aviation band), RG400 coaxial cable has an estimated signal loss (attenuation) of approximately 14.3 to 14.5 dB per 100 meters (roughly 4.4 to 4.5 dB per 100 feet). At 126 MHz (common for aviation communications), standard RG58 coaxial cable typically exhibits a signal loss (attenuation) of approximately 17.5 to 19.5 dB per 100 meters (roughly 5.3 to 6.0 dB per 100 feet).

RG59 is 75 ohm coax NOT 50 ohm. RG400 is what you need to be using. Its a double shielded teflon coax at 50 ohms. Less loss that RG58 which is 50 ohm coax.