After almost a decade of nitro heli, I have almost decided that enough is enough. Perhaps it is time to move on to an electric-only fleet. The raptor 50 was sold a while back, the T-rex 700N is probably going to become a 700E in the future, but I don't really like the frame layout of the 700E.
Since the Beijing 2008 Olympics, nitro fuel has gotten really expensive. Not sure if it is LHS getting greedy or cost really increasing, but I honestly doubt it is the latter, considering that the strong SGD currency should be more than able to cushion most of the impact of cost increase.
It doesn't help that lipo from hobby city is getting cheaper and performing insanely well. The lipo on my 10s E-raptor are doing perfectly fine after 30cycles. If you live in the States, probably nitro heli is still cheaper to fly, considering that shipping from HK to US is expensive and 30% nitro can be gotten for under 20USD for club order which by-pass the greedy LHS.
Matters were made worse with the series of issues I had with my nitro heli, mainly because most of my nitro stuff are ageing. It was so bad that in one of the weeks, I only got 1 flight after making 3 trips to the field. Glow starter not working, starter not strong enough, starter battery not giving enough burst amp, fuel pump stuck...not to mention the stupidly heavy flightbox I have.
NEW STARTER
Starting a 90 size was never suppose to be easy, but I never thought it will be so difficult. I burned out my old starter and so got a graupner ECO-90 starter as a replacement. This is a really big and heavy starter compared to my previous starter. It supposedly have 238N-cm of torque on just 12V, which is close to the Sullivan Dynatron starter on 12V. Not bad for a $81 starter. Really powerful and strong. Unforunately, because it is so powerful, my thunder tiger hex starter shaft is just unable to start the engine without flying out from the starter cone cup. After a lot of effort and changing out the stock rubber cone for the K&S one, it is now ok, but still a bitch to get in.
Also, it seems that my old lead acid battery, both the 12v 7ah and 12v 12ah, are unable to sustain the current it can draw when starting the YS 91sr. That means new battery required. I ordered a 4S 5000mah 20C from hobbycity. Why 5000mah? Because 4s 5000mah is cheaper than all the other 4s 3000+mah 20C lipo. Cell IR of these 4s 5000mah 20C is around 1.3mohm/cell, measured using my Cellpro 10S. I used the stock 4mm bullets for connectors. This current setup works ok for the YS. I tried a 5s lipo which works great too.
NEW FUEL- Nitro Magic
I was first introduced to this fuel by my LHS. It was low smoke and made good power when engine temperature is close to normal running temp. However, there was one slight issue- It was made clear as water to showcase its purity. What that meant was that it is very hard to visually guage if your heli still have fuel when you are throwing it around the sky, unless you use a timer.
The "retail edition" now comes in green for 30% nitro and orange for 20% nitro. I got a case of the 30% to try and indeed, it does wake up the YS 91SR. Apparently I was told clear and pure version is still available. Not sure if it is just psychological or what, but the "green edition" seems to have lighter viscosity oil and slightly more smoke compared to the clear version that I tried. Anyway, I thought both perform well.
Only have one issue with this fuel. The container sucks. Firstly, the rectangular bottle, that nitro magic comes in, does not fit my flight box. Secondly, the cap they are using is not a standard coolpower/wildcat type, so I can't use my my old caps with nipple outlet for the fuel pump.
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