jett fire 50 ?
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jett fire 50 ?
putting a jett fire 50 on my diamond dust. all i,ve got on hand that will fit the spinner is an apc 9x9. is there a better prop ?what rpm should i see on this prop? can i run 15 or 30 % heli fuel through this beast ? what,s the best fuel? there.s a cut out on the spinner back plate , should i line the cutout opposite the piston (ie piston at tdc , cut out at bottom ?? whats the best glow plug for this mill ?any advice appreciated....thanks rob m
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RE: jett fire 50 ?
Hi Rob,
Thanks for writing.
Engine instructions and information on fuel/plug/props can be found on the Jett web site in the TECH section.
It appears you may have counter-balanced spinner. Instructions for that are on the web site too. It is very important that it be installed correctly or it will shake the living daylights out of the engine/plane.
The JETT-FIRE .50 you have there is fairly late model. It has a welded pipe assembly, which was pre-tuned by Dub for a specific rpm range (somewhat tight range with such a setup), which makes it a bit unique from the standard SJ-50 setup. Dub would have provided the engine setup information and the recommended props with the engine when it was first delivered.
Typically engines set up like this for DD or Whiplash use are tuned for 18,000 rpm (or higher in some cases). You have to select a prop that can get there. Usually the APC std blade 9x8 is ok, and we recommend the APC D-1 series Q-500 props, usually 8.75x9W is a good place to start. A standard blade apc 9x9 may be a bit too much. You can try it, but if the engine does not get up to rpm, acts goofy trying to set the needle, or gets hot, throttle back and shut it off..... too much prop.
Plug, I recommend the K&B1-L std long, Rossi 3,4, Merlin Hot, MC-55 and 59.
Fuel, 15% standard sport fuel is pleanty. Heli fuel is ok. The 30% fuel is ok if you want to use it, but we typically do not recommend more than 15% because the engines were set up for that fuel when delivered.
Let me know how things go
Bob
Thanks for writing.
Engine instructions and information on fuel/plug/props can be found on the Jett web site in the TECH section.
It appears you may have counter-balanced spinner. Instructions for that are on the web site too. It is very important that it be installed correctly or it will shake the living daylights out of the engine/plane.
The JETT-FIRE .50 you have there is fairly late model. It has a welded pipe assembly, which was pre-tuned by Dub for a specific rpm range (somewhat tight range with such a setup), which makes it a bit unique from the standard SJ-50 setup. Dub would have provided the engine setup information and the recommended props with the engine when it was first delivered.
Typically engines set up like this for DD or Whiplash use are tuned for 18,000 rpm (or higher in some cases). You have to select a prop that can get there. Usually the APC std blade 9x8 is ok, and we recommend the APC D-1 series Q-500 props, usually 8.75x9W is a good place to start. A standard blade apc 9x9 may be a bit too much. You can try it, but if the engine does not get up to rpm, acts goofy trying to set the needle, or gets hot, throttle back and shut it off..... too much prop.
Plug, I recommend the K&B1-L std long, Rossi 3,4, Merlin Hot, MC-55 and 59.
Fuel, 15% standard sport fuel is pleanty. Heli fuel is ok. The 30% fuel is ok if you want to use it, but we typically do not recommend more than 15% because the engines were set up for that fuel when delivered.
Let me know how things go
Bob