rmorhan

My Feedback: (17)

thinking of 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 for this engine/ airframe combo?i,m running a jett ss 40 on my other dust with apc 8.75 x 7.5n but these won,t fit the spinner .what rpm should i see on the 9 x 9 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

Cyclic Hardover

My Feedback: (3)

I dont have that set up but do have a few Jetts. By looking at what yuo want, that Jett fire .50 with a 9/9 apc will be very impressive and sounds good.

Razor-RCU

My Feedback: (50)

I really like the SJ-50 and APC 9x9 on my Patriots, I figure you could use a pylon prop. for a bit more speed-like the 8.75x7.5. How about an 8x10?

I use Powermaster or Omega 15% and a K&B1L plug. (OS-8 works but may have rich midrange per Bob27)

I do not use spinners on Deltas (Anymore [X(]) I would use a spinner nut like the one Jett provides... Then it'd be much easier to switch props if you want to experiment or if you break one!

Cheers! Bob'll be along here in a minute--

Rudeboy

Exactly what FIRE 50 do you have...?

Sounds like you got a balanced spinner... the heavy side of the (spinner)backplate should line up with the light side of your crank (the side where the hole is)...

rmorhan

My Feedback: (17)

not sure what model it is, here,s a pic....what hole on the crank are you referring to? also a pic of my jett ss40 powered dust... thanks for the advice. rob m

Rudeboy

I'm referring to the intake port in the crank.

The hole creates an unbalance in the crank, which is not insignificant at high rpm levels... If you have got a counterbalanced spinner backplate, then the heavy side of the backplate should be on the same side as the intake port in the crank. This will, for a part, take care of the unbalance. All front intake FAI racing engines use counterbalanced spinners too, for this reason.

Hard to make out from the pic if it is actually counterbalanced.
My Jett counterbalanced spinner backplate has a piece of steel (or some other metal) glued into a machined slot at the rear side of the backplate.

I see no reason why you couldn't run heli fuel... but Jett recommends Powermaster, which has a 1/3 castor-2/3 synthetic oil package.
I use Rossi 8 or Nova Rossi 9 plugs on high rpm engines... they seem to last longer. These are very cold plugs. I haven't noticed any detrimental effects on idle when using 15% nitro.

The [link=http://www.jettengineering.com/]Jett website[/link] has excellent instructions on it... read them... You will find them under "Tech specs and Instructions"

rmorhan

My Feedback: (17)

the spinner backplate is milled out between the two holes at the bottom in the pic , so i,ll line this cutout opposite the crank cutout. your right it is hard to see.. i,ll check the jett website as well.. info much appreciated... take care...rob m