whatsuppeter

I just put together an Inferno mp 7.5 sport with a stock GS21R engine. After the break in, I'm using 20% nitro fuel and the average temp. is around 250-270F.......on a sunny day. My question is.....is this okay?? I've heard they run a littler warmer, but the tech help at Kyosho said that Kyosho doesn't give temp. ranges for their engines. Do all engines have the same temp. ranges??? If it isn't okay....then what can I do to bring the heat down?? Does anybody have this engine, and do they just run hot?? Any comments would greatly help, because I'm very new to this, but already love it!!

Also, what will give me the best "bottom end punch" or quick acceleration off the line? I was told that switching to a 3-piece clutch with alum. shoes would help???? Is this correct and is there any other things that will give me what I want?? Thanks for any and all help!!!!!

nitrofan

I dont know about that Kyosho engine, but I do not like to let my Ofnas get above 250 if I can help it. Also what brand of fuel are you running. "Race" fuels often have less oil in them than "standard" fuels causing the engine to run a little hotter. the fix could be a simple tuning issue, though. If you are fairly new to tuning a nitro engine you may have it too lean. engines make the max power with a very lean fuel mix, but this causes hot running and short engine life. If you cant see smoke out the exhaust pipe all the way through the rev range, then you need to richen the high-speed neddle a little bit. Loosen (counter-clockwise) the high speed screw about 1/8 of a turn and try it again. This should lower temps some. continue to do this until smoke can be seen out the pipe at all times and the engine drops below 250. You may lose a little bit of power, but your engine will last alot longer that way, and the power loss is not all that large. I do not recommend running the engine at max-lean condition unless you can afford to replace the piston and sleeve every 2 gallons of fuel.

Kuma

My Feedback: (1)

If you're just bashing around with the car, 220-240 is adequet, if you can keep it around 200 that's perfect and you'll still get decent power out of it while it can last longer but it'll drink a bit more fuel. I kept my GS 21B01 around 192-228 at most times and around 250 during races.

BTW, my father has a Inferno Sport and upgraded shock towers, steering block and added CNC braces, helps the car's stability dramatically, I'm looking to fitting an older OFNA center diff (with metal gear) in replacement of his plastic gear and see how it'll run.

earthspeedandfire

i can't figure out was wrong with rtr inferno i will hold a tune for a little bit but then the next time i start it it will idle than the idle will go up like crazy and it sounds like its wide open, ive tried richening and leaning it over two turn and it doesn't help. any help figuring wats wrong would b great

(no leaks in tank/line)

teamselpats

oddly enough the same exact thing is happening on my inferno sport. Any help would be greatly appreciated

mr_grumble

Yeah look, my GX21 doesn't rock until about 280, and I know thats not good but its the way these were designed, ie they don't have a chrome bore resulting in more friction, etc etc.
These engines don't last forever based on this alone, but while they still go, change the glow pulg to a OS A5, much cooler than the A3 and it should help with the impossible starting when there hot.
As for the unstable revs, sounds like you either have air getting into the fuel lines, ie occasionally leaning out the mix causing the revving, or you have some crap somewhere in the carb. Might pay to pull it apart and give it a clean. But really, start considering a new engine. I replaced my GX 21 with a Hyper 21 8 port which I picked up brand new for $100 US and it kicks butt. 1.9 Hp Vs 2.5 Hp......need I say anymore....
Good luck