nitro _ burner

Ok everyone here is a thread to post all your pics, questions, tips, links, discussions etc etc. On the Hyper ST.

Ev1er

Ok^
Is the hyper st rtr better than the hyper 8 rtr?

sirvancealott

The engine on mine has given me lots of trouble. Hard to tune and impossible to keep under 300 degrees. I'm switching motors.

nitro _ burner

Firstly the Hyper ST is a truggy and the Hyper 8 is a buggy.

nitro _ burner

Engines in RTR's are never the best but it shouldnt be giving you that much trouble, most people change thier RTR engines for more powerfull race tuned engines. Just make shure your running all the needles (LSN, HSN, and mid-range needle) in the factory settings then try again from there. remember not to adjust the Midrange needle. and adjust the LSN once you have tuned the HSN.

sirvancealott

I could not get the engine started at the factory needle settings, so I started to adjust from factory settings to get the engine running. Unfortunately, I did adjust the mid-range needle, but I realized my mistake, pulled of the main needle and re-set the mid-range needle back to flush with the carb body and carefully lining up the hole in the brass fittig inside the carb with the main needle. After that, the engine would run, but I had to lean the high speed needle to a point where it began to overheat to 300 degrees or more. Any effort to richen the high speed needle resulted in the engine bogging and running very poorly. After a little over a gallon of fuel, I fried the engine. I have ordered a Picco P3 .28 to replace the mac-star .28. I hope this engine will be more consistent and not overheat as much.

Joe RC

ya i'm in the same boat you are. The Mac star .28 is junk. Doesn't run worth a hell under 300 degrees and the temperature of the engine is so unconsistent. Looking at Nova Rossi and wondering why nobody runs o.s. max. Looking in the back of some of my magazines and in the truggy and buggy class o.s. is number one in most race results, just wondering why i don't hear about them on here?

sirvancealott

I'm sorry to hear that you are having trouble with the Mac Star .28, but it sure does feel good to know that its not just me. Even the magazine articles I've read on this Truggy state the engine tends to run hot. Once mine hit 385 degrees. That of course destroyed it. I'd love a Nova Rossi but its too pricey for me. I went with the picco .28 because seems like a better quality engine, and because its also marketed by Ofna I figured it would not be hard to switch into my Hyper ST. O.S. Engines have a good rep, but I couldn't find one in the .28 size. Maybe I did not look hard enough. Anyway, anthing is better than that Crap-Star.

nitro _ burner

Hmm this is the first that ive heard of the mac-star running realy hot, anyway it might of been your LSN set too rich......

Joe RC

Just curious "Sirvanceallot", is there somewhere on the internet you found the reviews for the hyper st? Just wondering because i have never read any reviews about it anywhere.

sirvancealott

I guess its possible the low speed needle was set to rich, but Joe RC said his was doing the same thing as mine. There are two articles, one in the May 2007 Issue of RC Car Action, one in Xtreme RC Cars for July 2007. Both articles say the engine runs at about 275 degrees to run properly.

sirvancealott

They were magazine articles. See my response to nitro-burner. He thinks the overheating could have been the low speed needle setting being too rich.

Foxy

Any needle being too rich is not going to cause overheating. I think you mean too lean. By the way, sirvancealot, you had an air leak in your mac-star or fuel system, I guarantee it. It's just about the only possible cause for the symptoms you describe.

sirvancealott

Thanks for your feed back. I didn'tunderstand how a rich low speed needle could cause oveheaing either, but that is what nitro burner said. Perhaps he meant lean. How can I determine if the leaky fuels system or engine is the cluprit and how can I determine where the weak link is? I definately don't want to burn another motor out! I blew air into my fuel line to check for leaks and I noticed that some air was escaping from the fuel tank lid, but whenI pressed the lid down hard, it would stop. Could this be the problem? Also, the high speed needle seat seamed to be leaking a small amount of fuel onto the carb body, so I put teflon ove the needle threads, but by that time the motor had already gone bad. Do you think these issues could cause the motor to burn out? Any recommended fixes?

Foxy

Leaky fuel tank lids are common and can cause an overlean condition due to the pressure from the line that leads from the exhaust to the fuel tank escaping through the leak, which results in a loss of the back pressure required for correct fuel delivery. I suggest you look into a fix or replacement for this, or you may indeed see your next motor going the way of the mac-star. Any leak from the carb needle seating would also be a worry, but not any more since you replaced the engine (and I'm assuming, the carb along with it). Fixes? Replace or repair the fuel tank if possible and check for other air leaks.

Have you run the new engine yet? Anything to report, or does it seem to be fine?

sirvancealott

Ok, I will probably replace the fuel tank. I am replacing the carb with the engine, but have not yet received the new engine. I'll let you know what happens.

Joe RC

Hey "Sirvancveallot", i blew in one of my fuel lines also and air came out of the top of the fuel tank like yours. Just try pushing down on the lid after each time you refuel. After i pushed down on the lid i blew in the line again and nothing came out. Just an idea that may work and be a little cheaper.

sirvancealott

Dude, I performed that same test on my lunch hour! LOL. I had identicle results. The lid is not closing all the way with the force of the spring. It needs to be pushed down to get it completely seated. I think Foxy may have headed us both in the right direction. I also read an article in RC Car Action that said you could put a little grease on the seal of the lid to help it close all the way. Let me know if this fixes your problem, as I'll have to wait until my new engine arrives before I can confirm this was the cause of the erradic engine performance.

Joe RC

Cool. ya keep me informed on how your new picco runs. I'm looking at getting either the nova rossi N528XR or the picco .28 P3. I'm gonna be racing mine so i'm gonna need a motor with a little more oomph. What kind of fuel do you run. I'm running o'donnell 20% right now in my mac star. Might be another one of my problems, i've heard o'donnell is the hardest fuel to tune with but once you get it dialed in it will have the most power. This is just what i heard not really sure. Also o'donnell doesn't have any castor oil in it which i don't like. I've heard good things about nitrotane so i think i'm gonna go buy a gallon and give it a try. Just curious to see what you run.

sirvancealott

At first, I ran O'Donnel 30%, then I switched to 20%. It actually seemed to get hotter on the 20%, but this could just be a conincidence. I've also suspected it was the lack of castor oil that might be an issue, but I use traxxas fuel in my traxxas stadium truck and the castor oil causes engine varnish deposits. So far, this has not effected the engine perforance though. I may have to just use the traxxas fuel in my Picco, since the local hobby shop has stopped carrying the O'Donnel fuel. He swears up and down that its great fuel, but I've heard some complaints about it from people online. Not really specific complaints, but everyone seems to have a bias against Traxxas as not being a racing company, but more of a newbie targeted mass market type of operation. I'm considering having some other fuel drop shipped, but that is very expensive. I'm sure the traxxas fuel will work if it comes down to it. It works great in my other engine.

sirvancealott

Hey Nitro Burner, you mentioned your engine could overheat if the low speed needle was too rich. Is that possible? I thought if you were rich, you were safe from engine overheating. I seem to recall someone else telling me the same thing a while back, so I'm very curious about this since its kind of counter-intutive. Thanks.

Foxy

I'm sure he just got it mixed up, there's no way a rich needle can cause overheating, unless the overheating is caused by another needle being too lean, such as the high speed. But I can absolutely assure you that a rich needle on it's own cannot be directly responsible for excessive heating of an engine.

sirvancealott

I totally agree. I just thought he might have meant that by setting the low speed needle rich you might set the high speed needle lean to keep it from bogging and low speed. Which, in turn might cause it to run too lean at high speed. Ultimately the cause would be the lean high speed needle, but the over-rich low speed needle might have made the high speed needle hard to set properly. I'm totally speculating here, I just wanted to hear what Nitro-burner had to say on that.

nitro _ burner

Think out-side the box people, if the LSN is too rich then you will lean out the HSN to compensate for it. and because the tuning is out of whack you will never get the needles set perfectly so its either going to run too lean or too rich.
This may be an "out there" theory, but you never know............

nye

I hope you havent purchased a new engine for your hyper st yet. The problem isnt the engine, its the fuel tank. I know this sounds crazy but if you reverse the fuel tank in the chassis it will run great once the engine is tuned.