 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
| HomeDiscussion Groups General ModelsRailroadsRocketsRadio Controlled Air ModelsHelicoptersLand ModelsWater ModelsModelGeeks.com Contact UsLink To UsSearch & Site Map |
Model Forum / Radio Controlled / Land Models / June 2006new to hobby and having a problem
I have build and messed around with a few electrics, but that was almost 10 years ago. This past weekend, I bought an HPI RTR Nitro RS4 3 Evo, and have been having a problem. The manual says to break it in by basically letting it idle through two tanks of gas. I did that, and it worked OK. It would stall sometimes, but it starts right up now. The second step was to run the car at low to mid-range speeds through 4-6 tanks of gas. This is where the problem starts. The car does not move at all as I pull the trigger. Once I reach about mid throttle, the engine cuts out. I now wish I hadn't bought a RTR so that I would know what I was looking at it having put it together. It appears to be running very rich as it spits fuel out of the exhaust. I have not touched any of the factory settings, and have just let the car idle as I said. There seem to be a couple of problems here. I am a little disappointed as the thing just came out of the box, doesn't seem to be working properly, and the store won't take it back. Before I bought it, they told me it was returnable if it didn't work, but now they have changed their story. This, however, is a different matter. Has anyone experienced this or have any ideas on how to get it running? > I have build and messed around with a few electrics, but that was > almost 10 years ago. This past weekend, I bought an HPI RTR Nitro RS4 [quoted text clipped - 21 lines] > > Has anyone experienced this or have any ideas on how to get it running? Don't give up. Many times a RTR car/truck will need the carb adjusted. Carbs in nitro vehicles are very sensitive to humidity, elevation, heat, etc. I would find the low speed needle and lean it up a hair, like 1/16th a turn. Try that. If it still stalls before the clutch engages, another 1/16th turn towards the lean direction. Keep doing this until you can keep the motor running enough to engage the clutch and drive the car. There should be smoke coming out but not large amounts of fuel-that means too rich. >> I have build and messed around with a few electrics, but that was >> almost 10 years ago. This past weekend, I bought an HPI RTR Nitro RS4 [quoted text clipped - 30 lines] > and drive the car. There should be smoke coming out but not large > amounts of fuel-that means too rich. Ignore this advice! Don't touch the low-speed needle (LSN). If your car idled fine thru a few tanks of gas the LSN setting is ok for now. Your problem is with the high-speed needle (HSN). The carb "jumps" from LSN to HSN about 1/8-1/4 throttle, so if it's crapping out mid throttle this is a problem with the HSN and NOT the LSN. This is a very common "issue" with any nitro motor that isn't properly tuned. They are shipped super rich for break-in and usually do need to be leaned out a bit to run reliably. Basically the engine is running so rich it cannot produce enough power to engage the clutch and then stalls out due to flooding. Turn the HSN 1/8 turn clockwise (lean) and see if you can get her moving. If she still just sputters and dies try another 1/8 turn clockwise on the HSN. Continue leaning the HSN until you can keep her running and piddle around the driveway. DO NOT overlean the engine at this point. The goal here is to keep it running at slow speeds as rich as possible without stalling it. You'll continue leaning the HSN for performance after the 4-6 tanks. Bear in mind: 1) There is nothing wrong with your car. You're just a newb and don't know how to tune a nitro engine yet. Don't give up dude! Nitros are cantankerous little biyatches until you figure out the basics of tuning. 2) The car will still be very sluggish for the 4-6 break-in tanks. This is NORMAL! You won't get decent performance until after it's broke in and has been performance tuned. 3) Don't touch the LSN until AFTER the HSN has been tuned for peak performance. HSN is like a master fuel valve for the carb, and HSN settings affect the amount of fuel that flows to the LSN, so if you lean the LSN now, and then lean the HSN later for performance, you'll end up with an overly lean LSN setting and likely overheat the engine. 4) HSN first, LSN second, idle-set screw last. HTH, Doc >>> I have build and messed around with a few electrics, but that was >>> almost 10 years ago. This past weekend, I bought an HPI RTR Nitro RS4 [quoted text clipped - 65 lines] > > HTH, Ditto everything he jsut said :-) DO NOT TOUCH THE LOW SPEED NEEDLE.  SignatureDan "Doc" wrote: > >> I have build and messed around with a few electrics, but that was > >> almost 10 years ago. This past weekend, I bought an HPI RTR Nitro RS4 [quoted text clipped - 67 lines] > > Doc My bad, I meant high speed needle. Woops........ That did it. Thanks a lot guys. It is now moving around...just in time for it to be raining for the next week. I guess I will have to wait until next week to break it in and finally get to run it. Thanks again! > That did it. Thanks a lot guys. It is now moving around...just in > time for it to be raining for the next week. I guess I will have to > wait until next week to break it in and finally get to run it. Thanks > again! You're very welcome! Another hint: HOT plugs work best for breaking in a motor. I use OS A3's for break-in as they'll keep a stinking rich mixture burning. And ALWAYS throw away the plug you used for break-in after break-in is completed, even if it hasn't died yet (and it will!). Doc The weather cleared yesterday, so I ran it at medium/low speeds through 4 tanks like the manual said (it says 4-6). I will probably go ahead and do this for two more tanks to be thorough. Sometimes it runs along pretty well, but other times it will slow down and then not move, and I have to ease on the gas to get it moving or it will cut out. It's touch and go. Is this something that will clear up when I tune it up after break-in? > The weather cleared yesterday, so I ran it at medium/low speeds through > 4 tanks like the manual said (it says 4-6). I will probably go ahead [quoted text clipped - 4 lines] > will cut out. It's touch and go. Is this something that will clear up > when I tune it up after break-in? Yeah, it should clear up as soon as you start leaning the HSN for performance. It's still running slobbering rich and as such will run like bunk. Now that break-in is almost complete, start leaning the HSN for performance, ssssllllloooowwwllllyyy! Lean it in 1/8 turn increments until you get decent top end speed. Don't beat the sh.t out of it at this point, as you want to gradually lean it out and gradually bring the motor up to proper operating temp. It might take you another 2-3 tanks to get the HSN setting right. You want decent top-end performance, a nice smoke trail at WOT and temps between 220-280* or so. When you get all three the HSN is set correctly. Doc >> The weather cleared yesterday, so I ran it at medium/low speeds through >> 4 tanks like the manual said (it says 4-6). I will probably go ahead [quoted text clipped - 16 lines] > top-end performance, a nice smoke trail at WOT and temps between 220-280* > or so. When you get all three the HSN is set correctly. And when you've been in the game for a bit, you'll be able to tune it to sound and 'feel' :-) Temp gus? Pah ;) SignatureDan "Doc" wrote: > >> I have build and messed around with a few electrics, but that was > >> almost 10 years ago. This past weekend, I bought an HPI RTR Nitro RS4 [quoted text clipped - 67 lines] > > Doc I have a Kyosho Stadium Force RTR with similar issues. It has needle valve, air fuel mixture, and idle tuning. Is the air fuel mixture the same as the HSN? Thanx. > "Doc" wrote: >> >> I have build and messed around with a few electrics, but that was [quoted text clipped - 88 lines] > > Thanx. HSN is usually located where the fuel hose connects to the carb. It's usually a bigger screw located at the top of a brass barrel. LSN is usually on the side of the carb. Idle speed screw can be located pretty much anywhere on the carb. Doc |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.