Pn2K7

Hey guys,

I just recently but my first nitro truck to see if I like it and I am having a horrible experience. Granted I bought a no-name brand because it was cheap, I wanted to make sure I liked it before I upgraded to something like a XXX-nt AD2. When it works I love the power, smell of exhaust and speed. Sadly it works five minutes and then I spend 45 minutes trying to get it to run again. It starts up fine and I will run it a couple of minutes and do the bioling water test on the engine and make adjustments. Then after five minutes or so the sound of the engine seems to idle fast and I have to turn my throttle trim all the way down or the truck will move on its own. After about five minutes the truck will stall when I try to accelerate it. I will check the glow plug to make sure it is tight, etc, etc. I can usually get it to start but the idle sounds way to fast and the truck will die after a minute or when I accelerate, sometimes the truck just takes off from the idle being so high. I have tried richening and leaning the high adjust drastically just to see if the engine sound changes, to be honest it always sounds high idle after any adjustments. The only difference is if I adjust to much the engine doesn't start at all. I go through this routine for 45 minutes before stopping because I know I will get mad and hulk out. I will clean the truck and cool down emotionally for a day and go through the same routine. The only time the truck worked for more then five minutes was during the breakin. I have attached a link below for the truck I bought, I know you will probably tell me "what the hell were you thinking". The engine only has a high speed adjustment and idle adjustment, no low speed. I know you have to tune nitros but this truck does not stay tuned for more then five minutes before it becomes a whole different monster. Is nitro really this difficult? If I do upgrade to a AD2 with a trinity engine and some point will it be just as difficult? If so, I will never be able to race. The link to the truck is below any advice will be greatly appreciated.

http://www.redcatracing.com/itemdeta...partno=TSUNAMI

FalloutMan

Ok, I checked the link, and, from one of hte pics, it seems you have a low speed needle (many people call it a lsn, adn high speed is hsn) http://www.redcatracing.com/picsgallery/tsunami6.jpg At the black thing where your throttle servo arm connects to the carb and turns it, there should be a screw in the middle. if there is, turn it out 1/8th turn until your idle and accelloration probs go away. And, to answer your question, yes and no. For me in washington, since the weather changes drasticly from day to day, tuning is something i do almost every day until spring comes and the weather mellows out. Itll take time to learn all the stuff.

tgwolfwood1981

it may also be something as simple as a glow plug going out.

dannthenitroman

I think he just needs to learn to tune. yes you really do have to tune them.

GRANT ED

Agreed.
Nitro engines can be frustrating to start with if you have no one there to help you, but if you read and learn as much as you can it does become easy. With a bit more experience your problems running nitro will go away and you'll wonder what the drama is.
As Falloutman said the problem your having sounds like the LSN is set too lean. Turn it out 1/8th of a turn at a time untill the idle speed and acceleration is normal. A symptom of having the LSN too lean is a high idle speed.

125cchyperman

Yep that looks like a LSN, just richen that up a little and you should be ok. Once you get more experience it wont be that hard, yes every nitro need's to be tuned but it's not all that hard once you get a hang of it. Now some engines may need more attention tuning wise then others as some engine are tempermental. But it just sounds like if you richen the LSN a little you should have your problem fixed and be having fun, the worst thing you can do when your new to this hobby especially with nitro's is to glance through the manual and not really pay attention or ready it. Read the manual every bit of it, then you will know what your truck has and doesnt have.

But I agree with Dann and GRANT ED just sounds like a tuning issue.

RCtruckRacer

First, unless the brake set up is totally alien to other r/c cars, you should not be using your throttle trim to adjust the idle. This is your first problem. If you have the throttle trim set out to increase the idle, every time you hit the brakes the throttle is closing and probably helping to cause the engine to die. There should be an idle stop screw on the carb. Put it at factory settings - usually that means a 1 or 2 mm opening in the carb venturi. Make sure the throttle trim is set so that the carb does not move (close) when you hit the brakes. Try this:


Why do we ‘tune’ our engines? How is it done? This guide assumes that you are familiar with all of the parts of your R/C's engine. If you are unsure what a Low Speed Needle (LSN), High Speed Needle (HSN), idle screw etc are, please refer to the manual (RTFM).
Tuning a nitro/methane 2 stroke engine literally means adjusting the air/fuel mixture inside the chamber. This is done by means of adjusting the amount of fuel that is allowed to flow into the carburetor via needles which can be opened and closed. Most of us know that there are a wide variety of factors that affect that air/fuel mixture in the chamber other than just adjusting the needles. Because of this an engine may have to be tuned several times in the same day for optimum performance. Not maintaining an optimum air/fuel ratio can result in poor performance, or even engine failure!

There is a point, in every engine, at which air/fuel mixture will allow the engine to obtain its maximum HP and RPM’s. Tuning your engine to that point can be dangerous, as the mixture is somewhat lacking in the lubricants necessary to give maximum protection to the engine. Therefore, most people will want to run slightly rich (more fuel in the mixture) of that point. This is referred to as the ‘Sweet Spot.’ Some racers will run at pure max potential, but they also don’t usually care if the engine only lasts a gallon… Running at those settings can be very dangerous because being too lean is just a very slight adjustment away.

And running lean is the real engine killer, not temperature. With proper lubrication, the internal components of an R/C engine can easily withstand temperatures of 300F, maybe even more. The thing is, these engines are designed to operate at temperatures around 210 – 270 F. While there is the possibility you will encounter an engine and conditions that dictate the temperature at proper tune is over 300, it will be a rare occurrence. What that boils down to is that there is a good possibility that there is a problem if your engine reaches too high of a temperature. That is why it’s a good idea to monitor the engine temperature, but not use it as a guide for adjusting the air/fuel mixture in the engine.

So, how do you get to that ‘Sweet Spot?’
1) Start out with rich settings. If you are unsure how to go about this, an easy way is to start with stock needle settings. This includes the idle screw - make sure it is set at factory settings, usually a 1 or 2 mm opening for the idle stop. The factories always set engines rich for break ins.
2) next, warm up the engine. Try not to hammer the throttle too much while its still bone cold, but slowly work your way up to a couple WOT runs.
3) Now that the engine is warmed up (1/2 tank is good), do a couple WOT runs of about 50-100ft in front of you and pay attention to the pitch of your engine. The higher the pitch, the more RPM's its doing.
4) Now lean out the HSN by 1 hour increments (30 degrees, 1/12 of a full circle etc) and continue to do some WOT runs in front of you. The engine's max RPM's should continue to go up each and every time you lean out the HSN by those 1 hour changes. If it doesn't, you have reached the top end and need to richen by an hour. Make sure that you do not continue to lean out the HSN after max RPM's have been reached. You will damage the engine.

Congratulations, you just found the sweet spot. Now, if you notice that the car/truck bogs a bit at take off, lean out the LSN (again 1 hr increments) until it will take off at the touch of the trigger.
And you're done. At this point I like to temp the engine to get a baseline reading for the day.

This is a simple and fool proof method of tuning that everyone can do. Regardless of your experience.

dannthenitroman

5 points for that. that was really nice

Pn2K7

Thanks, your information was awesome. I was disppointed with the instructions that came with the truck, they did not explain the needles and idle in any detail just "turn this direction" if engine does this and this is suppose to be a "great for beginners car." The carb is closing up with the breaks so I will look at the servo tension and connections before my next run.


Phil

Pn2K7

Thanks for all the great information guys, this helps a lot. I appreciate all the responses usually when I ask a question in a forum of any sort, I recieve responses of two guys arguing with each other and my question is never addressed. Is $297 for XXX-nt AD2 brand new and $169.00 for Trinity Drake platinum standard engine new, a good price for each?

RCtruckRacer

Both are very good prices, especially if you do not have to pay shipping. If you decide to go with the AD2, and need some setup help, feel free to give me a PM. I have a few hot tips I can give you.

FalloutMan

so, did you get your idle and accelerate issues worked out?

Pn2K7

I will work on the truck tomorrow it is my day off,plus I left GP igniter at my friends house.


P.

dannthenitroman

if the brakes close the carbie, turn the idle screw clockwise until this stops happening. this is wrong. if the idles now too high, use the throttle trim to back off the servo (so the spring has tension on it) then back out the idle screw until it is at an acceptable level.

Pn2K7

I thought those were great prices, still kicking around the idea of getting one, I like to build stuff and a kit like that looks like a lot of fun, I already downloaded the instruction booklet. I emailed Adam Drake for his advice on the engine, I guess I should not have been surprised when he said to get the "Adam Drake Trinity engine". Most the engines in my budget have rally low Horsepower and I know that would come into play while racing. Is the pipe that comes with the AD2 worth keeping or is that something that you would upgrade for racing, and if yes, what is a good brand? I have seen some great prices for Trinity pipes on Ebay.



P.

squeaky penguin

Well there's your problem!! I wasted some of my money too on those Redcat pieces of crap before I finaly bought a name brand car. Also, have you messed with you idle screw on your engine that much?

RCtruckRacer

The AD2 pipe is the best. I see it on lots of 1/10 gas trucks besides the AD2.

IMO the best way to solve your throttle linkage issue is to:

Take the horn off the servo. Put all of your radio adjustments to zero (stock) - end point (to 100%) if you have it, trim etc.

Turn the truck on. The servo will center itself when it powers up. Now, put the horn back on so that the linkage has pushed the carb closed as much as the idle screw will allow. You want your idle to be at the full neutral position of the radio and servo. Tighten everything back up. Now, if you have some kind of issue where it take a lot of servo movement to open up the throttle, or hit the brakes, then you need to adjust those linkages accordingly. Always set your linkages so that everything works as perfectly as possible from all the zero settings on the radio. This will give you the greatest amount of adjustment possible from the radio.

IMO of course.

avg_joe

My first reaction to the initial post was---Air leak.
Especially when you said it was a 'no-name'. I have heard bad things and I have heard people defending them.
It seems that the more experienced hobbyist has better luck with them, as they can put some of the finishing touches on an otherwise rough final product. Just pure un-based assumptions on my part, as I haven't even seen one in person.

Double check that there are no air leaks where the carb mounts to the engine.(the best way to 'check' is to remove it, clean it, and seal it with a small bead of RTV sensor safe gasket maker)
Check the back-plate screws to make sure they are tight.
Check the cooling head screws.
Make sure the tank lid seals tightly, and your fuel lines don't have any holes in them.

Good luck! Stick with it. There is a steep learning curve when starting, but it gets better fast.

Pn2K7

I hope I have to put all the wonderful wisdom I recieved into use today, so many errands to do. I am still kicking around the idea on the AD2 perhaps premature I placed a bid on a pipe via ebay. I lost the auction but recieved a second chance offer for a Off Road Inline Pipe model 8132 for $39.00 with shipping or should I pay $52.00 for .12 Drake Off Road Inline Pipe model TRI42011? The engine I will be getting more then likely would be the Trinity Drake Platinum. I am not sure if I should pay the extra 12 dollars and get the Drake pipe or if the regular Trinity inline would be just as good.


Phil

dannthenitroman

probably just as much smile factor, youll only get to test one and they will both be good so how would you ever know you got the worse one? you wouldt, get the cheap one.

rclynx

Hey squeaky I own a Hobby shop and I don't even slam products for any reason. I don't recommend a lot of products and I still give my opinion without being nasty about it. Redcat has good products and bad products just like everyone else does in the industry. The most problems I find with any of them is some people are to stupid to even own a RC car and don't know how to fix them. Its not the fault of any of the cars or trucks its the idiot that doesn't know how to fix it. This is a hobby sport! So if you really don't have anything to say in a nice way why don't you post somewhere else. Every dog has his day

sapper ion

uhh, nevermind, i screwed up this post, Nothing here just keep reading on

Pn2K7

I maybe a true beginner when it comes to nitro but I don't think I am stupid.

sapper ion

I said the same thing before i realised he was talking about someone else, He wasn't bashing you, I think he understands that you were just looking for help

rclynx

Pn2K7 didn't have anything in the world to do with you m8 / if you can't get it straight PM me and I will help you out. I do this for a living [:-]