justindu

Well let me start by saying I am brand new to the R/C and nitro scene. I picked up a CEN MT2 about a week ago, and had troubles with it immediately. The idle seemed a little high and it would go without hitting the accelerator (but I could still control it), then all of a sudden it just took off RUN AWAY!!

It ran smack into a fire extuinisher and flipped on its back. The engine was stils fully accelerated. So I pinched the gas line and it shutdown.

Now whenever I start it up, the idle is really high. Its like I have the accelerator pulled all the way back (and I am not even touching the radio). I tried playing with the idle screw, and I can get the idle to really low before it shuts off, yet when I release the break on the radio it just accelerates again!!

So I figured it was just a lemon cause CEN isn't as well known. I plan on sending it back to CEN to be checked out. So then I decided I would go get the much respected Savage 25. Went to the LHS today and dropped $550 total. I fired that up and guess what?? EXACT SAME PROBLEM!! @*&%!

I fire it up and the idle just keeps getting higher and higher and the wheels spin faster and faster while off the ground!! What's the deal? I checked the obvious things like:

- Throttle Trim on Radio is ok
- Carb isn't stuck open
- Linkage seems to be working fine


The only other thing I have heard of is an air leak. Yet my box had a red X on it, and I heard boxes with the red X have been fixed by HPI. So I took it back to the LHS and the guy there (supposedly) tweaked all the needles. I forgot my rotostart so I couldnt test it there.. but when I tried to start it at home it woudn't even start!

Any help or advice would grealty be appreciated!! Thanks Guys!

Justin

RCgangsta

I just got a savage 25 today. You dont need to touch the needles yet because there factory set to break in the engine(really rich). You also dont even need the radio for the first tank of gas. When i first started it up i noticed that the wheels were turning very fast but then, by hand closed the carb as much as the factory set idle screw whould allow and then it worked fine. The wheels will always turn a little, this is normal. The carb max should be 1/4 open. Take off the air filter and look.

justindu

Thanks

So the really high idle is normal?

RCgangsta

Well how high is it? Set it to 4 1/2 turns. You can put it back to 4 1/2 by screwing it in all the way(not to tight) and then unscrew it 4 1/2 turns.

RCgangsta

Doing that should slow down the idle.

green river rc

My Feedback: (2)

Don't forget about the throttle trim knob. Turn it down a bit and see what happens.

badboy2

My Feedback: (13)

u need to turn on radio even on idle thats why ur engines idling are high ....thats where the problem is ..and dont touch ur needles yet during break in ..when u finish ur 2nd or 3rd tank in idle then maybe id start touching them they usually recommend 1tank idle then oval run but i prefer to do like 3to5tanks in idle but thats just me

RCgangsta

3 to 5 Tanks? Thats a lot. I just run it for 1 tank then go in circles for 2 more.

badboy2

My Feedback: (13)

thats just me cuz i dont want to strain my engine right away just let it idle...well i guess it gives more life to the engine...u dont loose anything anyway except for 4tanks of run time ..for me its like warmin it up since the piston and the sleeve are brand new i let the engine get used to it first ..its ur choice anyway

RCgangsta

I whould have agreed with you until i read this thread.....[link=http://www.rcuniverse.com/forum/breaking_and_tuning/m_1371398/tm.htm]http://www.rcuniverse.com/forum/breaking_and_tuning/m_1371398/tm.htm[/link]

badboy2

My Feedback: (13)

well i guess it varies from experience i never had a bad engine except for my other bb21 that died cuz dirt got in the carb...ive had broken in 2 bb21,8port,picco26(my bros) fs18(terracrusher engine) and i never had problems and as i have said its ur choice and id still do it if ever i get a new engine

BLUEHAWK71

none

BLUEHAWK71

RE: New Savage 25 frustrated owner... (in reply to RCgangsta) Report This Post | (Post No. 1)


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Check the chrystal in the reciver on your truck i bought a new savage 25 and the reciver chrystal kept vibrating out i had to use a wad of rolled up papertowel and a piece of ductape to hold the reciver chrystal in.

Homebrewer

My Feedback: (8)

Don't blame the manufacturer for your inexperience in engine tuning and operation. Please find someone knowledge in this hobby and ask them not only for help in setting your car up but also a lesson of basic engine operation/tuning theory.

In2JeepN

Homebrewer is absolutely right...Nitro RC has come a LONG way from 10 years ago when I got started in it - mfr's have made it very easy to get started with all of the great RTR's out there, and usually have pretty detailed instructions that come with the kits. Most of the errors I have seen is because people are in too big of a hurry to go PLAY with their new toy that they dont slow down to fully read the break-in procedure in the manual - I dont mean the part of the manual about all the boring crap that no one cares about, although you should skim it.

Now onto the break-in procedure...everyone seems to have a different opinion on how to do, including all of the manufacturers....myself included. I stopped following the mfr's instructions a while ago after breaking in 2 identical motors 2 different ways - the mfr's way, and a way that was recommended by a knowledgable guy at my LHS. The motor that was broke in factory way lasted much less time before noticable power loss/poor idle/starting etc. than did the motor that I broke in using my buddies method - so here goes.

Place the truck so the wheels are off the ground, then richen the crap out of the engine until it barely makes the wheels spin at WOT....yes I know it may be a bugger to start like this, but it will - just jam the carb at WOT and leave the radio off. Run 5 tanks thru it like this (sounds like a lot but it only takes 5 min a tank or so when it's this rich - fuel should be coming out the exhaust in a heavy spray) heat cycling between tanks. Shouldnt get over 70-80 degrees or so, dependant on weather. Put the truck on the ground and lean out the HSN slowly (1/4 or so) a couple of times per tank while running back & forth across a parking lot (dont be afraid to use WOT - you dont have to do that 1/4 throttle, half throttle, thing - but dont let it wind out at high RPM for long either. After 5 or 6 tanks you should be somewhere near your final needle setting, and tune from there as you normally would...remember to keep an eye on your temps too.

Sorry guys, I know this has turned out to be a long post but I thought it was better to make the procedure that I use clear the first time than have everyone asking about it later. This is the best method I have found, and it still holds true - my Savage SS starts first pull almost every time and runs great, but my buddy has NEVER ending starting problems with his truck, and when he does get it running it runs much hotter than mine (sometimes upwards of 300) and both are about the same age etc. Just my 2 cents tho.