Fire106

Looking for some help here guys.

My Revo has been sitting for about a month or two. When I put it away last I was having a problem. It would start up fine at first........then after about a 5 to 10 minutes of running.....it would stall at idle and become increasingly harder to start each time...until it would not start at all. I thought maybe it was just due to the cold weather and like i said....I have not run it in over a month. Well yesterday igot it all ready and took it out for a run.......I took some advice from the LHS and ran it a little richer and used a hotter plug due to the cold weather. Well it ran a little better but ended up with the same result.......the first 5 to 10 minutes it runs great........then stalls at idle and gets harder and harder to start. I'm thinking its a tuning problem and was going to return all the needles back to factory settings......but figured I would ask here first.

Any ideas??

One other thing. My EZ start is not working. Its turning the motor over but not heating the glow plug. It might be a short in the wire. My question If I remove the glow plug and hook it up to the wire while its out of the motor.......should it still glow when i hit the button on the EZ start??

pred192

try returning your needles to factory set and with the glow plug it should glow with the eazy start running, ive had problems with it glowing the plug so i took out the blue wire and now use a glow ignitor, it works alot better

Fire106

I returned the needles to factory settings and it ran a little better but same result. Each time I shut it down...it becomes harder and harder to start. Im going to try and seal the engine and carb tonight and see if that works. It pretty frustrating because it really runs well when it running.......its just getting it started after shutting it down.

I am using a glow igniter now as well but would much rather just use the EZ start.......less stuff to carry ya know.

Nighthawk z450

if you take the glowplug out, hook up the led wire to it, while Grounded it to the engine it should light up, but you have to hold it to the engine to complete that circiut, sounds like maybe "maybe" your glowplug needs replaced.
And how much fuel is through your engine?

Fire106

I am using a fresh glow plug and fresh fuel. If I use a glow igniter instead of connecting the blue wire...its starts right up the first time. For example.........If I were to go run the truck right now it would starts within 2 seconds........thats using a glow igniter. For the first few minutes it runs great and idles well. Temps around 200.........THEN after about 10 minutes...it stalls at idle........at that point it takes 10-15 seconds to start

Then after another few minutes of running.....it will stall at idle.......then take about 20-30 seconds to start.....and so on..and so on.

I have tried changing air filters......glow plugs.......fuel line.

Nighthawk z450

how much fuel is through the engine?

any the easy start, are both green lights lighting when your pushing the button with the blue wire on?

snoking16

sounds like its time for a new mill buddy...sorry to have to tell ya. when the engine heats up and expands its not getting the correct amount of pinch and ur loosing compresion. how many gallons are on the motor? take the motor apart and inspect the p/s and con rod to see if there is any serious wear.

A quick test....
with the piston and sleave out of the engine slide the piston up the sleeve. it should get hard to push once it gets about 1/8th inch from the top. if it is going flush with the top of the piston sleave its probably time for a new engine and if it just slides all the way through the sleave then its deffinatly time for a new motor.

Fire106

Yes both the motor and glow plug lights are on if I have the blue wire connected to the glow plug. The motor has less then a gallon of fuel through it

snoking16

how did the break in process go then?? any overheating? how many tanks did you do the break in on?

it still could be a worn p/s but with under a gallon through the motor it is unlikely although does happen every once in a while.

Nighthawk z450

if both lights are on thats saying there are no shorts anywhere, why it's not lighting i dont know?

got a good strong battery on there?

i you've only got that much fuel through it i wouldnt think it's shot,, engine was broke it right? not over heated-run lean?

Fire106

I did the break in exactly the way traxxas does it on the video. And I dont have any reason to think the motor is damaged due to over heating. It had always ran fine...then it sat for a few months...now its doing what I have described above. Im thinking about sealing the motor and carb but if it was an air leak wouldn't it run lean and over heat?

As far as the ez start battery....im using a 2400 Nimh...less than a year old and always worked fine. I had removed the ez start motor and wiring and put on a tiger drive but just reinstalled the ez start. I can try another battery to see if its just a battery power issue.

snoking16

there is not a leak...there are no symptoms of an air leak. try the tip i said earlier about pullin the piston and sleeve out to see where it starts to bind.

Fire106

I will pull the piston and sleeve out tonight and post some pics

snoking16

sounds good

Fire106

I just called the guy at my LHS and told him what the Revo is doing and he says thats exactly what would happen if the piston and sleeve are worn. Makes sense.....

When the engine is cool...no problems...but once it warms up and expands the problems start.

snoking16

yup...thats what i was saying. you should calltraxxas and tell them that the engine is toast after less then a gallon and u followed the break in process perfectly...they should help you out. i still want to see what the inside of the engine looks like.

Fire106

Im still planning on ripping it apart tonight. the guy I talked to says he doesnt have the p&s in stock.....there is another shop close by that opens in a few hours...hopefully the will have the parts

Fire106

Here are the pics.........there is some discolorization on the bottom of the piston...as well as some small scratches.

Soothsayerman

Looks kinda toasty for a basically new engine

george3.3

top of the piston should not have that colorization should it? does that mean it had been run lean. Alot! i have never had my internales have that color.

TheRealDeal

Fire106,,how is the pinch??(how far does the piston go up in the sleeve?)

tmaxx_man87

heres mine with around 2qts... looks totally diffrent... i think yours is toast...

j8to33

That looks alot better than my 3.3. The other night when I took it apart whell it looked black.

For tuneing watch theese videos
http://youtube.com/watch?v=wfAOq4jR2Y8
http://youtube.com/watch?v=QnYrdQ1UcqA

beer=food

Black running rich all the time, all claggy, and or dirt entering via air filter, that grey one but is from lean running AND lack of after run oil last time you used it, its had corrosion in the bottom end, then you have run it sucking small pieces of rust dust through the bore, the bore being oily from the fuel tends to stick all the dust or rust particles to it, like static on your lounge, then it just , basicly hones your piston, into an egg like fashion.As motor heats up, its doomed to stallage.
Anyways good luck on a new motor.

http://www.nitroreview.com/hintstips...ngTechTips.pdf

Fire106

Thanks for the info guys. I must have been running it pretty lean plus and it also looks to me like there were some particles in there also. Well lesson learned. I have been into RC for a little over a year but this will be my first engine rebuild. Some say I should just get a new engine but I don't mind the work at all..........its the best way to learn.

J8to33.......I actually watched that video series #23 to tear down the engine. And #24 covers reassembly.

I picked up a new piston sleeve and connecting rod last night on ebay and will hopefully have the parts in a few days. I plan on doing the breaking in according to traxxas video again.