TRX 3.3 engine problems

[kevinF]

hey does anyone von here that has a traxxas 3.3 engine had any problems wiht it after just 2 gallons???

I know john (destroymyrevo15) does, and mine blows glow plugs just after like 1/4 tank.......some have the coil smushed in and others no damage except them not glowing.....

anyone else having problems??

[Ponch]

Are the bottoms of the plugs black or what color?

[Mr. Tune]

You're running it too lean prolly. If you blow it up real good after only 1/4 tank, I bet the plug started changing to a bluish color due to the excessive heat. I should know, I just did that on at the last race :o:

[kevinF]

Matt, no they look new.

tune, no it wasnt too lean, it was running at 230-260 and only a few plugs had the coil smashed in, but the rest were ok just didnt light

[rocco79]

add a shim....

[Ponch]

add a shim....

What will that do? Sorry, I just don't get the whole shimming the head thing yet. I thought you only had to do that for fuel % increase or decrease?

[rocco79]

it will knock the comperssion down... Make it easier to tune into the " sweet spot" and will save plugs...

Brian (MaxxGS) had a 2.5r with a very similar problem... He added a shim and the engine ran well

[kevinF]

yeah rocco i also added a head shim

[Traxxas_Junkee]

He already did that, and it is still blowing the plugs.

[Ponch]

Put another one in then and see what happens.

[rocco79]

Well as the tree said to the lumberjack..." im stumped!"



What kinda plugs???

[Ponch]

Wow....You ran outta good stuff huh?

[rocco79]

Its a Flanders saying! LOL!!! (simpsons)

[kevinF]

well i have run the stock traxxas glow plugs, the heavy duty traxxas plugs and then recently mc59......ever since I change my exhaust header to o.s. I have had this problem, I then went out today and bought a stock exhaust header and the problem continues

[Mr. Tune]

Richen it up more. Does it have good smoke? Ignore those temps, because something as simple as dirt on the sensor and throw of your temp gun's readings. Put a drop of water on the head and see how long it takes to sizzle away.

[Traxxas_Junkee]

When we were at the track last night it was really smoky, I think it was too rich.

[Czech-it-Out Graphics]

If the plugs are still getting smashed in I would have to say the deck height is still too low, the only thing that causes that is too much compression, what does the piston top look like, is it pitted at all? should have a nice brownish burnt look on top, and by burnt i dont mean scorched I mean like a burnt oil look

[kevinF]

it has great smoke, and thats what i thought mike, thats why i added a head shim.....the head shim solved the smushing the coils in, but now that plugs just dont last.

and you know how you can sometimes get burnt fuel on your piston and it looks like gray dirt??

well the top of the piston is now kinda grey.

im sending it to traxxas tommorow so hopefully they can figure it out and fix it for free

[Czech-it-Out Graphics]

shouldnt look grey, that woudl be lean, should look black, ur prolly doin the best thing sending it in

[kevinF]

yeah but it has only been at 300 a couple times and only for a few seconds and when it was at that temp it had planty of smoke.

ever since i put that header on it screwed up my motor

[Tex]

Plenty of people run the OS header with the traxxas motors with success, that's not what screwed up your motor.

"Grey dirt" on top of the piston is you running too lean, the proof is there.

To note the things I've seen wrong with the 3.3's, they are, snapped connecting rods probably due to noobs, and main engine bearing letting go prematurely

[kevinF]

well but how can it be too lean if there is plenty of smoke???

also my one wat bearing broke on me....wonder if that has anything to do with it??

and I didnt mean there was grey dirt on top of the piston but that the COLOR of grey dirt was on the piston

[Traxxas_Junkee]

Kevin take the head off and take a pic of it and post it.

[kevinF]

ahhh..........damnti i think i already sent it out

let me check

[kevinF]