bad 3.3

[chowmanstoys]

i got a used 3.3 and it wont run.
could it be a bad sleeve piston(worn out)
or what?
should i get new glow plug?
should motor be sealed?
how easy should it be to turn by hand?

 

[joshman1204]

Start by setting all needles back to stock and replacing the glow plug and then see if it will start.

Once you get it to start refer to the tuning flowchart on this site to get a tune on it.

 

[Bkyd Basher]

If u have the know how, i would pull it apart and examine everything real well,if i didnt find anything noticable i would seal it up real good, take the carb apart and clean it and blow it out with an air compressor. Put it all back together and set it to factory settings. Put in a new glow plug that u know works and go from there.It should turn smooth and easy until it gets right up to top dead center than stiffen up pretty good until it starts to head back down.

 

[chowmanstoys]

will a 3.3 with bad compresstion still run?

 

[Bkyd Basher]

well depends how bad i guess. Usually if there on there way out they will run good until they get to full running temp, then they will start real hard or not at all till they cool back down. The one big thing i have notic
ed also when they get whooped is they will leak real bad between the front crank bearings inner race and the crank. I took a piece of new fuel line,with the clutch and flywheel off. I would hook the line to the fuel inlet on the carb and plug the rest with my fingers and put some soapy water around that bearing with a small paint brush. Blow into it and bubbles start to form. You can also pull the sleeve and piston and rod out and see how tite it fits when it gets to top dead center. Should have alot of tightness b4 i reaches the top of the sleeve. Hope this helps. I am not an expert but i have been playing with a bunch of 3.3s lately and this is what i have found.

 

[chowmanstoys]

i dont know what else to try
did new plug, checked everything over,
the motro just wont start, turns over good.
settinge are factory, fresh batteries,
its almost lke the fuel is not burning,right?

 

[Racer 1966]

When turning it over by hand with the plug in,does it get tight at the top of the stoke then roll on over with slight "pop"and get easy again? An engine without compression will not run.

 

[pugs2300]

i hate 3.3's...nothing but trouble...every other nitro engine i have had as been a pleasant experience...3.3's are nothing but trouble...

 

[chowmanstoys]

When turning it over by hand with the plug in,does it get tight at the top of the stoke then roll on over with slight "pop"and get easy again? An engine without compression will not run.

ya its not very tight at the top, not much of a pop.
will not fire.... thinking its done...

 

[chowmanstoys]

crank shafts???

whats the diff between 2.5 and 3.3 shafts???/ pics would be great

 

[Jayjay1985]

i hate 3.3's...nothing but trouble...every other nitro engine i have had as been a pleasant experience...3.3's are nothing but trouble...

My 3.3 in my slayer is absolutely the best engine I have ever owned not a single problem and holds a great tune

 

[Bkyd Basher]

Well i dont have pics but the 2.5 shafts have like 4 bigger square splines and the 3.3 shafts have multiple smaller rounded splines.Just go on ebay and search for Traxxas 4907 3.3 Tmaxx Center Shafts.

 

[Old2.5]

Hated my 3.3 held a tune great don't get me wrong but after 3 gallons there done start running like crap and lose compression

 

[TRXaddict]

my friend had an issue with his t maxx where he could barley get it running and only could get it running if its almost wide open... i took the motor out, cleaned it up and then sealed it with some RTV around the crank back plate, the carb, and then tightened the head as eavenly as possible and then spent awhile on tuning and it ran better than before...

whats your altitude ?

 

[BlackedOut08r1]

sounds like its just out of compression and needs a rebuild