break in problems with 3.3
#1
Senior Member
Thread Starter
Join Date: Jun 2010
Location: ebbw vale, UNITED KINGDOM
Posts: 125
Likes: 0
Received 0 Likes
on
0 Posts
break in problems with 3.3
i bought a brand new trx 3.3 to replace the 2.5 in my t-maxx 2.5. breakin in now only on first tank following traxxas breakin vid to every word but the temp keeps reaching 290+, ive sealed the engine and carb and even bought a new tank and pipes for it incaase of an airleak but no difference, ive richended both needles to the point of it spitting nitro from the pipe and boggin down but temps are still high. i bought a 3.3 because i was fed up of this problem with my 2.5 but im still gettin problems im at the point of giving up now... please somebody have the answere.....
#3
Senior Member
Thread Starter
Join Date: Jun 2010
Location: ebbw vale, UNITED KINGDOM
Posts: 125
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
so you think i should carry on with the break in regardless of the temps, the shell is off so should be gettin plenty of air to cool. what is the heat cycle break in then??
#4
Member
Join Date: Jul 2010
Location: Diamondhead,
MS
Posts: 51
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
what glow plug are you using. i had the same problem and changed to a different one and dropped temps 30 degrees. This is the one i had 3232X. and i put a 3232 in it and ran fine.
#6
Senior Member
Thread Starter
Join Date: Jun 2010
Location: ebbw vale, UNITED KINGDOM
Posts: 125
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
im using a traxxas plug its the one that came with the new engine im not sure of what number it is , i will see if they got that black 3232 at my lhs mondaym, i hope that works im gettin fed up now spent too much on this allready... thanks for the info guys
#7
Senior Member
Thread Starter
Join Date: Jun 2010
Location: ebbw vale, UNITED KINGDOM
Posts: 125
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
tried running it again today, run for about 15 mins and temps reached 300 again, im thinkin av i got the sensor in the rite place, i got a lend of an onboard venom temp gauge and i have the sensor on the bottom fin of the cooling head and facing the petrol tank, thats a 90 degree angle from exhaust port as the instructions say, it doesnt seem like an air leak as the tunning responds to what i do with the needles, i just cant go any richer on the lsn or hsn because it just wont run, bogs down and is spitting nitro everywhere from exhaust. im gonna try that plug that was mentioned earlyr but other than that just dont know what to do..... does any1 have any advise
#8
RE: break in problems with 3.3
i have a buddy who had a similar prblem with a 2.5 and bought a brand new engine to replace it think the engine was shot.
low and behold he had the same problem with the new 2.5.
still with temps inthe 330 range
he gives me a call and we went through some diagnostic things and he had a tiny unseen crack in his header causing it to run lean no matter how rich he had it set.
so, he changed out the header and hasn't had that problem since.
check for air leaks everywhere not just the engine.
because these engines rely on a scavanging type exhaust they suck in exhaust as well as put out exhaust.
hope this helps
low and behold he had the same problem with the new 2.5.
still with temps inthe 330 range
he gives me a call and we went through some diagnostic things and he had a tiny unseen crack in his header causing it to run lean no matter how rich he had it set.
so, he changed out the header and hasn't had that problem since.
check for air leaks everywhere not just the engine.
because these engines rely on a scavanging type exhaust they suck in exhaust as well as put out exhaust.
hope this helps
#9
RE: break in problems with 3.3
I have 2 of the Venom temp sensors/failsafes in by junk box. I used them for just a couple tanks of fuel each and they've been in the parts box for about 2 years. I never had luck with them. I would verify the temp with a hand held temperature gauge to be sure the Venom gauge is reading correctly.
#10
Senior Member
Join Date: Apr 2010
Location: Happy Valley,
OR
Posts: 444
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
Take it to the LHS and they will get it tuned. Its probably just has tuning problem. BTW you shouldnt tune trx's until after break in.
#11
#12
Junior Member
Join Date: Sep 2009
Location: Ruckersville,
VA
Posts: 22
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
Interesting problem, I had this problem on a brand new HPI 5.9 it would run screaming lean even at idle with both needles wide open.
Fixed it by swapping the carburetor with an older (known good) one.
Probably had a crack in the carb body or a blocked intake orfice.
Some things that you mioght try:
If you have an inline fuel filter remove it, classic cause of air leaks !
Check all fuel lines for tiny cracks or tears, pinches etc. Even check muffler pressure lines.
Squirt fresh fuel through the carb fuel inlet with the needle valve open 4 turns, look into the carb air intake with the air filter off to see if you are getting a good stream of fuel. This also flushes the tiny fuel inlet holes.
A common problem with the 3.3 when new is the fuel "banjo" (black plastic ring where the fuel inlet nipple is) is loose. With the needle valve removed
tighten the brass fitting with a glow plug wrench (8mm). Don't over tighten! It is easy to strip the threads in the plastic carb body.
Another problem common to the 3.3 carburetor is that the needle valve plastic ring blocks the needle threads from ever reaching the
needle seat. When this happens you are turning the needle but it isn't moving in or out at all , just spinning. You have to push it down while turning it in (right) "Righty tighty lefty loosy" !
Fixed it by swapping the carburetor with an older (known good) one.
Probably had a crack in the carb body or a blocked intake orfice.
Some things that you mioght try:
If you have an inline fuel filter remove it, classic cause of air leaks !
Check all fuel lines for tiny cracks or tears, pinches etc. Even check muffler pressure lines.
Squirt fresh fuel through the carb fuel inlet with the needle valve open 4 turns, look into the carb air intake with the air filter off to see if you are getting a good stream of fuel. This also flushes the tiny fuel inlet holes.
A common problem with the 3.3 when new is the fuel "banjo" (black plastic ring where the fuel inlet nipple is) is loose. With the needle valve removed
tighten the brass fitting with a glow plug wrench (8mm). Don't over tighten! It is easy to strip the threads in the plastic carb body.
Another problem common to the 3.3 carburetor is that the needle valve plastic ring blocks the needle threads from ever reaching the
needle seat. When this happens you are turning the needle but it isn't moving in or out at all , just spinning. You have to push it down while turning it in (right) "Righty tighty lefty loosy" !
#14
RE: break in problems with 3.3
ORIGINAL: jord_trx2.5
what is the best plug to use to get lower engine temps
what is the best plug to use to get lower engine temps
#15
Join Date: Feb 2007
Location: , VA
Posts: 1,044
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
Same problem I had one time with a brand new 3.3, look for fuel slinging around the inside of the body due to the front seal leaking like crazy. Does it rev up at idle? I tried new carb, sealing everything, finially after traxxas gave me a new bearing for the front seal, and a new piston/sleeve due to the messed up breakin; everything was great. I bet its the front bearing/seal!
#17
Join Date: Feb 2007
Location: , VA
Posts: 1,044
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
ORIGINAL: nitrostam
your braking it in it does this just dont worry and break it in good if you have trouble after that you might look into it
your braking it in it does this just dont worry and break it in good if you have trouble after that you might look into it
#19
Senior Member
My Feedback: (1)
Join Date: May 2010
Location: midland, TX
Posts: 204
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
when i broke mine in it was gettting like 325 and i just kept on going and after breakin and tune it never gets over 260
ORIGINAL: Mspeed
The 3.3 should not run up to 300F while breaking in . I have broken in many 3.3's and this one had a front bearing bad seal during breakin and after breakin.
ORIGINAL: nitrostam
your braking it in it does this just dont worry and break it in good if you have trouble after that you might look into it
your braking it in it does this just dont worry and break it in good if you have trouble after that you might look into it
#20
Join Date: Feb 2007
Location: , VA
Posts: 1,044
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
ORIGINAL: nitrostam
when i broke mine in it was gettting like 325 and i just kept on going and after breakin and tune it never gets over 260
when i broke mine in it was gettting like 325 and i just kept on going and after breakin and tune it never gets over 260
ORIGINAL: Mspeed
The 3.3 should not run up to 300F while breaking in . I have broken in many 3.3's and this one had a front bearing bad seal during breakin and after breakin.
ORIGINAL: nitrostam
your braking it in it does this just dont worry and break it in good if you have trouble after that you might look into it
your braking it in it does this just dont worry and break it in good if you have trouble after that you might look into it
One time I had my throttle servo get stuck wide open on my revo, I finially managed to flip it over in a turn. When I ran over to shut it off while the wheels looked like pizza cutters and the engine is blazing, I saw the exhaust header spring snaped and fell off at that spot. After finially stoping the engine, I took a temp check for kicks and giggles, it was like 360 F. I tune for performance, smoke etc after break in, but 360F is alot for me.
My best 3.3 engine I broke in, ran best around 260 or so. Pulled wheelies all day long. Bottom line, if you richen up your needles completely and still have out of control temps, then i'd say something is wrong.
#21
Senior Member
Join Date: Jun 2010
Location: UC, TN
Posts: 136
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
Hay man just finish brakeing it in and go from there. If your engine is comfortable at high timps then leter have it. As long as its not showing simptoms of over heating or running leaning then it should be fine. hope i helped.
#22
Senior Member
Join Date: Oct 2008
Location: pefferlaw, ON, CANADA
Posts: 1,536
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
start with the simple things....like your temperature probe. i had a 3.3 that was indicating 425 on a venom probe ...but it was actually only 260.....id be checking with a quality temp gun before you go any further.
#23
Senior Member
Thread Starter
Join Date: Jun 2010
Location: ebbw vale, UNITED KINGDOM
Posts: 125
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
thanks for all the help guys, ive tried to reaseal engine now becase was paranoid that may still be an air leak but after reseal its still the same, it runs fine plenty of smoke and has a good constant idle but still same problem with the temp, after about 5 mins of running it reaches 320+. ive run a litre thro it now and jus keep stoping the engine wen it reaches 300. its a real pain in the ass, ive had nothing but problems
#24
My Feedback: (3)
Join Date: Aug 2004
Location: Northern, NJ
Posts: 1,099
Likes: 0
Received 0 Likes
on
0 Posts
RE: break in problems with 3.3
Two good ways to find air leaks is to clean the motor off so it's spotless and then run it somewhere clean like pavement and then check for oily residue creeping out of a problem area. There's also the spray method where you spray something (gotta look it up) around the carb and such to see if it affects the motor. Try leaning out the HSN and richening the LSN. What fuel and nitro percentage are you running? Is the fuel fresh? Take some photos of the engine from various angles after you run it and post them.