Leaking bearing on TRX3.3
09-08-2008, 01:28 AM
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Leaking bearing on TRX3.3
Hi guys
After having tuning and overheating issues too numerous to mention, I sealed up the carb and backplate for air leaks.
After checking the engine and carb for air leaks again, I have found one more - the bearing behind the flywheel that the crankshaft comes out of.
It leaks so much air that when I remove the engine from the model, and close the fuel inlet on the carb and the exhaust with my bare fingers, and simply blow into the carb air intake, I can clearly hear the air hissing out of the bearing.
Now I understand that a bearing is a moving part and unlikely to ever be 100% airtight, but if this engine is as high performance, high revving and high vacuum pressure as the manual implies, then surely an air leak of this magnitude is going to make reliable tuning all but impossible?
Any thoughts/advice would be welcome.
(By the way, I stripped the carb down to its last component, and there is no dirt or junk stuck in it. I have changed the glow plug. At least 3 different people (me being one of them) have had a go at tuning this car and they too could not get it right. I do believe my helpers knew what they were doing because they both had nitro cars (one Revo, one Savage) that were running very nicely. So I don't believe there is a tuning issue.)
I would like to hope, and believe, that this is the final issue with my engine before it actually starts to run properly!
After having tuning and overheating issues too numerous to mention, I sealed up the carb and backplate for air leaks.
After checking the engine and carb for air leaks again, I have found one more - the bearing behind the flywheel that the crankshaft comes out of.
It leaks so much air that when I remove the engine from the model, and close the fuel inlet on the carb and the exhaust with my bare fingers, and simply blow into the carb air intake, I can clearly hear the air hissing out of the bearing.
Now I understand that a bearing is a moving part and unlikely to ever be 100% airtight, but if this engine is as high performance, high revving and high vacuum pressure as the manual implies, then surely an air leak of this magnitude is going to make reliable tuning all but impossible?
Any thoughts/advice would be welcome.
(By the way, I stripped the carb down to its last component, and there is no dirt or junk stuck in it. I have changed the glow plug. At least 3 different people (me being one of them) have had a go at tuning this car and they too could not get it right. I do believe my helpers knew what they were doing because they both had nitro cars (one Revo, one Savage) that were running very nicely. So I don't believe there is a tuning issue.)
I would like to hope, and believe, that this is the final issue with my engine before it actually starts to run properly!
09-08-2008, 01:33 AM
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RE: Leaking bearing on TRX3.3
if you are running "traxxas top" fuel i hear that "eats" the front carb bearings, get a new one, and if your running traxxas top, switch to something else (unless thats all you can get out there), my friend ran traxxas top for a while and was loosing bearings left and right, and had the same airleak problems as you do, hope that helps
09-08-2008, 01:04 PM
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RE: Leaking bearing on TRX3.3
ORIGINAL: Rawlpower
Hi guys
After having tuning and overheating issues too numerous to mention, I sealed up the carb and backplate for air leaks.
After checking the engine and carb for air leaks again, I have found one more - the bearing behind the flywheel that the crankshaft comes out of.
It leaks so much air that when I remove the engine from the model, and close the fuel inlet on the carb and the exhaust with my bare fingers, and simply blow into the carb air intake, I can clearly hear the air hissing out of the bearing.
Now I understand that a bearing is a moving part and unlikely to ever be 100% airtight, but if this engine is as high performance, high revving and high vacuum pressure as the manual implies, then surely an air leak of this magnitude is going to make reliable tuning all but impossible?
Any thoughts/advice would be welcome.
(By the way, I stripped the carb down to its last component, and there is no dirt or junk stuck in it. I have changed the glow plug. At least 3 different people (me being one of them) have had a go at tuning this car and they too could not get it right. I do believe my helpers knew what they were doing because they both had nitro cars (one Revo, one Savage) that were running very nicely. So I don't believe there is a tuning issue.)
I would like to hope, and believe, that this is the final issue with my engine before it actually starts to run properly!
Hi guys
After having tuning and overheating issues too numerous to mention, I sealed up the carb and backplate for air leaks.
After checking the engine and carb for air leaks again, I have found one more - the bearing behind the flywheel that the crankshaft comes out of.
It leaks so much air that when I remove the engine from the model, and close the fuel inlet on the carb and the exhaust with my bare fingers, and simply blow into the carb air intake, I can clearly hear the air hissing out of the bearing.
Now I understand that a bearing is a moving part and unlikely to ever be 100% airtight, but if this engine is as high performance, high revving and high vacuum pressure as the manual implies, then surely an air leak of this magnitude is going to make reliable tuning all but impossible?
Any thoughts/advice would be welcome.
(By the way, I stripped the carb down to its last component, and there is no dirt or junk stuck in it. I have changed the glow plug. At least 3 different people (me being one of them) have had a go at tuning this car and they too could not get it right. I do believe my helpers knew what they were doing because they both had nitro cars (one Revo, one Savage) that were running very nicely. So I don't believe there is a tuning issue.)
I would like to hope, and believe, that this is the final issue with my engine before it actually starts to run properly!
09-08-2008, 11:16 PM
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RE: Leaking bearing on TRX3.3
After breaking in a fresh 3.3 I noticed a fair amount of leaking coming from the front bearing (ARO mostly). As my first 3.3 only lasted 1.5 gallons before the rear bearing let go, I was not going to take another chance. I replaced both bearings with some Acer ceramics and what a difference. They are super smooth and there is no leaking coming from the front bearing what-so-ever. Now only time will tell now they hold up. For $8 a bearing you can't go wrong.
09-09-2008, 01:35 AM
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RE: Leaking bearing on TRX3.3
Thanks for the comments guys
ajb1205 - How did you remove the rear bearing?
I managed to get the front bearing out by heating up the engine in the oven for 15 mins and then prying out the front bearing, but how on earth did you get the back bearing out?
How hot did you put your oven?
Thanks!
Johann
ajb1205 - How did you remove the rear bearing?
I managed to get the front bearing out by heating up the engine in the oven for 15 mins and then prying out the front bearing, but how on earth did you get the back bearing out?
How hot did you put your oven?
Thanks!
Johann
09-09-2008, 01:33 PM
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RE: Leaking bearing on TRX3.3
I read somewhere...mabey traxxas website, Somethinglike 400-450 deg. for 10-15 minutes. But dont quote me on that. I will try looking into it some more. The temp is rite...the time Im questionable on.
09-09-2008, 06:00 PM
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RE: Leaking bearing on TRX3.3
I have had the same issues with the newer 3.3's front bearing leaking bad enough that your tune is all over the place. I didnt see as many issues on the older 3.3's. The newer run with the new cooling head seem to really be having issues with bearings leaking.
09-09-2008, 09:07 PM
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RE: Leaking bearing on TRX3.3
ORIGINAL: Rawlpower
Thanks for the comments guys
ajb1205 - How did you remove the rear bearing?
I managed to get the front bearing out by heating up the engine in the oven for 15 mins and then prying out the front bearing, but how on earth did you get the back bearing out?
How hot did you put your oven?
Thanks!
Johann
Thanks for the comments guys
ajb1205 - How did you remove the rear bearing?
I managed to get the front bearing out by heating up the engine in the oven for 15 mins and then prying out the front bearing, but how on earth did you get the back bearing out?
How hot did you put your oven?
Thanks!
Johann
http://www.youtube.com/watch?v=TuzEco3EDUM
09-11-2008, 09:02 AM
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RE: Leaking bearing on TRX3.3
Thanks abj
I put it in the oven at 190C (about 380F) for 15 mins and gave it one tap on a wooden board.
The bearing leapt out of there like it was being chased by the cops.
I have a screwdriver on standby in case things got nasty, but the rear bearing literally dropped out exactly as you said it would without any resistance. The rear bearing was, incidentally, damaged. Some small metal bits were coming out of it (the piece that holds the bearings in place.) So my front bearing was leaking badly and my rear bearing was actually broken. No wonder my engine ran like crap.
I've ordered some replacement bearings from Boca Bearings.
Can't wait to put them in. At least I've learnt how to disassemble the engine now!
I put it in the oven at 190C (about 380F) for 15 mins and gave it one tap on a wooden board.
The bearing leapt out of there like it was being chased by the cops.
I have a screwdriver on standby in case things got nasty, but the rear bearing literally dropped out exactly as you said it would without any resistance. The rear bearing was, incidentally, damaged. Some small metal bits were coming out of it (the piece that holds the bearings in place.) So my front bearing was leaking badly and my rear bearing was actually broken. No wonder my engine ran like crap.
I've ordered some replacement bearings from Boca Bearings.
Can't wait to put them in. At least I've learnt how to disassemble the engine now!
09-11-2008, 10:13 AM
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RE: Leaking bearing on TRX3.3
ORIGINAL: Rawlpower
Thanks abj
I put it in the oven at 190C (about 380F) for 15 mins and gave it one tap on a wooden board.
The bearing leapt out of there like it was being chased by the cops.
I have a screwdriver on standby in case things got nasty, but the rear bearing literally dropped out exactly as you said it would without any resistance. The rear bearing was, incidentally, damaged. Some small metal bits were coming out of it (the piece that holds the bearings in place.) So my front bearing was leaking badly and my rear bearing was actually broken. No wonder my engine ran like crap.
I've ordered some replacement bearings from Boca Bearings.
Can't wait to put them in. At least I've learnt how to disassemble the engine now!
Thanks abj
I put it in the oven at 190C (about 380F) for 15 mins and gave it one tap on a wooden board.
The bearing leapt out of there like it was being chased by the cops.
I have a screwdriver on standby in case things got nasty, but the rear bearing literally dropped out exactly as you said it would without any resistance. The rear bearing was, incidentally, damaged. Some small metal bits were coming out of it (the piece that holds the bearings in place.) So my front bearing was leaking badly and my rear bearing was actually broken. No wonder my engine ran like crap.
I've ordered some replacement bearings from Boca Bearings.
Can't wait to put them in. At least I've learnt how to disassemble the engine now!
09-12-2008, 10:36 PM
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RE: Leaking bearing on TRX3.3
i just got done replacing mine it is siting in my lap as i type.my motor was overheating like crazy wouldn't idel at all would never hold a tune so i took my motor off and i found out i had a rip in the lsn(low speed neadle) boot and that thair was oil coming out of the front of my motor so i ordered the bearings on ebay for 26$ shipped.way better then geting it at the hobby store for $37.99. what i did is took off the head and put all the parts in sepret bags then i heated up the motor with a tourch so i could get the sleve out then took a tooth brush and pushed the sleve up and then it came out.took the piston off and pulled the crank and when i pulled the crank out the rear bearing was stuck on it so i beat it off and i had to heat the front of the motor up so i could get the front bearing out then hit it with a screw driver and a hammer and it came out.then i let it sit is some 2 cycle gas for about a day then scrubed it with a tooth brush to clean the hole motor in side out then let it sit for 1 hour then put the new bearings in and slid the crank in.i would use wd-40 when you put the motor back togeather it will make life a lot easer i found out the hard way then put the piston in then the sleve on then put it all back together and now it works fine.i haven't started it yet but i will tomarow and i wil let you know how it works.
09-13-2008, 03:48 AM
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RE: Leaking bearing on TRX3.3
Good stuff, let me know how it goes.
I like your idea of giving the engine a good clean on the inside - might as well - its all disassembled anyway!
I'm still waiting for my bearings :-)
I like your idea of giving the engine a good clean on the inside - might as well - its all disassembled anyway!
I'm still waiting for my bearings :-)
09-13-2008, 10:54 PM
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RE: Leaking bearing on TRX3.3
well i put it all back in my truck and it still wont run right it is geting hot and not holding a tune so tomarow i am going to seal up the hole motor with honda bond and go from thair
10-06-2008, 04:55 AM
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RE: Leaking bearing on TRX3.3
Well, after putting some Boca bearings in my engine, and sealing the backplate and carb with silicone - wow, what a difference!
The truck holds a tune, idles reliably (like it could idle for a minute whereas perviously 5 seconds was good), and doesn't overheat.
I am so chuffed!!
The truck holds a tune, idles reliably (like it could idle for a minute whereas perviously 5 seconds was good), and doesn't overheat.
I am so chuffed!!
10-06-2008, 10:33 AM
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RE: Leaking bearing on TRX3.3
ORIGINAL: Rawlpower
Well, after putting some Boca bearings in my engine, and sealing the backplate and carb with silicone - wow, what a difference!
The truck holds a tune, idles reliably (like it could idle for a minute whereas perviously 5 seconds was good), and doesn't overheat.
I am so chuffed!!
Well, after putting some Boca bearings in my engine, and sealing the backplate and carb with silicone - wow, what a difference!
The truck holds a tune, idles reliably (like it could idle for a minute whereas perviously 5 seconds was good), and doesn't overheat.
I am so chuffed!!
[8D] )
10-06-2008, 01:32 PM
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RE: Leaking bearing on TRX3.3
ORIGINAL: Rawlpower
Well, after putting some Boca bearings in my engine, and sealing the backplate and carb with silicone - wow, what a difference!
The truck holds a tune, idles reliably (like it could idle for a minute whereas perviously 5 seconds was good), and doesn't overheat.
I am so chuffed!!
Well, after putting some Boca bearings in my engine, and sealing the backplate and carb with silicone - wow, what a difference!
The truck holds a tune, idles reliably (like it could idle for a minute whereas perviously 5 seconds was good), and doesn't overheat.
I am so chuffed!!
Thats great to hear Johann!!! BUT, MY big question to you is, WHAT THE HECK DOES "CHUFFED" MEAN!?!?! [X(]
LoL, that's a new one for me! Glad to hear it is running good for you. I just recently got a 'very new' Traxxas Jato 3.3, and that thing SCREAMS!!!
For the weight of the truck, and the power or the engine, THIS thing HAULS @$$!!!! Just wanted to share my new vehicle with everyone!!
10-06-2008, 05:07 PM
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RE: Leaking bearing on TRX3.3
Looks pretty schweet there tmd!!! u definitely got one heck of a deal in that trade u made for this here jato man!!!! nice goin'!! [8D]
[8D]
10-07-2008, 04:12 PM
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RE: Leaking bearing on TRX3.3
ORIGINAL: Rawlpower
"Chuffed" = impressed / happy / elated !!
"Chuffed" = impressed / happy / elated !!
AHHH, I gotcha... I actually like that word! LoL... I'm Chuffed!! [8D]
