R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro Off-Road

Reply
 
Thread Tools Search this Thread
Old 09-03-2009, 06:57 PM   #1
Tech Rookie
 
Join Date: Dec 2007
Posts: 13
Default Possible air leak?

My rc truck (Savage X SS) has been giving me hell with tuning. I suspected an air leak, but hadn't got around to checking.
Well today as I was trying to start the motor, I could hear air coming from the back of the engine. I take the engine off the chassis and using the method by Squirrelod, I check the backplate and exhaust manifold for leaks. No air coming out.
My next thought was an issue with the sleeve/piston. Maybe when it's warmed up there's a small air leak somewhere but not while it's cold.
Do I need to buy any new gaskets for anything before I take this apart or can I just put it right back together if there's no issue ?
Would I be able to tell if there was an issue with the sleeve while it's cold, seeing as how the problem comes up while it's hot ?
Jeimuzu is offline   Reply With Quote
Old 09-03-2009, 07:13 PM   #2
Tech Elite
 
jpalessi's Avatar
R/C Tech Elite Subscriber
 
Join Date: Feb 2008
Location: SoCal
Posts: 4,747
Trader Rating: 55 (100%+)
Send a message via AIM to jpalessi Send a message via Skype™ to jpalessi
Default

Quote:
Originally Posted by Jeimuzu View Post
My rc truck (Savage X SS) has been giving me hell with tuning. I suspected an air leak, but hadn't got around to checking.
Well today as I was trying to start the motor, I could hear air coming from the back of the engine. I take the engine off the chassis and using the method by Squirrelod, I check the backplate and exhaust manifold for leaks. No air coming out.
My next thought was an issue with the sleeve/piston. Maybe when it's warmed up there's a small air leak somewhere but not while it's cold.
Do I need to buy any new gaskets for anything before I take this apart or can I just put it right back together if there's no issue ?
Would I be able to tell if there was an issue with the sleeve while it's cold, seeing as how the problem comes up while it's hot ?
it's probably the carb,,, they are known to leak and have problems.. look to see if it's wet around the carb..
__________________
Joe Alessi
www.Lucky7RC.com
jpalessi is offline   Reply With Quote
Old 09-03-2009, 09:38 PM   #3
Tech Rookie
 
Join Date: Dec 2007
Posts: 13
Default

And if it's not ? What are some other things it could be ? I'd rather not have to keep coming back after each little thing I check :/
Jeimuzu is offline   Reply With Quote
Old 09-05-2009, 02:07 PM   #4
Tech Rookie
 
Join Date: Dec 2007
Posts: 13
Default

bump
Jeimuzu is offline   Reply With Quote
Old 09-05-2009, 05:54 PM   #5
Tech Champion
 
jmackani's Avatar
 
Join Date: May 2009
Location: Shippensburg
Posts: 5,596
Trader Rating: 14 (100%+)
Default

Double check the exhaust manifold rubber gasket and make sure the glow plug is tight. You will see fuel bubbles around the glow plug if it is not tight.
jmackani is offline   Reply With Quote
Old 09-05-2009, 09:36 PM   #6
Tech Master
 
offr0aden's Avatar
 
Join Date: Mar 2006
Location: An Offroad track near you!!
Posts: 1,097
Trader Rating: 6 (100%+)
Default

First .. is the engine sealed?

Second .. was the engine running fine and then all of a sudden it started to go away?

Third ... If its a fairly new engine... have you had it apart and sealed it before break in? And if its new how much run time / amount of fuel have you run through it.

Forth ... if the above all check out fine or you reseal the engine while you have it out. check the carb low side boot. Its the boot your throttle linkage connects to. This is a common place for air leaks. If there is a crack or the boot is loose, it will suck air. If it loose at all cold it will be worse when its hot. Some use a zit tie and tie the boot where it mounts to the carb. That works in most cases, and will get you bye while you order a new one and then replace it. Some carb have loose boots by design, and in that case get another boot that fits tighter, or use the zip tie method on the new boot.

There are no gaskets that come with the engine, only shims on the head. And unless you have a lot of moisture under the cooling head, and or you head screws are loose, you shouldn't have to reseal it or replace the shims.
__________________
- Team -
"High Speed and Clean"
offr0aden is offline   Reply With Quote
Old 09-06-2009, 05:00 PM   #7
Tech Rookie
 
Join Date: Dec 2007
Posts: 13
Default

First: No it's not sealed. I plan on doing it tonight or tomorrow.

Second: Not really. I've been having trouble getting it tuned since I started driving it.

Third: First nitro engine ever, and it's not been sealed. I've got about 2 tanks past break-in, all trying to tune it.

I'll seal some stuff up and post the results.
Jeimuzu is offline   Reply With Quote
Old 09-10-2009, 10:35 AM   #8
Tech Rookie
 
Join Date: Dec 2007
Posts: 13
Default

I sealed up the backplate and checked the sleeve for possible damage. The piston and sleeve were fine, and after letting the sealer cure all is well. It idles fine, and I can finally move on to tuning this beast.
Jeimuzu is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Air leak beneath Heat Sink? duratraxrc Nitro Off-Road 7 08-28-2008 12:04 PM
Revo 3.3 air leak? Please help!! matts6887 Monster Trucks 7 07-25-2007 06:15 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 12:22 AM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net