Air Leak Symptoms? What are they?

[Diver6127]

i was told that carb cleaner would work as well. I don't know about wd-40. I only have experience with the nitro cleaner. Theory behind it is that the introduction of this other combustable liquid creates an extremely rich situation that will cause the engine to stall. If there is no air leak, no stalling. An air leak will suck in the fluid and stall the engine.

I can only assume that WD-40 is ok, but I don't want to say "sure, why not?!?" and then be held responsible for the engine breakdown.

 

[MyJeep]

I use disc break clearner to clean mine. It is good but you have to becareful not to spray it on stickers or the body. Carb clearner will work out right. WD-40 is good to keep the rust away.

 

[RX7Maxx]

Most any liquid should work as long as it does not eat your painted or plastic parts, i use those ideas on automotive work. It will either make it rev up or stall but you should see the difference.

 

[CorradoPsi]

wd40 should work, but id use something that evaporates a little quicker like nitro, brake or carb cleaner.

 

[nitro-king-2007]

hey i am haveing the same problems with my newly rbuilt trx .12 humm. i if you find out the proulbem plzz PM me .

 

[Rolex]

Just for those of you who want to keep up with the outcome of this problem, I just tore it apart today and did the RTV seal on the carb and the backplate.
I need to let it cure for 24 hours, then when I get the engine re-installed tomorrow I'll take it to the track and test it.
I'll probably have the final answer for you then.
The major suspect was the backplate. When I took the EZ start off, oil poured onto my hand. I can't believe the one way bearing even grabbed, with that much oil in there.

 

[CorradoPsi]

sounds like you most likely found the problem then. how is the clearance where the starter shaft comes through the backplate? it isnt worn at all is it? i resealed the backplate and locktited in the screws on psunitro's rusty not that long ago. but the whole starter assembly on his came lose. the backplate was backed away from the block not the starter from the backplate. i guess traxxas doesn't think thier motor needs locktite, i say it does.

 

[Mr T-Maxx]

This is the best thread I've followed in a while. Great stuff. Also a breath of fresh air to hear someone not complain about the TRX 2.5. I've kept all three of mine tuned and I'm a Noob....This must mean I'm a tuning expert. :thankyou:

Rolex; Keep us posted.

Diver; Keep dispensing the wisdom.



Mr T :fro:

 

[Rolex]

Okay.....It's been delivered.
It was DEFINATELY an air leak in the backplate. I also sealed the carb throat while I had the engine out, but the oil that poured into my hand told me the problem was in the back plate.
I think the leak was too small to be detected by Diver's method, or maybe it has to be at running temp for that to work. It was retuned today since any tuning done on it Saturday was no longer right because of the leak. Once the carb was readjusted, it ripped. 235 with hard running. ACNCM head.
Today I took home a Truckzilla with the Hot Bodies .46 that has the same problem.

 

[Diver6127]

Oh yeah, it has to be warmed up for that method of finding the leak since the aluminum will expand with heat. Sorry, forgot to tell you that bit of info. IF the leak is around the carb, it'll cut out almost instantly.

 

[El Pirata]

That's what's driving me nuts. It's inconsistent. Sometimes perfect....just perfect, then it takes 30 seconds to idle down....sometimes. Temps are perfect, performance is perfect on low end and WOT....sometimes. I'm the designated tuning wizard at the track, so I know the carb is adjusted properly now but I can't account for why it changes on its' own. I'm still hoping for a reply from someone who has been through this to nail it down. I brought the guy's car home to work on it tomorrow, but need the info before I start tearing things apart that won't make a difference.

Dude, in all honestly please PM me if you get the real solution to this one because the Anti-Christ has been having this problem and it's gotten me so PO'd I was ready to use the Sledge-O-Matic to adjust the $400 engine.

 

[Rolex]

Good point, Diver. Either way, I knew it had to come apart, and while I was working on it I realized that it was probably a small leak, and the problem didn't become apparent until the engine was warmed up to running temp.

 

[CorradoPsi]

glad to hear you got that little bastard. good job.