Air Leak

[jcori3]

Well i pulled my 2.5. It is a new engine that i put together and got it broke in but it is running hot no matter what i do and it is cutting out and bogging down. I have the needles set at factory settings and still the same problem. So i got the soapy water and all and did the leak test. No bubbles except from around the slide that slides in and out of the carb. Is it supossed to leak there?

[jcori3]

Just checked engine again and all is good except where i took the blue throttle boot off. Where the slide goes back and fourth in the carb i have some air leaking around there. NO air is leaking around the lsn. Just around the slide. So you cant seal the slide cause it moves back and fourth when you give it gas. I dont see any kind of o-ring on the traxxas view. Any idea's? Are you gonna have some air leaking there?

[traxxterbasher]

I would try changing the blue boot,I was having the same kind of trouble with one of my motors....changed the boot and all is good now.

[arceeguy]

Also check the tank pressure lines and make sure the tank isn't leaking exhaust pressure. Usually when I encounter an air leak on the engine, the engine will not even idle correctly. An air leak large enough to upset mid-high speed mixtures will have to upset the idle. If your engine idles OK, you should start looking externally and re-check your carb settings.

[jcori3]

I changed both fuel lines and put new ones on, changed to a fresh glow plug, running the lc3 plug. and checked the tank for leaks using soapy water and it wasnt leaking. I got a different catb that was on my friends 3.3 and put it on. It seems to run a lot better now. The air here is really humid with a temp of about 80 degrees. I am having to run the hsn at about 4 turns and also richen the lsn up quite a bit. I did notice that it runs good and on the top end it shifts fine and doesnt bog orcut out but after some high speed passes it heats up between 260 and 290 degrees. But when i bring it back in and it idles at a stop it starts to cool back down and gets to about 230 to 240 degrees. When i am running it it always puts out a nice trail of smoke. It just seems to get hot on a lot of high speed passes. Is this normal? I was running it in a huge mall parking lot. How hot is to hot for the 2.5? What temp do i never want to exceed?

[aaron1230]

Is air blocked to engine maybe cut the windshield on the engine side to let in fresh air and sounds a little lean on hsn if cools at idle

[jcori3]

I have the hole cut in the windshield, but during the breakin and all this i have been running in a parking lot with the body off.

[jcori3]

I do think i was running a little lean. The air here was really humid and after i richened it up it started to run better. I just dont want to scrap this new engine.

[aaron1230]

dont run it too lean itll kill the engine quick
Im replacing bearings now they said cause I ran it too hot