damage from running lean
 

Perhaps this is a newb question but being a newb I guess that is OK.:)

I believe that I ran my HPI RS4 RTR 3 (.15FE stock motor) too lean and consequently too hot. The car was flat out hauling ass when I pulled it out of storage. After 2 tanks the car started to lose top end and just bog. When I pulled it in and pulled the body I noticed the heatsink was way hot and the purple anodization was actually dulled. I shut the motor down and let it cool off. Now the car will not start what so ever.

I pulled the sleeve and piston and crank. All look to be in good shape with no scoring or visible damage. When turning the motor over with the flywheel it does have compression but without a gauge I can't give a number. The glow plug is good.

I am out of ideas on what to check so any help would be appreciated.

RE: damage from running lean
 

U say glow plug is good. Did it lit up when u checked off the engine. try a new plug just in case. Running lean can damage the plug easily. Good luck

RE: damage from running lean
 

When your motor is too hot you should not stop it immediatelly. If you stop it just like that you are cooling it too fast. (Due to temp difference compared to ambient)
Cooling too fast makes the metals deform so this is where your problem may be. If you measure your sleeve with a caliper you will see that it is not round anymore but a little oval shaped. Since it has compression you will manage to start it but it wont be as fast as it used to be or it may give you some tunning problems if you run it that hot as you described.
When your motor is TOO HOT dont shut it off. Richen the fuel and take off the lexan. Then run it around with about 1/5 throttle so that the motor temp will fall. Then, once it reached normal temp, shut it off.

RE: damage from running lean
 

now thats what you call some good tips. thanks drf.

RE: damage from running lean
 

NO NO NO

When it is running to hot, keeping on running it until it blows up... LOL

I am just kidding.... Just could not resist.

RE: damage from running lean
 

why is everyone so stupid. all you do is flog the damn engine until it dont work no more. then you kick the piece of $#!^ then go buy a new one.

(someone i know seriously does this)


but yeah, get a new plug and see what happens

RE: damage from running lean
 

nice tip drf cuz i always do that sometimes when u check ur temp and u see its too high u turn the engine off automatic now i know

RE: damage from running lean
 

Good tips. I didn't even think about cooling it gradually.

BTW the plug lights up when I hit it with a warmer out of the motor. When I try to start the car it just turns over. You can here it puffing from compression but it doesn't even try to kick over.

RE: damage from running lean
 

I would not worry about any engine damage if you only had a couple lean runs. A couple lean runs does not help your motor but certainly will not ruin it.
Even a new engine with a couple runaways on it will run fine but may not have the life span as an engine that has not had runaways.

Im not saying to go and run your engine lean and expect to have long service from it. Im just saying that some opinions exaggerate what is actaully happening with these little engines.

In my experience I have run several engines very lean on purpose while racing and still got 4 + gallons out of em. I have never worried about how the engine cools either and I seem to get plenty of service from all my car and plane engines.

There may be other issues as to why your engine is not starting.

Dbow

RE: damage from running lean
 

put some wd-40 in it and all will be good :D
sorry i couldnt resist it [sm=lol.gif]

RE: damage from running lean
 

use WD-40 as fuel and all will be right in the world........

RE: damage from running lean
 

I think you got your carb not tuned man.. I've had that problem too.. mine's been ran lean before also.. I haven't found time to get a rebuild kit for it.. I want to.. and slowly break it in again.. but it runs fine for now.. won't spend the time working on a engine that I tuned right...

RE: damage from running lean
 

I thought it might be the carb settings too. I readjusted them back to the break in specs and nada. I have yet to find some time to really sit down and work on it lately though.

RE: damage from running lean
 

throw your engine out the window and get a better engine.