New 4.1 Break In Problem

[sgtsavagex]

Hello everyone. My Savage X crankshaft snapped in two during a session last month. I had less than three gallons of fuel ran through it. HPI customer service replaced my engine stating that is was a defective engine. However, I bought a gallon of Backyard Basher on recommendation from my LHS and tried to begin the break in process today. The engine revs very high after a few minutes and reaches temps of 230F. I have shut the engine off everytime it revs and tripled checked that the factory settings are on flush and 1mm carb opening. Any ideas? The fuel is 20% and contains 16% oil ratio.

 

[Jeremy]

so howe many tanks do u have threw it yet??? thats kind of a differnt problem airfilter ok?????

 

[sgtsavagex]

Not even 1 tank! The airfilter has been cleaned and is not the issue.

 

[Jeremy]

do u have a different kind of fule u can try (might ba a bad batch or something) its a long shot but never know check for air leaks also sounds like u might have one (even brand new engines should be sealed

 

[sgtsavagex]

How do you seal an engine? Its just frustrating because my first engine was very easy to break in.

 

[Jeremy]

http://www.rchobbies.org/engine-tuning.htm read this the second page is about air leaks and stuff hope this help u out keep us posted

 

[sgtsavagex]

Thanks. I will try that later today and let you know.

 

[sgtsavagex]

Run,

Thanks for the article. I had an airleak on the carb bolt. I idled a full tank off the wheels and had to richen the low speed another 1/2 turn. I will continue the break in tomorrow.

 

[Jeremy]

what did u use to seal it High temp sealent right??? let it sit after u apply it for at leat 12 hours and at room temp Iam glad that helped it tell u allot about everything later bud keeps us posted

 

[sgtsavagex]

I used some Mil-Spec RTV and it seems to have held. The break in is still going smoothly (I plan to run 6-9 tanks of fuel before full throttle). I want to have this thing bashing again this weekend. Thank you for all of your help Run!

 

[Jeremy]

no problem my friend, so it doesn't rev high anymore after u sealed it????

 

[sgtsavagex]

No more high revs. Although I do have the low speed 1.5 turns out from flush (factory setting) Idle temps are around 210 F. Before my idle temps were 250+

 

[Jeremy]

thats about right man anymore ? just ask ok

 

[Jeepguy]

Any air leak will cause a lean condition, lean shows up as high revs, and high temps.. that's why you were seeing just that problem.. Good thing you checked and sealed it up.. You should also check and seal the carb neck and backplate. This seems to be a lot more common than it should be even with new engines!