Ihave had my eathquake 3.0 since christmas. Ihave about 1/2 a gallon through it and Icant get the engine tuned. Ihave tried everything it either runs way to rich or seems to lean and wont idle very well at all. Idid try sealing it Ibought a new gas tank cause it had a air leak coming from it and Iam totally fed up with it. Iwould have sold the thing days ago but it was a gift from the wife and she is already pissed enough about it Idont want to further her frusteration by me selling it. Anyways Ihave came to the conclusion of replacing the engine with something better and Iwas looking at a dynamite .21. It looks like it would work Iwanna know what you guys thing. Im not looking for a top of the line engine here just something better than what Igot. I m not here to bash on redcat Ido like the truck when it runs the things rips. Any opinions on the matter would be appreciated.

Perhaps you got a bummer of an engine, it happens to the best of us. Ibelieve Redcat has an exchange policy.
SH engines are really nice and they are OEM for a lot of other name brands.
Have you tried different fuel? Iuse Sig Champion 15% nitro with 20% oil at a 50/50 blend of castor to synthetic and my engines are very very happy.

You could an exchange for the SH28 or you could get the dynamite engine. OS also makes a nice 21 size engine that will fit. either of those are a good choice.

So you think the dynamite engine would fit ok with no problems?

Iwas just working on an SH21 in an Earthquake today and it was totally sweet.
Check your clutch spring, this one was broke and it really made it run funky.

Iwill have a look at it why wouuld that make it run weird though?

It would run bad, because the clutch shoes would be dragging down the engine every time you hit the brakes and if it stops moving the engine will die.

the sh .21 engine is what i have in my earthquake and its a sweet engine holds a tune very well when it finally kicks the bucket ill be putting in a dynamite engine in it prolly the .26 one

THe only thing Iworry about changing the engine is that Inoticed a lot of rc cars they have a screw on the end of the crankshaft to hold everything on, Inoticed on mine and a few other redcats its a c clip Idont know if this matters or what just thinkin about it probably worrying about nothing.

I am experimenting with swapping out the SH21 with the SH28. Ibelieve if I replace the clutch assembly with one from the 28 it should drop in. I will know more tomorrow if my parts arrive.