normally I'm pretty good at figuring out whats wrong but this has me stumped. the tune is good and it'll run good then nit just dies and the idle gap is good but it seems like it wants to go,i figured maybe the clutch shoes were going but they look good. like i said it'll run up and down then it just quits ????

hum
maybe start looking for air leaks.

do you have a temp gun? if so, check the temps as it runs. If it continually goes up then a bad gasket could be to blame. Air leaks can allow a tune to SEEM good, but at certain RPMs the motor wont get enough fuel/oil.

That could also explain it revving high under idle.

check the exhaust gasket, carb gasket, glow plug washer ect.

yeah I've got the duratrax temp gauge. I'll give that a try and replace the gasket on the block itself and see if that helps.

I had the same problem with my Monsoon. It would fire right up, have great smoke and never feel too hot until about half a tank, then like you said, just quit. Mine would be so hot you could hear the fuel boiling in the bottom end and you could see the fuel being pushed out of the carb and back into the tank. I was positive the tuning was good after checking the needles, i couldnt bring the HSN out anymore without it litterly fogging the yard. So after ripping everything apart and sealing everything I could, I put it back together and it would do the same thing. I tried running a colder plug, more oil content, nothing helped. So I eventually just turned everything back out, fired it up and let it spit some fuel for a minute. Turned the HSN in about 1/4 turn to slow down some of the fuel dumping out of the pipe. Gave it a little throttle to see how it wanted to respond, it was loading up and sputtering. Turned in the LSN about a 1/4 and was able to run it. Fine tuned the LSN about another 1/8 in and my temp problem was solved.

how far out did you bring the LSN ?? Till its flush with the carb body and then tune from there ? I'm guessing that may be the problem too the local hobby shop guy said the same thing. Also would the exhaust gaskets from a .21 engine work on the . 28 ?

I'm not sure about the gasket. I've only had the SH .18 and .28 engines. As far as the LSN, as you've probably noticed, its hard to tell where flush is. I just backed it out until it was obviously too far. I figured worst case scenario was to get it started and find it bogging down from too much LSN. That's exactly what happened. I turned it in about half a turn where it at least wanted to try and run but was still very heavy. Then I just fine tuned from there. Funny thing is, I have no problem with the needles, but I never thought my LSN being too lean would make it run hot. I guess the HSN was compensating for the LSN. You learn something evertime you play with these things.

well as it turns out i was till having problems...I was banging my head on the wall for almost 3 weeks with this truck,so I broke down and brought it to the hobby shop who sells Redcat stuff. He ran it and was having the same problems as me and I forgot what he told me but pretty much he said I need a new engine ....I don't understand how this possible with that not much fuel run through it .

2 things could have happened...
there was a defect in the motor that made it wear out quickly (hey, it sucks but it happens)
or 2, it wasnt broken in properly. That one will always cause a motor to be impossible to tune right as well as cause it to wear out quickly.
Also, it the motor was ever run tooo hot. It only takes a couple of minutes of it running to hot for it to be toast.

I know a few people who think they can tell how their motor is running by sound or by the "spit test".
I use a temp gun. Its the only sure way for me to know if my motor is too rich or too lean.

Sorry to hear the motor is done for.

Pull it off the truck and totally disasseble it. At the least, you will get to see exactly how they are made and work.
when you take it apart, check the "pinch"
If you put your finger into the cylinder...you should feel a lip at the top of it. If there is no lip or ridge, then there is no pinch and the motor cannot function right.

who knows anything is possible...well I got sh .28's coming in a trade hopefully this weekend.