engine makeover

[indusnativictus]

i run the whole tank thru, so i haven' had the problem of plugging the stinger. in emergency cases when i really need to stop the engine, i posistioned my fuel line to pass at the back of the shock towers so that i can i easily pinch it if i have to. no problem bro am willing to help you with ur problems on our same engine.... and today have opened the head removed a shim (silver i think) tweak the needles a bit , am gonna run it like hell

i did refueling on the fly on my previous engine( nitro star S-25)and it was fine have not done it with the sts though cause temps are already high so i need to cool the engine first ( for engine care) b4 i have another run

 

[mrvern_04]

well, as i beleive i have mentioned before, i out of a job right now, but when i get back into some cash, i'm going to get the saftey engine stop set, and i need to buy a roto backplate for my engine, since all (4) of my pullstarts are broken. i've got such crappy luck, especially with this hobby so far, i try not to take many chances. i took apart my engine yesterday and found that pretty much the entire crankcase was full of nitro, but i have no idea if that was the problem, since i have no starter! lol! thanks man!
oh yeah, at what point do you re-shim the head? i've only got about a half gallon through it, but i only run 20% nitro i think...should i have already re-shimmed?

 

[indusnativictus]

flooding could make starting difficult if not impossible. when had such a problem on my previous engine i did the following: remove the plug roto start it while covering the plug hole with rug or turned truck over and let the nitro escape or just leave it there for about twenty mins, tops let fuel evaporate.

How do you stop your engine? If it is plugging the exhaust or air filter, then it will flood the engine fast.

stopping the engine this way really floods the engine and pushes the dirt from ur filter into ur carb, into ur engine


i am about 2 gals right now, i removed the plug and tried to turn the flywheel past the tdc, minimal resistance so time to remove the shim. oh by the way the type of shim being removed varies with the nitro content of your fuel the thicker the shim removed the lower the nitro content should be

 

[indusnativictus]

well today the nightmare begins, i noticed that when i ran with the sts engine, i noted that when i stop, the truck still has momentum and moves forward, adjusted the idle, worked awhile then returning to the same problem, adjusted the low speed and idle for a short while it works but then it comes back again....... time to look at the carb, opened and cleaned it... sealed it......reassembly time...... when i connected it to the throttle linkage the carb does not return to the closed position.... whew tried different angles on the carb still to no avail, tried repositiong the return spring sometimes it works most often it doesn't........anybody has this experience, your solutions will be highly appreciated.

 

[mrvern_04]

well today the nightmare begins, i noticed that when i ran with the sts engine, i noted that when i stop, the truck still has momentum and moves forward, adjusted the idle, worked awhile then returning to the same problem, adjusted the low speed and idle for a short while it works but then it comes back again....... time to look at the carb, opened and cleaned it... sealed it......reassembly time...... when i connected it to the throttle linkage the carb does not return to the closed position.... whew tried different angles on the carb still to no avail, tried repositiong the return spring sometimes it works most often it doesn't........anybody has this experience, your solutions will be highly appreciated.

first off, the guy that i bought the STS D30M from, told me that there is a problem with the O-ring on the low speed needle...and that after a while, it wont want to hold a tune, and the needle will want to float around and what not. when he sent me the brand new engine, he actually taped a new O-ring to the top of the box...he says its not the exact size, but once replaced, you shouldnt have a problem with that O-ring again. so...that might be the problem with your lowspeed needle....or, could be a clutch shoe hung up on the bell.
couple questions...
is it a problem with the linkage?
or is it a problem with the carb itself?
is the brass piece that is on the end of the slide (the ball that the linkage connects to) aligned properly?
have you oiled it up really well after cleaning?
i remember with this motor, when i first got it, the slide was kinda tight, and sticks a lil bit until ya get some oil on the slide.

is the carb slide in at the correct angle? i think there might be a groove (i could be wrong) that is on the slide, which the idle screw rides in....also, if you have the idle screw in too far, it could simplyblock the path completely.

 

[indusnativictus]

i think the initial problem was with the o ring, cause when i opened it the ring was in two pcs , changed that, on assembly i noticed that the carb would not fully close unless i apply finger pressure----moved the barrel( its oiled by the way)and noticed that it will only close fully at a certain angle..... and so did this . tested it without the engine running, just turned on the electronics..it seemed to work ok......now time to do actual testing..... perfect but only in a few minutes....again the problem came back(engine still revving despite 0 input...looked at the carb its fully closed and yet its revving... opened the idle needle, adjusted the needles to no avail.......guess that somewhere there is leak and it was drawing fuel and air from another place....dunno

 

[mrvern_04]

you could have an air leak around the carb throat, or possibly on the engine backplate. running lean (air leak) would cause it to rev high. after a few mins of running, heat and vibration could make the leak pop up on ya. other than that...i dunno...

 

[indusnativictus]

yup , changed the carb to an hpi k 4.6 one, run it, again on high revs the problems recurred, removed the engine and lo and behold the backplate was smiling lol..... its leaking my god.....now opened it and placed silicon gasket (high temp rtv) on the plate... will hope that this will work. oh i also removed the bronze shim on the head and returned the silver one(thicker) just so to increase to compression space.....am i on the right track bro?

 

[mrvern_04]

yup , changed the carb to an hpi k 4.6 one, run it, again on high revs the problems recurred, removed the engine and lo and behold the backplate was smiling lol..... its leaking my god.....now opened it and placed silicon gasket (high temp rtv) on the plate... will hope that this will work. oh i also removed the bronze shim on the head and returned the silver one(thicker) just so to increase to compression space.....am i on the right track bro?

yup! sounds like ya got 'er covered. i'm just not sure about which shims to remove...i will have to look at the info that the vendor gave me about running this engine. but, the shimming, i dont think will be a huge issue...more important was the reving! the shimming i've been told is mostly to do with the nitro content, set up for 30% from factory, and after break in you should remove one of the shims. i will check on that info for ya. good luck man!

 

[indusnativictus]

today, i'll let everything rest and let works set...... tomorrow will update :drink: :stickup:

 

[indusnativictus]

te' rest is over. time to put the works to the test. heeeeeeeya the beast has ressurected -:jet: problems..... overrev.... thing of the past....guess that's the lesson there -seal your engine. thanks everyone and allllllllllllllllll.:dancin: :contract: