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help with engine

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XxVASSAGOxX

Gone - bye bye.
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Hickory N.C.
RC Driving Style
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i have a HPI nitro MT.. first start of the day it starts on first pull.. chokes a bit till warm, then is a speed demon for about 2-4mins.. when hot then engine dies and will not restart till its cold.. what can i do? i was told its a rich/lean problem but my smoke is light at idle and heavy at full throttle and is a nice blue color, and i have to feather the throttle to keep it running when its sitting still but if i turn up the idle screw it trys to take off, if i advance the knob for throttle servo on radio i have no brakes, I'm at a lose here spent ALL day on this problem, please help.. also its a brand new glow plug and I'm using trinity monster hp fuel 10%:angry:
 
Have you performed all the standard air leak checks? Also, for future reference, no need posting the same questions in multiple forums. All it does is frustrate the mods...
 
yea sorry about mutlithreads I'm a noob, an today it wasent that cold out id say above 50 and sunny, and I'm using 10% cuz i was told its the safest to run?? should i be using 20%?
and its a nitrostar .15fe
 
yea my bad i didnt see this when i made first post sorry about that man! and how eles do i go about air check? i replace the fuel line and the line to muffler tighted head replace glowplug what eles should i do?
 
You need to make up a soapy water solution. Drain the fuel tank. Remove the air cleaner. Now brush your solution all over the carb base, needles, backing plate, and fuel tank. Place your finger over the carb's air inlet and blow through the pressure line from the exhaust. Look for the bubbles...
 
You could also have a leak in the fuel pickup in the tank. HPI tanks are known for this. The check for this is to fill your tank and start your cold engine. Run it for a few minutes then drain the tank down to about 1/4 full. Fire it back up. If it leans out badly or won't fire and you see air bubbles (gaps) in the fuel line you have a pickup leak.
 
i have seen some bubbles in the fuel line, and i also heard a odd noise today, like water boiling? or the sounds of a car over heating? hard to describe, also, how do i set the needles for a fairly worn engine? i belive my settings are way off and i can't dial them in

also have you heard anything about the towerhobbie st-15? i heard for the money its unbeatable I'm not a pro like u guys i just race around my back yard and can't afford what the big dogs cost .. any ideas is helpfull i want to buy a new rig but keep it fairly priced
 
Sounds like your tune is way lean which is over heating the mill and is preventing the fuel from actually getting to the carb. You need to back off the HSN a little at a time (1/16 of a turn or one clock hour) till she quits over heating. Get a temp gun--it will save your engine. Shoot for 240 degrees then you can start tuning for power...

As for the ST-15 I would shy away from that. Check out RedCat Racing. Good trucks at that price-point. www.redcatracing.com
 
but were do i start the hsn from to do this? full rich setting?

were do i aim the temp gun at. i will get one tomorrow
 
BTW--I just sold a Nitro MT. They are top-shelf rigs. Give it a chance. You have a few issues that can be fixed.

XxVASSAGOxX said:
but were do i start the hsn from to do this? full rich setting?

were do i aim the temp gun at. i will get one tomorrow
Click to expand...

Start from where you are at now and richen it (counter-clockwise). Aim the gun at the bottom of the head. I do it from the side with the body off and some do it from the glow plug hole (at the base where the plug screws in).
 
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yea turned all the way in is full lean counterclockwise is richer,, so i should turn it all the way in and back it out from there? or what.. and the nitro mt is good? how come i keep break parts everytime i take it out.. lol do they make steel replacments like shock mounts suspension arms? the gear in my trans is stripping..
 
No no no. Don't mess with it like that. Just richen it up from where you are now. If you just turn it for the sake of turning it you will have to start over.

There are aluminum replacements but I don't recommend them. Parts are made out of plastic or nylon for a reason--so the cheaper to replace parts break saving the more expensive components. The sad truth is you are going to break parts. We all do. Except Rolex...
 
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well the book says turn in clockwise till it stops then turn counter clockwise 3 full turns
should i start from there?

and what about the lsn what does that do? and were is it.. i only see a hsn
 
Well you CAN start over from factory if you choose. It will be running rich so that's better than where you are now which is going to shorten the life of your engine for sure.

The LSN is on the side of the carb inset in the ring where your throttle servo linkage is attached. It should be flush with the housing. But, from what you describe, the HSN needs the attention. Good luck and let us know if this does or doesn't help. This is just a place to start...
 

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