kordasn

Hello again,

We're having trouble with the MT2; it seems to be stalling in the low end. Specifically, if it stops, sometimes it stalls, the idle is not set that low (or high), farily close to stock. The needles also are fairly close to stock. When I start the car, it starts pretty well and the top end runs well, but if I let it sit there, it will stall pretty quick. I have checked the clutch springs, they are fine, the back diff is fine, I didn't check the front one yet because I am lazy? From what I can tell, the majority of the truck is fine... I don't really know what to do. Suggestions?

-Matt

eminentguitar

Does it smoke alot? It kinda sounds like your low speed needle is too rich. Try turning it in a little bit and see what that does. Is the engine broken in? If it is they usually dont run well on stock settings.

KeithjV

I agree with eminentguitar, it sounds like you need to lean the lsn a little.

kordasn

I'll give that a try, but I believe I've tried it before (maybe?), what I usually do for the LSN is to do the pinch test. At any rate, I'll give it a try and see what happens

-Matt

KeithjV

Is it stalling when you apply the brakes or just when its sitting idling? You might have to adjust the carb linkage a little to keep it from shutting the carb completely when the brakes are applied.

kordasn

Nah I wish it were so simple

As far as I can tell:

-There are no air leaks
-Linkage, idle set properly
-Clutch is fine
-Diffs are fine

I adjusted the LSN a little leaner, ran it for a while, stalled. A little leaner, ran it, stalled. I tried that for a while, but it didn't SEEM to make a difference

=/

eminentguitar

Thats strange man. How are your temps? the top end still works great? pulls really hard?

KeithjV

Does it stall after its been idling for a while or as soon as you let off the gas?
Did you check the glow plug? Maybe its time for a new one. Is the fuel fresh?

kordasn

The high end temperature is hot, which I can reign in by adjusting the HSN, but it has to be adjusted to be (fairly) rich for the temps to be successfully below 250^, almost 1 full turn I suppose? The weather here is [retty cold and fairly humid (http://www.theweathernetwork.com/weather/CAON0441). It is possible that there is a small air leak near the interface between throttle linkage arm (on the carb) and the o-ring between them and the carburator's valve. Alternativly it could be on the idle screw I am not sure if this is supposed to be airtight or not?, but it's not a big leak, I had to blow pretty hard, and a very subtle amount of change occured.

Usually it doesn't seem to stall until I move the car. If I move it, touch the gas, touch anything, it seems to stall... I have not tried just letting it sit there, but I would guess it would stall. Fuel is fresh. The glow plug is fairly well used, I can try another one, it's the stock one (8? 5?), should I try a different one for the weather? Also arn't the glowplugs just for starting? I thought after they start they have no current and the compression and heat from the ambient combustion; it starts pretty well each time, the glow plug has a solid yellow glow (I can make it glow white but I usually keep the current down on it when starting).

I can try the glowplug immediately from my firestorm and see if it makes a difference.

KeithjV

An air leak can wreak havoc. Its easily fixed but will drive you nuts till you find it.
The glow plug keeps the engine running. The igniter gets it hot to start the engine, after that the fuel igniting keeps it glowing. If the plug is going bad it will cause the engine to stall out when the igniter is off. Try changing the plug or try running the truck with the igniter still on the plug and see what happens. Cold damp weather you want a hotter plug, warmer weather you can use a medium plug. Also the smaller engines generally want a hotter plug as well.

You can use some petroleum jelly to seal up the needles or some green slime. You can use RTV sealer like this to seal the rest of the engine up http://automotive.hardwarestore.com/...er-662054.aspx

kordasn

Hi Keith,

So the glow plug is not quite what it is in a diesel-truck engine? I havn't changed it yet, but will.

Specifically with the leaks I have, though I am going to fix them, I am not sure if they would be causing such a problem; as the engine would be made to run leaner then. Moreover, I am not really sure how to specifically use the RTV gasket maker to repair the seal on the idle-screw or the o-ring seal from the valve to the throttle arm. Any suggestions on that front?

-Matt

KeithjV

Use the petroleum jelly on the idle screws. It wont dry like the RTV will but it will make a nice seal and keep the washer lubricated.
The RTV is for the back plate, around the carb where it inserts into the crankcase, and you can put a little on the fittings for the fuel line intake. DONT put the RTV on the needles though or you wont be able to turn them.

caspar21

we had one mt2 with the original hpi .15 motor that would die at idle like that.. turned out the pressure line to the muffler had a hole in it and the motor did not have enough pull to get fuel from the tank at idle without the pressure line helping.

other thing i can think of.. weak plug(mentioned already)

plugged fuel intake in the tank.
debris plugging the carb.

good luck.

eminentguitar

kordasn When you do the pinch test how long does it take to shut off? Does it rev up before it shuts off? and how far away from the carb are you pinching the line? If these problems are from an air leak then it shold shut off really really fast because its already running lean and wont really rev up much when you pinch the line. If your header has a leak it may cause the fuel system to be under preasured just like casper mentioned.

kordasn

Yesterday I replaced the fuel lines thinking (hoping!) that could be a souce of the problems, unfortunately not. I will check tomorrow within the fuel tank for debris, but how do you check for debris plugging the carb? I am not sure that this is the reason for the problem, but I don't want to rule it out without checking. The car's (relativly) new, with say max 20 (maybe 30?) tanks in it, and it's not been in dust, etc., I'll take a good look if you can tell me how.


It takes maybe... 5 seconds? Not what I would consider long. It revs up slightly then turns off (I believe this is how it should, correct me if I'm wrong). I'm pinching it maybe an inch away from the carb? I believe I checked for a header leak, but I will check again to be thorough.

I just want the truck to run well!!!!!!!111111111eleventeen

Thanks for the suggestions so far, I'll report back sometime tomorrow with the results, HOPEFULLY positive?

-Matt

KeithjV

Can you take some pictures of the truck. Sometimes it easy to spot a problem you might be over looking.

eminentguitar

well that pinch test sounds perfect. When my header was leaking I could plug the exaust when it was running and it would stay running.

caspar21

only way to check the carp is to disassemble it.
pull the needles out.. look for scum.
take it apart and clean it. always good for it as long as yur gentle.

kordasn

Here it comes, it's gonna be long since I took quite a few (Sorry you have to click-through, I didn't think it was fair to anyone browsing the page with a low-speed connection deserves to be bogged down):

Fuel tank/lines:
http://i29.photobucket.com/albums/c2...2/P1000562.jpg
http://i29.photobucket.com/albums/c2...2/P1000563.jpg
http://i29.photobucket.com/albums/c2...2/P1000564.jpg

I havn't seen any particulate in the nitro fuel jugs and nothing in the 500cc bottle; I don't see any here, hopefully I can count that out.


Engine - Driver's side
http://i29.photobucket.com/albums/c2...2/P1000559.jpg
Engine - Driver's Side2 (yellow is flashlight)
http://i29.photobucket.com/albums/c2...2/P1000551.jpg
Engine - Rear
http://i29.photobucket.com/albums/c2...2/P1000560.jpg
Engine - HSN
http://i29.photobucket.com/albums/c2...2/P1000558.jpg
Engine - LSN
http://i29.photobucket.com/albums/c2...2/P1000557.jpg
Engine - Header(L)
http://i29.photobucket.com/albums/c2...2/P1000556.jpg
Engine - Header(R)
http://i29.photobucket.com/albums/c2...2/P1000553.jpg
Engine - Header2
http://i29.photobucket.com/albums/c2...2/P1000552.jpg
Engine - Roto
http://i29.photobucket.com/albums/c2...2/P1000555.jpg

Although there is grass-matter around, overall it looks pretty clean to me. No terrible 'oil stains' that would show from typical leaking gaskets or whatnot.

I really am not sure what to say, the problem is almost like torture: the car runs pretty well normally, except when I move it from idle... I wanted to ask you if I were to swap the engine out and put my FS engine in, do you think that removing the header (because the FS header and MT2 header are aligned oppositely, or something) will require a new gasket?

-Matt

JELLEY

Hey .. Just a bit off the subject
just bought mt2 g3.0 - ive ended up unlucky with it reciving a faulty 1 - the front left wheel just falls off randomly even when comlpletly tightened- the rear right diff shaft just dropped off and wont go back in and the brake gets stuck 2 the pad however i adjust it -and this is running on a dead flat grass area not going full throtol yet
reli disssapointed and have sent it off not shaw if i want another replacement sent tho-Does this usually happen or is it just me and should i get another1??

caspar21

it does look good.
i noticed no fuel filter.
if you pull the high speed needle out, is there a sludgy matter on the tip?
this could mean that something did get through the fuel system.

this would be my prime suspect now.

kordasn

I'll take a look, and wiith respect to the fuel filter, I think my FS is the same, do neither come stock with a fuel filter? Maybe the camera angle is bad. I'll also check the needle. Also, I replace the glowplug for a second time, it SEEMS? to be running better, but I only got one tank through it.

Also, given that I have a heat gun, how important is it to keep the temp below 250. From what I am seeing, the performance through pinch-tests and acceleration (and topspeed) are showing me that the car is too rich, but the temperature is close to, if not above 250 (if I'm giving it WOT).

Thanks once more for the help so far.

pede_187

How is the MT2 G3.0 RTR?

caspar21

g3.0 mt2 is a smokin vehicle.
great for bashing and it keeps up with 1/8 buggies on the short track

pede_187

and how would it compare to the 18SS+ kit?