Hi there everybody! I am new to nitro racing and am having problems! My MT2 doesnt want to keep running at idle, well it idles ok but doesnt starting off again if its been sitting for more than a few seconds, it just seems to rev a bit then die. Starting is not a problem and if I do a high speed run and come to a stop then instantly gun the throttle its fine.
I have gone right through the ranges on the low speed mixture but either way doesnt seem to improve it any (from the flush setting). I am running an OS R5 plug, and have tried an OS 8 but the same thing happens.
What plug should I run, they (cen recommend cold, thats why I went for the R5, would an A5 be better?)
It was running fine the other day but I think the engine got a bit hot, and the next time I went to run it I had these troubles. I have also changed from 10%nitro to 15%.
Have included a photo of my diff cup mod.
Since I need to send overseas for spare parts what do you suggest I have in the way of spares/upgrades.
Toasted my steering servo after about 12 tanks, (that radio gear is CRAP) upgraded whole radio st to a JR cobra with ES 579 hitorque steering servo, WOW what a difference on the steering!!!
Thanks!

Your dif cup mod looks the business! Dont really know what could be causing your engine troubles though, never had that problem with any of mine. As for the spares, definitely keep a couple of packs of cvds around, they tend to bend pretty regularly. Maybe two packs of upper and lower arms would be a good idea to keep you on the road. Other than that the cars are really quite solid, although like any car, if your gears aren't meshed correctly you will strip them so possibly order a second set of them too. Hope this was of some help.

azzman ,sounds to me like ur engine maybe leaking ,or drawing air in other words ,try using high temp sealent around neck of carb and the back plate ,is their any oil leaking from or around head ,cause ur head bolts [or one of them] could be loose ,some else might know a site with diagrams on how to seal ur engine. thays all i can think of now
hope this.... madmark

been thru many of the same engine problems that you describe and it seems that when the engine has been run hot, it tends to want to stall after you get it running again... air leaks would show up as a lean condition... try leaving the low speed needle flush and work more off the high speed... again.. you will have to experiment as to which way to go... also, for the idle, try to raise the idle speed on the carb to just below when the clutch engages... it will allow the engine to run without stalling as much....

I use the O.S. A5 plug myself and think that it works better than the R5. You should seal the engine up with high temp silicone (should be able to find a how to on the engine forums) and reset the needles back to stock specs and then re-tune.
15% nitro is still kind of low CEN recomends 20% with 18% oil, I recomend O'donnels 20% RTR fuel if it is available in your area.
As far as spare parts this list should keep you going for awhile,
GX12 Differential cups
GX15 axle shaft
G84307-01 47T Spur (1st gear)
G84307-02 44T Spur (2nd gear)
Glow plugs
FF063 Screw set
FF012 teflon clutch with spring
FF009 Body mount set
FF046 Center dogbone
FFS003 Unversal swing shaft
FF003 Suspension arms
If you don't have one a temp gauge.

rolland

Thanks for the comments guys.
I did notice some oil leakage around the bottom of the head so checked all the bolts, all were sweet so it looks like I need to seal around the head joint.

azzman.. did you by the truck new or used because i'm trying to figure out why you are having so many problems with the engine.... This motor nt-16 is a tank and I have yet to develope a leak of any kind even after almost 5 gallons of 20% thru it.... I take off the head occasionally just to look inside and have never developed a leak... are you sure everything is flat and nothings warped? The only turning issues I've ever had traced back to a bad carb spacer which cen promptly replaced (the whole carb) free of charge........ I keep trying to convince myself to replace the engine, but it works too well and I can't justify the money....

cenracer...bought it new dude and had it running **** hot after break in....have taken the head off again and it looks sweet there, although there is a bit of oil around the fins. Could it be carby?

Or could it be leaking around the glow plug?

I would check the glow plug... sometimes when its hard to start, loosening the glow plug to relieve compression makes it easier to start. If you forgot that you did that, it would explain the fuel leak... the carb could be a problem, but usually they don't leak up to the head..... clean it off and see if it comes back.... another could be the bearings on the engine... the rear usually leaks at some point and the front can leak... according to cen its not a big deal....

azzman ,sounds like the glow plug is leaking try that first and illiminate as u go

1 cen mt2+extra headshim+18 piston and sleve+mccoy59coldplug+30%nitro=a nice view from behind since no one can catch me

I narrowed it down a bit more, no leaks around glow plug, it seems that it runs fine while I have the glow plug ignitor on, so I replaced the glow plug, still the same, rumour tells me that it must be running rich on the low speed needle, so I slowly wound it it in until I got some joy, it meant that I had to lower the idle speed as it started to run away with no throttle input.
What mystifies me is why I have to go so lean on the low speed to get it to run!!???? [&:]

are you sure its really lean on the low side? could the low speed needle be damaged in some way and giving a false reading.... I took my old carb apart the other day and found the needle was dented at the tip, which explained the difficulty in tuning the truck.. the new carb directly from cen required very little adjusting especially the low speed...

how come u used an extra shim ,is it needed or is it that u up % of nitro severly and needed to change ignition timeing to compensate ,let me know cause im thinking of this conversion myself
thanks

Spare parts I would recommend:

Diff cups (or just upgrade them like you did...you WON'T break them again)

Spur Gears

I upgraded my brakes to metal disc and metal plug, like a $15 upgrade at ehobbies.com (go to the cen option parts)

Upgrade servos

FailSafe

Air Filter

Pipe

Ok, not all spares (upgrades!) but they will help!

Took the carby to bits and it all seems fine there.
I reset the low needle to flush and had the high speed at 2 1/4. It runs brilliant at this setting as long as you dont stop and idle, ie, you can gun it, then slam on the brakes and come to a complete halt then gun it again and take off with no problems but if let it idle for more than say 3 seconds it just dies suddenly, even set at fast idle..............ggggrrrrrrrrrrrr!!!! [:@]

You could have had some dirt or grime in the carb or possible air leak around carb that
re-installation solved.
The factory settings on the carb is 3 turns out on the high speed needle and 1/2 turn in from flush on the low speed needle, idle gap at 1 to 1.5 mm. Try the factory settings and re-tune.




rolland

Well I have solved the problem, and it was quite simple really, my engine only wants to run on 10% nitro fuel (which is what I ran it in with). Many people told me that it shouldnt matter, but in this case it did.
What fuel do people usually run their engines in on? I have heard you should run in on the same nitro content as you want to continue with, but then the run in fuel we have over hear is 5% nitro with high oil content?

always on 20% blue thunder.... may not be the most popular over here, but never had a problem with it....

So your saying dont worry about special run in fuel? Hey cenracer, any idea what header is needed for an OS 18 CV-RX in my MT2. What about a tuned pipe. Do you know if the New Era Hi torque Ripple Tuned Pipe is any good?

azzman never heard of that before , does'nt sound right at all

see if you can get in touch with poor judgement on the os pipe... I still run the stock engine in the truck... no need to change... I don't see the need to run a special break in fuel especially lower nitro content... I run whatever I get which happens to be blue thunder.... I have seen the new era pipe and it looks nice... I have a friend with it on his truck... with the exception of it being louder, I don't think its any faster....

I broke my MT2 in with 20% trinity monster horsepower and that is what I,ve been running ever since and it runs great now that i have it tuned (took a WHILE but eventually got it). Also I,ve heard from a lot of people use the same fuel that was used to break it in.

CEN recomends 20% nitro with an 18% oil content. When it comes to fuel, I have always followed the manufactures recomendations whenever possible. O'Donnel 20% RTR fuel is what I have always ran and I am almost done with my 5th gallon and there is no noticable power loss so far.


rolland