Hello, im definitely not a noob when it comes to nitro engines but this one has me stumped. My vspec wont idle, not at all. After run it it was going perfectly for my first day with it at the track, idled forever, plenty of power, no problems. I went back the next weekend and started it up but couldnt get it to idle. It wouldnt, i thought this strange so I did the obvious thing and turned up the idle speed, still no result. I can rev it on the box fine and if I hold it slightly above idle it idles fine, but the moment I drop it to idle it cuts out as if for no reason. I thought this was a glowplug problem as idle probs usually are so I replaced the plug and still the same thing! Ive taken the carb off to check O-rings, ive fiddled with the tune, everything i can think of and still nothing. I turned the idle screw in so far at one point that it jammed the carb by pushing against the slider and still it wont idle. Its not a bog down just and instantaneous cut-out the moment it hits idle. ANY IDEAS? im going crazy :P

have you checked if the idle screw is actually holding the carb slide open?

Did you clean the air filter? Are you using fresh fuel? Are all your fuel lines intact? Does your fuel tank have a leak? Is your exhaust lined up properly at the gaskets and not leaking? Did you try leaning the LSN? Did you check your clutch bell bearings or shoes?

Before you start messing with needles check the Clutch?

OK this is interesting and the first time I've heard of this on a V spec, BUT, take a look at the front bearing. If it's wet then this may be the prob. Try Skylines Ideas as they sound pretty spot on too.

Yes, the front bearing is wet, and oil leaks from it, I didnt really look too much into this because the same thing happened with my novarossi, its just strange because it was perfect last time and now all of a sudden its gone bad.

What im going to do tommorrow is a process of elimination, im going to check the carb then try new fuel lines, change fitting of tuned pipe, clean tuned pipe, try fresh fuel, check clutch, even try the fuel tank from my old buggy,and if after all this there is still a problem then its probaly the main bearing(or a carb problem). Another thing ive noticed is that the rubber boot on the slider has a hole in it but I think im right in assuming this is for keeping dirt out and not an air seal.

my money is on a broken clutch spring....lets start the bets at oh say 10bucks

yeh i broke a clutch spring one day and it wouldent stay still when i try to stop it, and it sucks trying to put those things on!![:@]

No its not that, Ive checked all that stuff, the obvious , thats why it is so strange, im starting to think its a fuel tank leak so in the morning ill give that a test.

There is your answer, it's the same problem 421Bs havewhen you run them higher than Idle they have to be richer than normal, then you brake and it cuts because it suddenly leans out because of the air leak on the front bearing.

Do you use ARO?

I'll BET if you change the front bearing this problem will go away.

clutch bell bearings...they're locked up

i had the same thing read this[link=http://www.rcuniverse.com/forum/m_2494813/anchors_2499051/mpage_1/key_/anchor/tm.htm#2499051]ClIcK On mE!!![/link]

, the problem was that it was runed to lean and it damaged the sleave and piston thats what os lold me but i always ran it realy rich and always perfect temps and they sayid its an obrasion.

My piston and sleeve are in perfect condition. I might have to order a new bearing . I think ill replace it with a novarossi one instead of an O.S one.

Alex, what u mean by ARO?

It could be your carb where you said there is a hole in. If that leaks than it can have adverse effects on a motor as well.

Hmmm, ill try the boot off my novarossi carb perhaps.

i looked at it before i sent it it was perfect

Well, ive tried everything except a new bearing and a new boot for the carb, the worst is if I order something and then it ends up not being the problem and ive waited for it for no reason. Its so strange it ran so well the weekend before.

After Run Oil.

Well if you strip the engine and look through it towards a light and you see this (below), then it's deffo the bearing. As for the carb boot, just look for rips in it, if theres none then thats fine.

See the gaps in the bearing seal?

Well I use 3in1 oil as after run oil . Thanks, ill check the bearing, there is a rip in the boot which I have temporarily repaired to test out. Ill try soon and see how it works.

Go for a new boot as repairs rarely solve anything.

the bearing would prolly leak, its prolly flooded the case and all motors will leak out of the bearing....

Dont panic, remove the back plate, put a thin but unbroken line of RTV Oxygen sensor safe silicon sealent around the flange replace back plate and relocktite the screws in place. Make sure your cooling head is on staight the screws may have backed off. Relocktite them also. Remove your carb and use RTY sealent around its flange. Make sure your pipe is sealing up with two springs not just one. Air leaks will mess up all engines idle and tuning and some more than others. I do this to all my engines cause you cant trust the factory and you cant trust o-rings. I have never had a bearing leak in such a new engine and I own 14 of them. Make sure you fully warm up the engine before you tune it and start you settings off rich and work your way to lean.