mr invizable

hi all, im new here, so let me start off by saying "nice place you got here"!!

now for my big problems:
i gotta be honest, i jumped in a bit at the deep end, with my first nitro truck being a savage .25 rtr
since i got it, its been nothing but trouble, with the manufacturers over-tightening screws etc.

But now, i have 2 problems that are real mutha's

1) my picco .26 is spitting fuel from around the glow plug, i have changed this several times for all different sizes, and heats, but they all give the same result. I was wondering would a nice shiny new head sort this?

2)i have a 3-speed gearbox fitted, its fine going up through the gears, but gets stuck in 3rd even when i brake, it still stays in 3rd and screams at a very high pitch. why does it do that and how can i stop it?

a few biggies to kick off my account i know, but i am at the point where i wanna break the thing[:@]
all help will be greatly appreciated
vizzy

PSG-1

I'd definately check your clutch shoes and upgrade to aluminum ones if you're using the stock ones. The stock ones aren't really made for that kind of power and could cause it to not be shifting right. "it stays in third and screams" that confuses me a little bit... what do you mean by screams? Is it revving really really high like it's still getting gas? Might want to check the throttle linkage for that... upgrade to the ofna throttle linkage mod which makes a huge difference for consistancy in throttle/braking.

As for the spitting fuel from the glow plug... I don't know too much about that. I guess the first thing to say is make sure you have the washer on the glow plug there... might cause it to leak fuel out the glow plug. That's really the only thing i can think of that would cause fuel to spit out where the glow plug is. A new head would probably fix it but not quite sure. I'm assuming it's running funny and is hard to tune with it spitting fuel out of the glow plug so be careful.

DaveG55

The spitting fuel problem could be stripped threads in the glow plug hole. Also, you HAVE to use the copper washer at the glow plug and it must be cupped side down, like this ^.
The 3rd gear thing has me confused too. It would seem to me that if it were stuck "in" 3rd that the truck would be a dog off the line, real poor take off because of the high gearing. If the engine is screaming then it sounds more like it's caught between gears or somehing. I don't know enough about that transmission to help more.
Good luck.
Oh, and welcome to the board.

PSG-1

Yeah dave that's what was confusing me too... if you slow down and it's stuck in third then it shouldn't be screaming.

mr invizable

yes, exactly like that

how would i fix this, is it a new head or just a simple fix-it job?

thanks for your very helpful, and very quick replies all, at this rate my sav will be back on the road very soon indeed!!

PSG-1

I don't quite know if you can rethread a head as it might mess with the diameter of the hole and cause the glow plug to not seat properly. I'd say get a new head.

spareanychange

may sound stupid, but you are using the copper washers that come with the plugs yer? if so, then you have probebly stripped the thread on the head.

DaveG55

Stripped threads = new head.
Check e-bay, people sometimes part out new engines and you can get parts for cheap - well, sometimes.

dirtdemon8989

um I think these guys are covering the head thing so I think with the 3 speed tranny with that much power one of the gears inside has been stripped or the is debri and maybe some dirt in there I would take the tranny out and if you know how take it a part clean it then check every tooth on the gears and if it still doesnt work then I would go to your local hooby shop or ask hpi hope this helped but this is just wat I think so dont get mad if it doesnt work

-SomeGuy-

Sounds to me like you need to change that glow plug metal disk thats between the head and the crank case.I got the picco .27 and never had that problem.Maybe you had dirt in that area when you were changing the plug and that grinded the threads,make sure its clean next time.

As for the gearing problem well that sounds like your throttle is getting stuck, the gears staying stuck in 3rd wouldnt make your engine rev so high.Test it while the truck is not running, make sure that your servo is bringing back the throttle arm when you apply brakes.Maybe the return sping is to weak or maybe its screwed on to tight (on the servo) you might want to look at a stronger spring (stock is black and srtonger one is copper colored) you should have gotten one with the 25 rtr i know i did.

Good luck...

mr invizable

WOW!! i'm loving this forum, you all answer so quickly, and you all seem to know much more than other forums i have visited, i wont mention which.

well thanks a lot to all of you, i have plenty to go on there so i will start work on thje truck shortly and i will let you know how i get on, many thanks again
tom

dirtdemon8989

ya keep us posted for sure we always like to know if we helped haha well good luck with it and I hope we all helped in some way

fxrs

These trucks use a centrifical clutch and when you let off the throttle
the clutch should disengage and coast to a stop and idle or when you brake
and come to a stop. When you give it throttle the clutch engages and off you go.
The screeming as you call it is the engine deaccelerating as the truck slows down.
The reason you hear this and its happening is because your clutch springs
are weak or undersize or beat. With springs not doing there job clutch
stays engaged untill truck is almost stopped. It does this at higher
RPM's/speed but as speed and rpm's decrease clutch will finally disengage.
I had the same problem with my 11 year old sons savage and going
to a 1.1 mm spring fixed that problem on his savage.

Hpi_mt2

Hi, I have the same engine as you and a couple of days ago I stripped the head insert to my picco too http://www2.towerhobbies.com/cgi-bin...?&I=LXFLL4&P=7 That is the head insert its for a wasp .26 but the picco and the wasp are basically the same engines.