Help with OS 21 VZB V-Spec
 

Can anyone help on adjusting my engine? How do you have your enigine tuned? How many turns out do you have your settings? I had it running great then next time around it would not start? The idle screw I 1 turn in from flush with the housing like the manual says. The mixture screw I have 2-3 turns out. Is this close?

Thanks

RE: Help with OS 21 VZB V-Spec
 

I would say it is pretty close since it ran before. Make sure you have a working glow plug. I would say try to get someone who has experience like "mayhem maniac" to help you. It would be almost impossible to explain how to tune your engine. Although there are some real good articles on the web. Search for nitro engine tuning and read them. But your best bet is to take it to your local track and get some help, and as time goes on you will get more experience and your tuning skills will improve...

RE: Help with OS 21 VZB V-Spec
 

Roland. Thanks for your help. I messed with the previous settings. It seems that there are no tracks in my area. I have been searching for some RC people in the area with not much luck so far. I guess my search continues. thx.

RE: Help with OS 21 VZB V-Spec
 

I also have a vspec. love the thing. Was there a big difference in temp or time of day compared to the last time you ran and it was fine ? I find if its later in the day or the weather is starting to get colder that i run a little leaner. but like the post before mine said check your plug. ofter the break in process will ruin your plug.

RE: Help with OS 21 VZB V-Spec
 

Hey Thx for your help. No the plug is new I changed it. It was a little later in the day. Ths car is not new and either is the engine. I was given all this buggy stuff from a friend who did not want it and the MP 7.5 had this OS 21 in it so it has been broken in. I guess it is just going to take more time to educate myself on how all htis works.

RE: Help with OS 21 VZB V-Spec
 

Giving you the benefit of the doubt, that your plug and engine are in working order and already broken in you either:

1) Due to weather (or your changes), you have caused an overly rich condition.

Remove your glow plug, start the engine a couple times to remove the unburnt fuel. Re-install the glow plug, and lean the high speed needle slightly. Repeat, until engine starts.

Also, an overly rich low speed needle can cause the engine not to idle, so the rich condition you are experiencing may require you to increase your idle adjustment.

2) Your engine is not receiving fuel from the tank.

This could be due to an air leak or clogged fuel filter. To check this, watch an air bubble in your fuel line to make sure that as you start the engine, it is being sucked toward the carb.

RE: Help with OS 21 VZB V-Spec
 

Thanks guys, Does this sound right? Mixture control valve - 1 turn in from flush with the carb body, Needle valve 2 1\2 turns out, Metering needle flush with the carb body and this is the one I should play with to get it idling properly? What about the throttle stop screw? anyone now how many turns out it should be? The manual says nothing about that one???

Thanks,

RE: Help with OS 21 VZB V-Spec
 

Er, ok, throttle stop screw is probably idle screw. This is what you want to look at for the idle. Pop off the filter and look into the carb, if when you turn this screw IN, the carb opens very slightly, then this is the idle. You want it set to about 1mm gap, and leave it, use throttle trim to play with it after that.

Mixture control valve, 1 turn in from flush...hmmm, I don't know this engine, but that sounds lean to me, try half a turn in from flush to start with, this is not a needle, it only affects the point at which the carburettor is supplied with a 'boost' of extra fuel. Once you get the two needles set correctly, you can play around with this (always bearing in mind that adjusting this, requires an equal and opposite adjustment of the low end needle). Set the low end and high end needles to break in settings, then starting with the low end, wind it in in 1/8th increments, until the engine accelerates smoothly, now, with that one set, start on the high end needle, same thing, keep winding it in until there is no bogging, but always make sure that you have a good trail of smoke from the exhaust, overleaning it will make it overheat. Ultimately destroying the engine...good luck...

RE: Help with OS 21 VZB V-Spec
 

The mid is supposed to be 1 turn in from factory(I found it ran better backed off 1/4 turn note you must compinsate by making a 1/4 turn the opposit way on the lsn).My settings are at 2 3/4 out on the HSN, 1/4 turn out from flush on the lsn.This is running with sidewinder 30% with a sportwerks 053 pipe mugen 1.0 springs and ofna carbon shoes with the blue carb restrictor and extra head shim installed.I pulled it off the track after a 45 minute main and it was running 216 so there is more than likely room for me to lean out.

RE: Help with OS 21 VZB V-Spec
 

This was meant as a joke I hope.

Mayhem maniac has absolutely no experience, so it would be very unwise to get him to help anyone.

RE: Help with OS 21 VZB V-Spec
 

No! Don't forget Rustler08/mayhem maniac is the resident 'forum genius'. He knows everything about everything, or at least he believes he does.

Sorry MM, but you will NEVER live that one down...not as long as I'm around...;)

RE: Help with OS 21 VZB V-Spec
 

Check the high speed needle.Turn it out about 1/10th of a turn.Mine worked great for a few days and without doing anything one day it would not deliver fuel to the carb.So give it a try.Mine was also dying after running for 10-20secs.

RE: Help with OS 21 VZB V-Spec
 

NEEDLE SETTINGS:
High Speed - (see pg 17 of manual) 3 turns out from fully closed
Metering Needle - (see pg 22 of manual) Head of screw is flush with
ball link body
Mixture Control Valve - (see pg 22 of manual) Head of screw is 1 full
turn in from flush with carb body

the whole manual:
http://www.osengines.com/manuals/21vzb-vspec-manual.pdf

RE: Help with OS 21 VZB V-Spec
 

Thanks everyone for your help. I have set it at the manual settings but it was still giving me problems to start.

I played with the stop idle screw and that help. It does not have a good starting point setting? I can juts play with it till I find the sweet spot?

RE: Help with OS 21 VZB V-Spec
 

is your glow igniter charched properly ?

RE: Help with OS 21 VZB V-Spec
 

Ellis, yes it should be. I charged it the night before using it and the glow plug lights up. I think I will reset all and try again as I think I may have a better understanding of how it all works. Man this stuff takes patience......

Thanks

RE: Help with OS 21 VZB V-Spec
 

Engrose, never underestimate the knoweledge of the all might rustler. he is now the proud owner of a mayhem. A very difficult buggy to assemble.

RE: Help with OS 21 VZB V-Spec
 

Yes you're right. If anybody in a few and precise words can explain how to tune a nitroengine in the best possible way, then it would of course be "the forum genius", "the almighty" and "allknowing" rustler/mayhem maniac.....

The knowledge one can obtain from having an used rtr-buggy for one day is without any kind of limits:D