Hi guys, well i thought the day would never come, but..... I finally got my GST run in! No my controls haven't arrived yet [&o] but my boyfriend brought a cheap nitro off ebay that just happened to come with a 3 channel radio controller, so guess who stole his radio controls

I ordered an ofna value and that arrived on monday, but since putting it on, the truck seems harder to start, is this normal? Usually I find it a bit difficult to get it running first up, but once that first initial start is over and it's warmed up, usually it only takes one pull and off it goes again. But now with the ofna value, it takes 4 or 5 pulls.

Next thing is, I haven't touched any tuning on it as yet, don't want to stuff it up basically [&:] But I guess since it is run in now, I'll have to adjust something now, LOL. I know that I'm suppose to lean it out a bit, everyone keeps wanting to lean my truck and i have to protest loudly to stop them [&:] I keep telling them it's still running in, leave it alone. But my excuse is gone now, it is run in now.

Apart from it basically cutting out now and then, it runs really well. It iddles well just maybe a bit high though. The main thing is the cutting out or stalling or whatever you call it i read somewhere that stalling and cutting out is quite normal during the run in period, so i have just put up with it, but obviously I don't want to keep walking after it every time it dies for no good reason. This is where I'm guessing it's all in the tuning.

So come on guys, give me some advice on the tuning pleaseeeeee, which neddles to touch and which to leave alone, and in which order too

Oh I brought a temp gun since i live in a really hot humid climate, thought it might be a good idea to keep an eye on the temp so that I don't over heat it

Hey HarleyGal,
Glad to here you have her run in.

When you installed the Ofna Valve you effectively changed the tune of engine dramatically.

Without the valve the fuel system is what is called an open fuel system. In other words there and a clear path to the outside atmosphere via the pressure tube that goes from the Exhaust nipple to the tank(there is no mechanical obstruction/valve). So when the engine was running the fuel system relied exhaust pressure to pressurize the tank/fuel system. Well when the engine is at idle the tank has decent pressure, then when you stab the throttle the exhaust pressure rises rapidly so help feed the extra fuel to the carb. But when you let off the throttle the pressure in the tank drops suddenly so it wont flood the engine. Well, thats ok on a system with smaller fuel tanks but when you have tanks as large as the 220cc onthe Genesis series truck you have more space in the tank to pressurize so this effect does not work as fast and when the tank is half full it takes much longer to pressurize the half full tank and you suffer from the now infamous Half tank lean issue know to plague these open fuel systems on larger tanks.

You can find the thread here on RCU that discussed this problem in depth by searching for [link=http://www.rcuniverse.com/forum/m_4462148/anchors_4462148/mpage_1/key_half%252Ctank%252Cleaning%252Cissue/anchor/tm.htm#4462148]"Fuel tank/motor issues.... Again..."[/link]

Ok, now after long deliberation on this problem I realized the real problem was the lack of stable pressure in a tank this size. I then theorized in the thread that what is needed is a checkvalve of some sort to hold pressure in the tank longer after you let off the throttle. The search was on to find a valve that worked, and I literally tested a dozen or so valves!! In fact I almost gave when I ran acrossed the Ofna Primer/Filter, and I thought what the heck try one more time and ordered it. Well, it wasn't a total success at first. I could not get a good tune for the life of me. Until it hit me I am adding ALOT of pressure to the tank and I now need to control that pressure better by leaning out the needles Drastically, Starting with the high side first. So I started the engine and started turning the High Side Needle in until it started to run better and did not seem to load up(flood) as much. Then I went to the Low Side to control the idle mixture until it idled well and would accellerate quickly

The point is now that the valve is on you will need to lean high side Needle then the low side needles quite a bit. It will vary how much depending on your region! You will have to find that sweetspot yourself, but its there!! Just be patient and only turn the needles 1 hr increments. Dont be surprised if you end up turning the high side needle more than 1 complete revolution. I live in the American Southwest(Sonoran Desert) very dry and very hot in the sumer(over 105*f for more that 30 days in a row!!) So I had turned mine 2-2.5 complete revolutions to find the sweetspot.

Now I know that was more than you asked for, but you got it!!

I hope it helps!!

Contact me as soon as you read this to let know if its clear enough for ya

Thanks heaps dogman, it sounds all good in theory and I understand what you are saying, so now I'll just have to put it into practise, then I'll let you know how I went. I was nodding when reading your reply, yes I flooded the truck trying to start it when the value went on, cause I was use to how much I had to prime it before the value, but with the value, it obviously didn't need anywhere near as much priming. And yes, since the value the idle is a lot higher, wasn't that high prior to the value. So can i ask about the stalling issue, (before and after value installation) is that just cause it is running really rich and flooding at the moment?

Thanks heaps for your help Dogman

Yes, thats exactly why it would stall! Good, glad you understood it!! Have fun putting it to practice, I'm going to bed now, Night!

And good luck!

As always feel free to ask!!

Ok so I'm going to try the tuning later on today, but I have another question that is a little off track It is rather hard in my area of Australia to get hold of parts for the GST, so I'm thinking I might start to stock up on a few things that may break or wear out. I know it depends how you use your truck and I guess on the individual truck itself as to what will actually break etc, but can anyone suggest any parts that are more likely to let go, that might be worth having on hand? No matter what you have on hand, you'll probably need something else too, but you know, it just might make things easier for me. I'm not into huge jumps or anything yet, just mainly back yard bashing and once a week at a small private track. Any suggestion will be highly appreciated