Hey" Dogman

I just wanted to ask you for an update on your nemesis and the OFNA valve. I solved my half tank lean issue by changing to a smaller tank, the engine purred like a kitten but the run times I can no longer deal with, so I am switching back to the original tank an ordered the OFNA primer pump. Thanks for all your help..you are a great asset to this forum[8D]

Aw Thank you Soilwork your kind words are much apprieciated!!

That valve is still hanging in there doing its job!! I have converted afew people here locally and they love it, especially now that summer is here.. They dont have nearly as many flame-outs and it been over 100*f for the past 2 1/2 weeks. HOT!! Let me know when your valve shows I will show how to set it up. I think you will quite surprised how much you will lean both needles and it will purr like a kitten and idle for days!! I would like to find a more refined valve that doesn't cost more than $10. We'll see how it goes,,



Hey dustin since its summer how is your valve holding up in northern country??

BTW, That was a cool way to get my attention!!!

Thanks..!

I will let you know when it comes in!

No problem!!!

The ofna valve works wonders for me. Before the valve, the truck would barely idle at less than half a tank. Now shes rip roarin and ready to go.

such a simple solution, but so effective

Hey "dogman"
I have the ofna primer pump..so what I did was blow into it to see wich direction the air travels through it because that is the direction I want going to the fuel tank if I am correct. I know I have to retune it to compensate for the increase in pressure, I assume that the factory settings on the needle will be to rich, so my question is where would be a good starting point to set the needles. Thanks..![:-]

Hey soilwork,

Its been awhile but if memory servs you wil turn your needles in about three full rotations, but start with 2full rotations. Due to your climate you may need to be turned in that far. Dont forget the low speed needle, in fact once you get the valve installed tune your engine normally.


Once you get it tuned let us know how the new valve works out for you, it might worth having this vavle made without the primer bulb..

Good Luck, and if you get hung up, you know where I can be reached..

Thanks again...I am going to install the roto start, change the shock oil and then take it out and try to tune it. Thanks!

good idea!! Have fun!!

I've been noticing the half tank leaning issue a little on my GST running Werks Racing 30%, it's not too bad really I tuned it with the tank close to full and it idles good and has great off the line response.

But I do notice a good performance and temperature difference when the tank gets low, right now since the motor is still new I have it tuned pretty fat, with the tank full and a few hard full throttle runs it'll clock in around 190-200ish and with the tank low about 210-225ish and it launches and runs really hard when it's low.

From what I've read on this Ofna valve it looks like it solves the issue and balances the pressure enough? Also Dogman you have it mounted on the exhaust side of the tank instead of the fuel side, does the check valve in the primer help equalize the constant pressure in the tank or what? And I assume the priming abilities are not lost even though it's where it is?

Thanks guys!

dogman come down to phoenix and hit the tracks. the 1.5 hour drive is well worth it.

1.5 hours hah. I can make Phoenix in an hour flat

Arizonarevo, I could do the drive, there aren't really any big tracks here. The one at Hobby Town On Speedway is kinda small but they have changed it around alittle to get longer straights but it's still too "technical" What track are you talking about in pheonix? I would be interested...

Hey dStruct almost missed your post.

Yes the valve is mounted between the exhaust nipple(he said nipple) and the tank inlet, the function of the valve is to keep a steady pressure in the tank even when you let off the throttle. The fuel delivery system is an "open to the atmosephere" system so when you let off the throttle the exhaust pressure suddenly drops as does the pressure in the tank. Well this is not an issue when the tank is full but when its half full the air volume in the tank compresses more so it takes longer to recover the pressure needed to feed the carb quickly enough. So flame outs are common. The valve keeps pressure in the tank when you let off the throttle, its that simple!!! the primer function of the OFNA valve does not work in this application but it also does not seem to be in way either, and its cheaper than the Hyper Valve offered by perry pumps. Big bonus!!

Get the Valve you wont be disappointed!!


Soil Hows it going bud, get that beast tuned??? Let us know....

Lol you said nipple, huh huh huh (butthead voice). Seriously though, I just went out and purchased an Ofna OFN10166 (large fuel filter), and OFN10168 (primer pump/filter) yesterday, I'll post some pics once I have the time. Yeah I would think the pressure in the tank would be much like a hydraulic piston/cylinder vs. pneumatic.. Air isn't very dense.

So I mounted the filter on the middle of the rear shock tower with a zip tie (cause Dogman needs to machine me a bracket that would screw into those two screw holes in the rear shock tower, hint hint nudge nudge..), and the primer dealio I mounted on the front brake screw/post where my throttle return spring goes for a lack of a better place, but it twists slightly when I use the brakes..

I was thinking a good place to mount this primer would be the exhaust side handle/roll-bar, drill a hole to keep it from twisting around. Anyone know what size screw is used to mount the handle to the truck? Looks to be about a 3mm or so, I may run a tap through the hole.

Any ideas on better mounting locations?

dStruct Check my gallery for my location of check valve

Yeah that's where I got the idea, it's the best logical place to put it really, but I still have my handle on mine and zip tying the primer to the handle wasn't very secure, and it looked like crap.

I got the same Ofna filter and stuck it in the same place as you but it would be really slick to have a mounting plate of some sort that could bolt right to those 2 holes back there and hold the filter up off the shock tower maybe 1/2" ?

As for the primer is it bolted down to anything? I couldn't see clearly if it was, even a simple little "L" bracket that could bolt directly onto the exhaust screw (the one holding the 2-pieces of the chamber together) I'm just wanting to screw the plastic bracket down to something.

Anyways, let me know if you're willing to machine something, and/or *if* you can machine something, I'll paypal you for it. [8D]

*edit* Oh and one more thing, I saw in your gallery you're running a Nova cooling head, do you really notice a difference with it, can you tune leaner because of the better cooling? Nova claims "Up To 40% Reduction In Temperature"

Thanks.

Hey I sent you a PM with some tuning questions, hit me up if you get a minute. [8D]

Where do you get the valve from?

I called around locally and just happened to find it, but if no one in your area stocks Ofna you could definitely find it online. The Ofna part# is OFN10168 for the primer pump w/ filter, and OFN10166 for the large fuel filter. I copied Dogman and got both and actually just ran them this evening for the first time, and WOW let me just say it made a noticeable difference in my tuning. You honestly can't tell if the tank is full or empty without looking at it now, as for getting my truck dialed in, I have it close but my low end is still not right.. Also while you're ordering if you don't have some already you might want to invest in a foot or two of fuel line. You should be able to make due with the stock tubing but it doesn't leave much room for error..

Let me know how it goes, you shouldn't have any trouble finding the parts.

Thanks.

Try this http://www2.towerhobbies.com/cgi-bin...=OFNG1035&S1=O OOPS Blew that !! Anyway do a Tower search for Ofna Filter. It will be there ....... sorry

Hey fellas, Actually I use a racers edge fuel filter on my rear shock tower(looks just like Ofna's works just as well) I got my Ofna Primer filter from Tower Hobbies, online. Here is the link to the [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXEYG3&P=7]Ofna fuel filter checkvalve[/link]

You will have to retune your low end also about as much as your high speed needle. But start with highspeed needle then work on the low speed needle take your time, and you will get it..

Good luck and keep us all posted on how it goes..

I was planning on taking the Nemesis out for fourth of July to tune it with the check valve installed, but while I had the engine out to install the roto start, I decided to check the clutch shoes and found a broken clutch spring. It looks like a coulpe of more days before I can try the check valve.

Good catch Soil that would have caused a problem later... Let us know you do, when you get it movin'