From JP-1 to JP-3= out of tune question.
#1
From JP-1 to JP-3= out of tune question.
I switched last week and was finally tuned properly. But once I put the JP-3 on I was way out of tune. I am still learning to tune properly. My question is do I deal only with the high end needle to retune or both. What happened was I was getting like 7-8 mins a tank and after installiung the JP-3 I barely had 5 minutes run time.
#3
Generally speaking you need to get the high end tuned close before really messing with the low speed. Remember that the fuel has to go through the high speed needle to get to the low speed so adjusting the high speed will also change the low speed.
Of course, if the thing won't even idle then some adjustment may need to be made to the low speed before you can even start on the high end.
Of course, if the thing won't even idle then some adjustment may need to be made to the low speed before you can even start on the high end.
#4
Like I said it was tuned great before the change. Really what I want is my runtime back, power is good idle is awsome. So try a couple hours lean on the high? I would rather not touch the low end if I dont have to cause it was a B to get right. This only my 3rd nitro mill, I recently added racing nitro along with my electric.
#5
Tech Champion
iTrader: (125)
You can try leaning the HSN a little , just watch so you don`t go too lean . Even being tuned great before , it doesn`t mean squat now that you have a totally different pipe on it . Retune it till it runs great with a smoke trail at normal operating temp. You most likely won`t get the same run times as you did with the JP1 .
#6
Tech Adept
iTrader: (8)
Like I said it was tuned great before the change. Really what I want is my runtime back, power is good idle is awsome. So try a couple hours lean on the high? I would rather not touch the low end if I dont have to cause it was a B to get right. This only my 3rd nitro mill, I recently added racing nitro along with my electric.
Start your engine and drive aggressively for about two minutes. Check your temp. with an infrared temp. gauge. Depending on who you ask but I would try to get my temp around 220-240. If you are below that range turn your high-side needle clockwise in small increments 1/16 to 1/8 of a turn at a time until you get to desired temp. Of course, if your temp is above desired range, turn high-side needle counter-clockwise in small increments.
After achieving the engine's proper operating temp. reduce the engine throttle to idle for about 15 seconds. Now pinch the fuel line with your fingers close to the carb. fuel inlet nipple while carefully listening to the engine rpm. If the engine dies immediately without an increase in rpm,the low-side needle is set too lean. If the rpm's increase dramatically and the engine dies, the setting is too rich. The ideal setting results in the rpm's increasing a slight amount (about 200 rpm's after pinching the fuel line before dying.
Yes I copied this out of a manual, only changing a few words around. Like I said before it may not be the best method but it's a starting point. Hope this helps.
#7
Different pipes will give different results. If it is not running too hot try leaning it down a bit. If you still don't get the mileage you have some decisions to make. First off try to determine if the new pipe is making more power and if so, has this improved your laptimes? If not, switch back to the old pipe. If so, do a little numbers crunching to determine if the new pipes faster laptimes are enough to make up for the increased number of stops.
#8
Well I have only ran 1 race day with it and didnt want to play with the tune till I had advice on it. Thanks for all the info, yes the powerband is much smoother with the JP-3 and temps are similar. Should doing that switch use more fuel? I thought I would get better mileage out of the 3 because it is a more versatile pipe. I want to try to get a few tanks through it before my next race and try leaning the high 2 hours and go from there. The reason I have had trouble tuning this mill I think is because it is modded, I thought that having that done was supposed to give better mileage and cooler temps "it does run much cooler than the maker says it should".
#10
when changing pipes i normally go back to factory settings and start from there
#13
Well I went and put a few tanks of fuel through it and I ended up leaning it total about 3 hours and it is much better. Bette runtime ans the JP-3 makes the power smoother all the way through, the Jp-1 was all off the line and died 3/4 of the way through. The mill is a SH 6port .28 And I sent it to a local guy, for my 1st race nitro mill it is just fine. I am getting a buggy at the end of the summer and I am going for my 1st high end mill and it will definetly be a .21. I wanted a truggy 1st as I was told to learn driving nitro on a truggy would be easier, I also race 10th scale electric and do very well with that.