offroadfury

I had an extra Cen stock 75cc tank and thought about adding it to my truck and was trying to figure out the best way of doing it and this is what I came up with in the photos below. I was getting about 8-9 minutes with one tank and to my surprise when I added the second tank today. I went out with a stop watch just to see what the time was with 2 75cc tanks. I still cannot figure this out. I got 26 minutes with both tanks. I figured I was only going to double my time. So where did the other 7 minutes come from. I am certainly not complaining about it but this seems really odd to me. And for the most part I was running full throttle. Any ideas???

dustin7837

My Feedback: (1)

26 minutes...
maybe since you were trying out your new tanks you were more concious about filling them up all the way?
Or maybe it has something to do with that fuel in line being pressed right upgainst the cooling head. The fuel could have been vaporizing before the carba dn running the engine lean. Did you take a temp reading while running it??


If you are looking for a nice neat way to install a bigger tank, try azzmans tank mod. He even made a nice little tutorial.

http://www.rcuniverse.com/forum/m_31...tm.htm#3197224

Looks cool with 2 tanks though [8D]

offroadfury

My temp was same as always 237 to 245

azzman

First off I would go with the OFNA tank mod (see my tutorial!!) as I wouldnt want fuel spilling into my radio box as per your setup. Also the whole thing will look a lot tidier and you wont have two tanks to fill up, the OFNA is 125cc so while not as much as 2 stock, still gives a heap more. As for the extra extra run time, who knows must be a liitle user error in the filling/timing, plus theres more fuel line which will add a little more, plus filling the tanks more like dustin said...[:-]

dustin7837

My Feedback: (1)

hehe...[>:]

I was reading this thread and I thought to myself. "Hey, I've got a spare genesis tank sitting here... Would it fit one of my funfactors...?"

Of course it would

I just used the same mount points as the ofna tank, and just made a mount with a piece of a metal coathanger
It's not much heavier than the ofna tank, but I havent tried it full of fuel yet.

craigb

WOW Dustin! Thats one HUGE tank[8D] do be carefull though mate that tank will weigh alot when its full... I can see your clutch going red in the face
Holy 60min+ runtimes [8D]

craigb

hard to say really... runtimes can changed by anything from weather, surface, driving style. also the flow of fuel to the engine slows down as the tanks empty (ever heard of half tank leaning[:'(]) as you have added another tank this leaning wont happen as quick, this will effect the run time too in theory.

poor judgement

whoa! speechless!

tank... big.... hell... ur not kidding!

aye the weight - with 2 tanks, u have of course double the weight in there. so run times wouldnt quite double with identical comparisons. ur extra runtime is either a lot more fuel than u measured, user error on measurements or... and from experience i reckon this is it - there is some leaning going on there. i always switch back to a single tank when mine starts to mess me around with the tuning, and 9 times out of 10 it sorts it out. sometimes it runs fine tho.

all im saying is that if ur measurements are ok, then its a leaning issue for sure and ur motor could have its life shortened. those temp gauges are sometimes pretty inaccurate, do u have any way of checking it against something else just to be safe?