reflexsa

Hi there,
I have a revo 2.5r and the manual says only use 10% or 20% fuel and it says if you broke in on a specific fuel only run that fuel. Where I live only 16% and 25% is availible. Why does the manual say you shouldnt switch fuels and can I run 25%. Hope it wont mess anything up.

Any advice welcome

Quickywd01

My Feedback: (3)

You should be fine runing 25% just tune the engine. Traxxas fuel might say 20% on it but it really isn't 20%, its more like 14%. If you want to buy traxxas top fuel but don't like the price go check out S&W fuel. They make a new fuel called T-blend which is fuel that is exactly like top fuel but with a lower price. I just buy s&w pro car fuel 20%.

125cchyperman

Either one of those nitro percentages is fine to run. You can switch fuels if you so choose, but you will have to set all the needles back to the original setting and go from there. If you have any more wustions just get back.

ScRacing

I beleave you can order fule? And you can run eather of those, but when you switch fules you have to rebrake in the engine for a couple tanks. You don't have to be as rigerous as the first brake in but you should just go wide open in a race after switching eather.

rawkfist2

You can run up nitro percentge but never go back down.

beelzebubishere

My Feedback: (1)

More wife's tale and juvenile BS......use any fuel you want, just tune for it...re-break in the engine.....where do these kids come from?
WRONG.....just RE-TUNE.....I know neither of you 2 can spell....but can you READ!

125cchyperman

When switching fuel you do not have to re break in the engine. All you have to do is retune, that involved setting the needles back to the original setting and seeing how that particular fuel runs and then tune for perofrmance. There is no rebreaking in the engine involved. You can also go from higher nitro percentages and go down but your engine sometimes may not like it as you will have droped some compression. but you can always take a shim out and thats even if thats needed. Sometimes it is but most of the times it is not. You can switch fuels whenever you want to as I have switched fuel like underware to see what fuels I like. There are fuels that I did not like at all like Blue thunder and several fuels that I have come to like. Like trinity, O'Donell and Phantom fuel.

I have switched from lower nitro contents to higher and back down to lower nitro contents and you may run into some troubles but nothing that a shim or two and a little retuning wont handle.

BAMF90

My Feedback: (1)

You can go back down, just make sure to retune. I am using O'Donnels 20%, and it's AWESOME. It is so much better then Top Fuel. I have about 1/2 - 3/4 of a gallon of O'Donnel 30% that I'm going to try soon, but all I have to do is watch the temps, and retune.

ScRacing

Well hte traxxas engine manual says that you should be easy on the engine when switching to a higher nitro percentage, and obviosly you will have to retune, thats the same diference as going from 1 mile above see level and then to 300 feet above it. Any one who has ever rode a dirt bike in california and then rode it at a high elevation would know. And i never switch fules, i use odonells 30% with 8% caster oil in my sirio 23, and it works great. There is no reason for me to switch.

It may work for you, but i have no idea what engine you are runing and what your longest engine life may be, for all i know it could be 1 gallon is the record for you, or it could be 127, but i don't know. All i am saying is that thats what the engine manual sigests and it works for me so why not, cuase im sure it won't hert your engine. And the reason why i say "re brake in" Is i mean take it easy for a bit, check the engine temps every few minets and don't fry your engine, all it takes is 30 seconds to lean and to hot and there goes your $100-$300 mill, so you might as well do things as sparingly as posible.


And reflexsa, i would see wich fule has more oil in it, odds are it is the one wiht 16% nitro, so since you are new to the hobbey may be better for you because your engien will last longer and it should be easyer to tune. But it goes both ways, id say brake the engine in on the 16, then try some 25 and see what the diferences are, just be prepaired to tune and do things carefully! And good luck!

125cchyperman

The reason why I switched so much is when your racing I liked to explorer to see what engine and what fuel and nitro percentages worked best for me. I have several engine that have lasted over 6 gallons and are still going extremely strong. I still have the original engine that I started with which is just about 7 years old and still runs like the day it started. It's a pro .15 that came with the original t-maxx not these newer t-maxx's and revo's and such.

But anyways I switched not because I was having problems with the fuels (other then blue thunder) but because I wanted to find the best race fuel. I settled on Phantom racing fuel (30%) with the .12cvr. But once again I did this as a racer and the need to get an edge on others as our local track was filled with great drivers. Believe me thw owner of the LHS is sponsered by team associated and he driver's and he is almost unbeatble.

But anyways if you go to easy on it by richening it up a lot then you can put undo stress on the crank and or the con rod and do damage. Just set the needles rich and go from there.

But Now since I no longer race I no longer switch fuel and just stay with O'Donnel. But I do know what you need to do with adjustments when going from sea level to much higher heights. We race in another fomr of racing and have to compenstae for things regularly like ambient temp, humidity gearing and others. Did you know with larger 2 strokes if you put a tooth onto the rear sprocket your supposed to go to a larger needle or use a larger jet. So something that we have learned though mistakes and such on larger 2 stroke engine. But I do know what I am talking about and am aware of eveything that needs to be done.