Switched gasses now it runs like $hit! what to do??

[Sledneck01]

Ok i have a 2.5 maxx. My girlfreind got me a starter pack when i got it which had trinity Monster fuel (pink) 20%. I broke my truck in with that. Got breaking done and it ran sweet. thing was fast as hell. Well I whent through the whole liter. Then I had 20% traxxas Top Fuel. I put that in and ran good for about 15 seconds prolly still had alittle pink gas in the lines then it must have gotten the blue from the new tank and then just started running like hell! wouldn't even get going fast enough for second gear and sounded wierd to. I put in a new glow plug and put the needles back to factory, and it still ran like crap. Well the guy at the hobbie shop said you kinda have to break it in again when you switch fuels. but after about 2 or 3 tanks it was getting alittle better every once in awhile it would get going into second but then slow down again. *** is the deal?? I also cleaned the air filter and everything. Anyone have any ideas??

[JoeMAXX]

It is true everytime you switch fuels you have to go thru a break-in again. Try to richen you LSN by a 1/8 turn counter clockwise to start and if it still stalling/running slow richen another 1/8.

After you get it running right again at low speeds/RPM then go back and adjust your HSN for speed and power.

This might help.

[R-MAXX]

i have never experienced that problem before.I use Traxxas top fuel 20% and Trinity Monster HP 20% every other tank and never had any problems..both fuels run great in my 2.5 maxx!!!

i even switched to O' donnels 20% without engine problems!!!

IF you broke the truck in with 20% then you really shouldnt have problems using different 20% fuels....especially Top Fuel And Monster HP...both great fuels for 2.5 Maxx

i think Top Fuel makes the 2.5 run a little cooler....just a little!!!;)

[fezzy]

You don't have to do another COMPLETE break in, Only say a couple of tanks....

This is what I always do, Re-set your needles to factory break in settings, run 1/2 tank at idle, stall the engine, let it cool, re-fill the tank and then start it and drive it round at 1/4-1/2 throttle, When thats gone I usually spend 1/4-1/2 tank going hard on it and then with the rest of the tank tune for performance again.

It does get a little annoying changing fuels, But sometimes its worth it if your going to a better fuel.

[TraxMaxST]

Try switching back to Trinity fuel and see if it runs better. If it does, just stick with the Trinity and give the Traxxas fuel to someone who runs that.

[Sledneck01]

Well I was thinking of doing that I am gonna run it for a few more tanks to see if it clears up and also adjust the needles to see if that does anything. if not i am going back to the trinity fuel!

[salohcin8604]

I know what you mean. I tried switching fuels once and it screwed me up. You really have to rebreak in your engine.

[BIGBADBOWTIE]

You do not re-break in an engine when changing fuels.
The process of breaking in an engine is there so that you set a NEW piston and sleeve to run with each ather. Your knocking off any burrs/flaws from the factory and basicly "setting" the piston to the sleeve. When changing fuels you are not doing this all over again... you are just doing that ...changing fuels. All you need to do is adjust the carb so that it works with the new fuel.

Each fuel has different oil/nitro/methanol mixtures.
Thats why when changing fuels it needs to be tuned again.

If your trying to re-break in an engine your justing waisting fuel.

Tune it and let it rip!!


Sled..... the reason why its not running well is probbaly because the Traxxas Top Fuel has more oil content. You may need to lean her out a little to get it to run right.

[salohcin8604]

Not necessarily bowtie. But your right you don not re breakin but it does help to run a tank of two easier when you first switch. It helps the engine make the transition.

[Madmann135]

I switch fuels all the time and I suggest that you try this out when you change fuels in the T-Maxx.
-Turn it to one fourth to one half out.
-First tank on an stand would be OK if you want.
-Idle to low speed a half a tank, Bliping only
-the other half Idle to low-med speeds
-the second tank Idle to Mid speeds
-Same for the first half of the third tank then you can tune it for power.

This could take up to an hour depending on how fast you want it done

[BIGBADBOWTIE]

I switch fuels all the time also....I have ran as many as 3 fuels in one day. I never run them in....I fire it up TUNE it and let it go.
On one of my engines I have 6 gallons on it and I have ran 5+ different fuels through it and all I have ever done is retune.

Its no different then in my 355 roller motor thats in my camaro. On race day I run 104 octane..... on street driven days I run 93.
I don't "break it in" everytime I change fuel types.

Do what you want but running all that fuel through it is a big waste in my opinion. Im going to send a few manufacturers a note and ask them there opinion.

Ray

[poopie]

BOWTIE hit it right on the head. You do not need to re-break in the engine. Traxxas Top Fuel has 3% of 4% more oil which is making your engine run slower. Lean it out some and it should solve all your problems. I can go from Blue Thunder to Sidewinder Pro Blend with out any problems. All I have to do is richen it when I go from Blue Thunder to Sidewinder and lean it when I go from Sidewinder to Blue Thunder.

[JoeMAXX]

Originally posted by salohcin8604
Not necessarily bowtie. But your right you don not re breakin but it does help to run a tank of two easier when you first switch. It helps the engine make the transition.

That is like a break in of the engine not trying to argue here but when you switch fuels the manufactures suggest that you allow the engine to adjust to the new fuel.

http://www.rccaraction.com/rn/articles/nitro_fuel.asp

A thing by our buddy Steve Pond who we all look up to for advice in our RC toys Read the whole thing our RC buddy suggests a second breakin period.

Yes and no. Yes, you can change the percentage of nitro in your fuel safely, but you must not make a change and run the engine hard right away. Every engine undergoes a process called “hysteresis.” In hysteresis, the engine components slowly acclimate to the specific cylinder pressure and engine temperature that result from burning a particular type and blend of fuel. A change in fuel changes the whole picture for the engine. An engine that is accustomed to a certain amount of expansion using its usual fuel might now have to cope with increased cylinder pressures and the additional expansion caused by higher temperatures. Simply pouring a new fuel into the tank and “letting 'er rip” places undue stress on the engine components.

If you use a different blend of fuel, your engine has to go through a second “break-in.” Run the fuel mixture slightly rich and ease into the throttle for a few tanks before you nail it. If you fail to follow this procedure, your engine will still survive 99 percent of the time, but it will last longer and run stronger if you make a gradual change to a new fuel. There is also a break-in period during which using less nitro presents a new set of parameters for the engine.



Few more thoughts

JoeMAXX

[Sledneck01]

I GOT IT! WAAAA WHOOO! I did alittle tuning and it rips now! thanks guys! except now I have to try an not break so many things! lol In three days I have broken fron bulkheads, a-arm, bumper, front bumbers and bulkhead braces! and one prong in the easy start busted off! Ez-start is comeing out though, I hate it, when it it cold it never wants to turn the engine over.