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  1. #1
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    Tuning, yes I know again.

    I just took a break from the office to go run my revo and have the folllowing question.

    I am getting the hang of tuning and I actually enjoy doing it.

    The question is this, if I am running around a track or doing continuous high speed runs it runs great.

    If I start playing around like hopping curbs and climbing things it loads up and i have to do do a speed run the clear it out. The low speed was perfect using the 4 second rule. The high speed was still a little rich but shifting fine when not loaded up. Any ideas what could cause that? Can a bad glow plug have anything to do with it?

    If starts fine. Should you just replace them every so many runs?

    Thanks,

  2. #2
    RC Turnbuckle Jr.
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    It's not the plug. When i stage up i have the same problem with it loading up, it's normal. The only real way "without leaning her out" to avoid that is to keep on the throttle in short burstes.
    Keep flex'in those forum keyboard muscles.

  3. #3
    RC Turnbuckle Jr. Snook Man's Avatar
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    Lean the LSN slightly. A 4 count is a little rich IMO. Tuned well it should not load up during low speed runs.
    No slipper/tall gearing/power = broken parts.

  4. #4
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    So can you do damage to your mill by running the low speed to lean like the high speed. What will happen if low is too lean? What are the signs? Heat, the way it runs, the way it shifts, etc.?

    Thanks

  5. #5
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    it will overheat or really hot, loss of smoke trail, high rpms, creeping forward from a stop, stuttering on launch, and it will scream like a cat with its tail on fire, but only for a little while, until it becomes damaged
    Never chase a skunk with a Revo!

  6. #6
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    Quote Originally Posted by Crent
    it will overheat, loss of smoke trail, stuttering on launch, and it will scream like a cat with its tail on fire, but only for a little while
    You mean only until it seezes.

  7. #7
    RC Turnbuckle Jr. Snook Man's Avatar
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    Quote Originally Posted by OffRoadPede
    So can you do damage to your mill by running the low speed to lean like the high speed.
    Sure it can hurt your engine. A 3 second count is not what I consider LEAN, it gets you close and then you can fine tune for the performance your looking for.
    No slipper/tall gearing/power = broken parts.

  8. #8
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    Thanks I will try 3 and tune from there.

  9. #9
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    Quote Originally Posted by OffRoadPede
    Thanks I will try 3 and tune from there.
    DUDE! It sounds to me that you are really close to getting that thing tuned just right. You are doing high speed runs, staying on that throttle and your temps are fine? Thats great. DO YOUR SELF A FAVOR. When you turn that LSN please please just turn that thing a hair at a time. I mean like 1/16th of a turn maybe a little less if thats possable. You will see the difference. I would wait until you have her up to temp and at about 1/2 tank before touching that thing. I'm sure you know that already but just thought I'd throw my 2 cents in.

  10. #10
    RC Turnbuckle Jr. fallonguy's Avatar
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    The LSN only comes into play when your are at idle or the throttle is almost closed once you open up the throttle then only the HSN is used untell you let off throttle.
    I wanted to put a really cool signature but I ran

  11. #11
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    Quote Originally Posted by fallonguy
    The LSN only comes into play when your are at idle or the throttle is almost closed once you open up the throttle then only the HSN is used untell you let off throttle.
    Then it was the HSN that was too rich or maybe both. I was wondering that myself. That is good to know about where in the power band each needle is used. That should help me a lot knowing that. I would have leaned out the HSN earlier if I knew that.

    I am just being precatious, I don't want to buy a new mill or motor yet. I just dumped a lot of money on this and I would like to get some use out of the mill that comes in it.

    Then it's time to upgrade. I think I am going to put something in there that really rips when this one crokes. I do not see doing the Traxxas replacement plan thing. Why would I want to go back with what came in it?

    Thanks all!

  12. #12
    RC Turnbuckle Jr. Snook Man's Avatar
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    If your truck was switching gears and running well on the top end, The HSN is fine (I would not touch it until needed)...The LSN is what controlls low end performance. Curb jumping, climbing and general putting around at slow speeds is controlled by the LSN setting.
    No slipper/tall gearing/power = broken parts.

  13. #13
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    Quote Originally Posted by Snook Man
    If your truck was switching gears and running well on the top end, The HSN is fine (I would not touch it until needed)...The LSN is what controlls low end performance. Curb jumping, climbing and general putting around at slow speeds is controlled by the LSN setting.
    I seem to be getting conflicting information here.

  14. #14
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    Quote Originally Posted by OffRoadPede
    I seem to be getting conflicting information here.
    I think your HSN is fine. OK what are your temps after you have warmed her up and blasted around the track doing your High speen runs? If she is responsive shifting fine, blue smoke, around 220-245 degrees then leave your HSN alone. I mean temps are not everything. And I'm sure alot of people will agree I just. Every motor is different and will run at different temps. Air temp, humidity (spelling) conditions of your surface area you run on will play a huge role in how your truck runs. I'm no expert I would have to say that I kinda know what I'm doing. I'm sure someone who is way more experienced then I will set you in the right direction. By the way I just used those temps as a guide.

  15. #15
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    a 4 count is WAY too rich, 3 is still a little itsy bitsy bit much, I kinda hang around a 2 1/2 count. Most engine manuals will actually say between a 2 and 3 second count, cause a 2 count is really getting kinda lean and you'll notice a loss of that puff of smoke when you take off
    REVO 3.3, LRP Z28, BUKU, RMV Speed 3 Auto clutch

  16. #16
    RC Turnbuckle Jr.
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    Quote Originally Posted by OffRoadPede
    The question is this, If I start playing around like hopping curbs and climbing things it loads up and i have to do do a speed run the clear it out.

    Thanks,
    Like i mentioned in post #2 it's normal for the carb to load up if your not consistently on the throttle. IMO your tune is probably fine. No need to lean it out just to get a jump and risk it overheating unless you like to constantly bring it in and check the temps.
    Keep flex'in those forum keyboard muscles.

  17. #17
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    3.3's should not load up from sitting, if you are in tune you should be able to bring it in and it should idle consistantly for 10 seconds and you should be able to instantly stab it with no hesitation.
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  18. #18
    RC Turnbuckle Jr.
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    Maybe there is a fine line from what i consider loading up, all of my 3.3's i have had to goose them before i get a true WOT launch "hence my version of loading up"...Others might not mind that but it has lost launches "out of the hole" for me in the past..
    Keep flex'in those forum keyboard muscles.

  19. #19
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    lean the lsn a tad, 1/16 and see if that helps
    nitro runs are endless with a revo

  20. #20
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    I get my perfomance close on the hsn with some smoke and no hesitation in high speed runs. I get the lsn within 3 to 31/2 seconds and then slowly bump it to the lean side until I get instant launch. If I have to lean the top after that I might richen the bottom back a little because you just took fuel away from the main needle. Usually if you go to lean on the lsn it will run on after a high speed run or want to walk away at idle. Once you get the lsn right your idle will also be good with no loading. It should really be able to idle for awhile with no load and take instant WOT.
    2009 Florida State Monster Truck Champion
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  21. #21
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    The weather is bad here. It was like 80 earlier and now like 45. Supposed to get way colder. I will tune on a better day, no fun driving in this kind of weather. Thanks for the input everyone.

  22. #22
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    Quote Originally Posted by racecontender
    lean the lsn a tad, 1/16 and see if that helps

    +1, if it does but not idle out enough turn your idle screw in 1/4 to a 1/2 till it picks up. Some times I think mine is loading up, but actually I did not have enough idle. If the idle adjustment does not idle it up, turn the idle back to where it was at and turn the lsn another 1/16 in untill it cleans up. Your first post, depending on the weather, my car does dang near exactly as yours. I just go blow it out on a straight away and go back to jumping curbs or whatever if I don't feel like tuning it...as always if my temp is satisfactory.

  23. #23
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    yea, with the symptoms your having its for sure a lsn issue
    nitro runs are endless with a revo

  24. #24
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    i have a question i am new to the nitro scene and im loving it but the tuning is getting me, im learning though but it seems that when i make a high speed pass when i release the throttle it revs up quite bad, i have tried richening the hsn but it still does it, ive richened it to the point where its so sluggish it will barely shift. could this be a lsn adjustment? or an idle adjustment im also have trouble getting a consistent idle, it always semms to go up and down while sitting still

  25. #25
    RC Turnbuckle Jr.
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    Quote Originally Posted by wreckless822
    i have a question i am new to the nitro scene and im loving it but the tuning is getting me, im learning though but it seems that when i make a high speed pass when i release the throttle it revs up quite bad, i have tried richening the hsn but it still does it, ive richened it to the point where its so sluggish it will barely shift. could this be a lsn adjustment? or an idle adjustment im also have trouble getting a consistent idle, it always semms to go up and down while sitting still
    Total symtoms of a possible air leak but first i would make sure the LSN 1-1/2 out and the HSN 4 out if it's 50 degrees+ and tune from there.

    Air leaks,
    There are so many things to check out, and im sure ill miss one. Check your fuel tank gasket and line, carb mount screw, back plate and ez-start, front bearings and anything else that could have blow by residue on it..

    People have described the mill sounding like chewbacca from starwars when you let off the throttle from a high speed pass when there is a air leak.
    Keep flex'in those forum keyboard muscles.

  26. #26
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    Yes, you have your LSN to lean, it should fall back to low rpm after throttle release on a high speed run.
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  27. #27
    RC Turnbuckle Jr. Snook Man's Avatar
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    Quote Originally Posted by wreckless822
    i have a question i am new to the nitro scene and im loving it but the tuning is getting me, im learning though but it seems that when i make a high speed pass when i release the throttle it revs up quite bad, i have tried richening the hsn but it still does it, ive richened it to the point where its so sluggish it will barely shift. could this be a lsn adjustment? or an idle adjustment im also have trouble getting a consistent idle, it always semms to go up and down while sitting still
    All the symptoms of a LSN that is too lean...
    No slipper/tall gearing/power = broken parts.

  28. #28
    RC Turnbuckle Jr.
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    almost always this is the case of all tuning problems it seems... the LSN being too lean...
    If you don't like Nitro, you don't like anything!

  29. #29
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    Not to hi-jack this thread but it is related. A heavy bog (loading up) when the throttle is held at 1/4 throttle....LSN or HSN related? I have read that at 1/4 throttle the HSN starts to take over, my thinking is it's a LSN problem as well, any idea's?
    Keep the greasy side down!

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