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Savage X4.6 tuning problem

Discussion in 'Nitro Engines' started by Tommi_82, Jun 6, 2018.

  1. Tommi_82

    Tommi_82 Member

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    Hi!

    And first of all, sorry for my bad english.
    I'm kind a noobie with these, so maybe this is stubid question.

    I buyed my Savage about a year ago, last summer goes pretty well and all worked just line meant to be.

    But in this summer, just feels that i don't get all of power out of engine.
    I tried to tune hsp, and just when car starts to move like it meant to be, engine heat goes way too high, about 150-170C
    Engine sounds pretty normal, and gives outnice white smoke, nothing doest refers that engine is too lean.
    When i loose HSP to get heat about to 120C, it just don't give out any power.
    I'm using pretty much stock setup, only difference is robinson racing clutch bell and spur gear and HPI high performance clutch.
    My heat meter is HPI ultimate tuning screwdriver

    What I'm doing wrong?
     
  2. olds97_lss

    olds97_lss Well-Known Member

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    Could be your LSN is too lean or rich and your fighting with that. If your LSN is too rich, a lean HSN compensates for it. A lean LSN is also compensated for a bit by a rich HSN. Usually, changing one much requires adjusting the other.
     
  3. Tommi_82

    Tommi_82 Member

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    Visited in garage today and checked my LSN, looks like its in stock setting (hadnt have no need to tune that) is it still possible that screw is too rich or too lean?

    Also noticed that i don't have to screw HSP so much than last summer, in last summer optimum spot was somewhere in 1-1,5 turns, now even 0,5 turns is too much.
     
  4. olds97_lss

    olds97_lss Well-Known Member

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    Could just be gunked up on you from sitting. Might want to take the carb off, take out the needles and the LSN/HSN assemblies, clean them and check the o-rings. Orings in carbs don't last forever. They tend to dry up when sitting and then they leak badly causing bad tune or your tune to adjust on you as the engine runs because they don't keep the needles in place. It's best to put some associated green slime on them to help keep them conditioned and for sealing.
     
  5. Tommi_82

    Tommi_82 Member

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    Sounds logical...
    In weekend i have planty of time to check the carburetor. Also ordered green slime today, i believe i got it before weekend.

    Is there anything to know when dismantle carb?
    Just take off carburetor and then unscrew needles and they come out that way?
    Is there anything that i can broke with unknowing?

    What size are o-rings? I think its better to get new ones allready before to do anything...
     
  6. X

    X Conspiracy of One
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  7. olds97_lss

    olds97_lss Well-Known Member

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    Nothing real special to know. Just don't overdo it when putting the needles back in so you don't damage the needle or seat. If your replacing o-rings, make sure to get the green slime to lube them before putting them on the needle to help avoid tearing them. Take the carb completely apart as in, remove needles, idle screw, the main slide part, the HSN assembly as well as the needles out of the HSN/LSN parts.

    Then when putting it back together, use RTV to seal both sides of the main fuel inlet, carb neck and carb cinch bolt. It can be a bit of a mess, but put it all together, then wipe off the excess RTV before it cures. Make sure to use "sensor safe" rtv. The permatex ultra copper is what most people use. I usually use a q-tip with the end cut off to apply the stuff.

    The last rtv I bought was Permatex Ultra Grey RTV Silicone Gasket Maker. Not sure what's different about it, but it's advertised for use with high vibration applications. I got it because it was grey and doesn't stand out like a sore thumb as I was getting it to seal a sensor plug on my castle brushless motor. Once cured, seems pretty much the same as the ultra copper as far as pliability.

    Here's a thread about sealing an engine if you want to brush up on it:
    https://www.hpisavageforum.com/threads/nitro-engine-sealing.15150/

    Considering the time it takes to do the carb, might be best to do the backplate as well. Will give you a chance to inspect your clutch bearings and shoes too since you will have the engine out.
     
  8. Tommi_82

    Tommi_82 Member

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    Doesnt hear very difficult, so i think that i try seal whole engine in weekend.
    Lets hope that helps with original problem.
     
  9. olds97_lss

    olds97_lss Well-Known Member

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    At the very least, it rules out air leak as an issue. Check your exhaust gasket as well. They can get pretty chewed up on a savage.
     
  10. Tommi_82

    Tommi_82 Member

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    Nothing new under the sun...
    I check the carburetor and sealed engine yesterday, today was test drive day.
    Engine still heats up just before when fun starts...
    I believe theres something wrong in my HSN, it feels kind of loose, no any resistance when try to tune it. O-ring was in good shape, but it ”profile” was like square, not round like all others, also in pictures of carb o-ring set all of rings are round, not square
    I tried to replace it with same size of standard o-ring with round profile but it was impossible to put needle back on its place so i don't know was original o-ring ok or not?

    Anyhow, local dealer has great discount of f4.6 carburetor(only 20€) so i think i order brand new carburetor and try with that.
    If aint work with that i dump whole thing in carages cabin and try to find new hobby...
     
  11. olds97_lss

    olds97_lss Well-Known Member

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    You can try soaking the o-ring in fuel to make it swell back up a bit.
     
  12. ELWOOD

    ELWOOD Well-Known Member

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    Olds , do you know where to find associated green slime ? Its on back order everywhere.
     
  13. ELWOOD

    ELWOOD Well-Known Member

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    Thanks for the info Olds
     
  14. Tommi_82

    Tommi_82 Member

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    Back in business after two weeks.
    Now i got brand new carburetor (i greased o rings with green slime and installed carburetor with RTV)
    I just came back for test drive, i think its propably works little better now, but still its heats way too high. (Temperature meter says 165-170c and feels that it still not gave out highest power) tried tune heats back to around 120c but car was slow as hell and engine sounded like it runs way too rich.
    So now in thinking, last summer i drived with stock spur gear and clutch bell, now i got Robinson Racing 48/16 combo, could that effect so much in top speed? Car doesnt even change second gear, i had tried to loose gear tune screw about half turn but still no second gear...
     
  15. olds97_lss

    olds97_lss Well-Known Member

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    170C = 338F... yeah, that's a tad over "way too high". I try to stay between 240-260F, 275F+ (135C) is too much for me.

    If it's not shifting, then your probably running way too high of RPM's. What gearing did you have before? "Stock" varies a bit. Could also be your slipper is slipping not allowing it to transfer the power to get it up to speed to shift. If it's slipped, then it's more than likely glazed the slipper pad and your going to have to take the spur off, rough up the pad with sandpaper (very light pressure) and put the spur back on. Tighten the nut until the spring is compressed, then back off 1/4 turn. Also use locktite on the nut.
     
  16. Tommi_82

    Tommi_82 Member

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    And second test drive today, checked slipper clutch (no signs of slipping) and also looked inside of transmission, nothing unusual there.
    I think i got it working little bit better again, just need to tune HSP very carefully.
    What is best (right) way to measure temperature? Immediately after full speed run or how?
    Now i got temperatures about 120-135C but still no second gear.
    And well, my throttle servo dies after half tank so need to try to find out new one
     
    #17 Tommi_82, Jul 1, 2018
    Last edited: Jul 1, 2018
  17. olds97_lss

    olds97_lss Well-Known Member

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    Are you sure your throttle is setup so it's opening the carb up all the way? If you take the air filter off, with the truck not running, apply full throttle with the remote. The side in the carb should open all the way.
     
  18. Tommi_82

    Tommi_82 Member

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    Okey, finally got new exhaust gasket and changed it (there were no signs of damage on original one, but just for sure) also double checked that carburetor is opening proberly, everything was ok.
    I think its working much better now ( at least i got temperatures back around 120c) and its much easier to tune now.

    But still wondering couple of things:

    -HSN is now tightened about 1/4-1/2 turn from it stock position, its maybe ok then? (Remember that in last summer right HSN spot was somehere 1 1/2 turns)

    -still no second gear at all, what can do that?

    -still got feeling that aint give out max power and eat to much nitro, but maybe its just between my ears and cause for that second gear problem? Or is it anyway possible that so new engine is finished? Had driven about 6 litres of 25% nitro...
     
    #19 Tommi_82, Jul 10, 2018
    Last edited: Jul 10, 2018
  19. olds97_lss

    olds97_lss Well-Known Member

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    6l is about 1.5 gallons, right? Guessing you should just be well broken in by now.

    Your slipper or clutch could be slipping so when it does engage into 2nd gear, the shift is so soft your not hearing it, then it's just slipping as it tries picking up speed. Or, your two speed needs adjusted.

    If you left the truck off the ground and slowly accelerate, do you hear it shift then?
     
  20. Tommi_82

    Tommi_82 Member

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    Yeah, something like that, one gallon is 3,78 litres.

    Anyway, today i drived several off ground test drives in my garages table, and after little tune in transmission i finally got it shift to second gear, but as you guess, shift was very soft and it was really hard to hear that.
    So next, i had been checked my slipper clutch earlier and it was ok, so i take engine off and remove clutch bell and my clutch look like this:
    https://www.dropbox.com/s/uk8kwdivuznk3tb/Photo 12.7.2018 14.17.19.jpg?dl=0

    https://www.dropbox.com/s/6w8uzym4c9so9zi/Photo 12.7.2018 14.18.15.jpg?dl=0
    That clutch has drived about 1/4 gallons do you think its slipping too much?

    As you can see, i use robinson racing clutch bell and hpi’s aluminum clutch shoes (part number 87196) i mounted it with thicker, golden springs as their manual told to do, is it maybe better use thinner springs?

    Last summer i drived with standard clutch and standard clutch bell, but clutch springs was broken and it was hard to find standard clutch so i replaced it with aluminum one. Anyhow, with that combination there were no problems.
     
  21. olds97_lss

    olds97_lss Well-Known Member

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    I'm guessing with an alloy clutch, worn or not, it's not slipping there. Might want to check your slipper. Take the spur off and see if the pad is shiny. If it is, lightly sand it to remove the shiny, wipe the slipper pad and plate off with some denatured alcohol and put it back together. Fully compress the slipper spring then back off 1/4 turn.
     
  22. Tommi_82

    Tommi_82 Member

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    I reassemble the clutch with old, golden springs and removed spur gear, my slipper clutch look like this:
    https://www.dropbox.com/s/m3j95woy2el8syd/Photo 13.7.2018 19.14.02.jpg?dl=0
    Maybe slided a little bit, put theres still lightly visible sanding marks from last time i removed spur gear.
    Do you think its had been slipped too much..?

    Anyhow i sand it and cleaned it and put back together.

    When reassemling engines clutch, i noticed that clutch bell has been change its colour, just like it been heat very hot:
    https://www.dropbox.com/s/zcx8zwsburpzw01/Photo 13.7.2018 19.34.20.jpg?dl=0

    Is that normal, or is it maybe possible that mine clutch is slipping and heating clutch bell? Is there any method to sort out if clutch is slipping?
     
  23. olds97_lss

    olds97_lss Well-Known Member

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    It will slip some, but shouldn't slip too bad in general if your geared right. It's hard to say how to tell if it's slipping. It's one thing to tell on a truck you know everything else is good, but when your trying to diagnose one thing over another, it's hard to say.

    If you took your slipper apart, cleaned it, roughed it up with sandpaper as well, then I guess all you can do is try and see what it does now after doing the same to the CB.
     
  24. ELWOOD

    ELWOOD Well-Known Member

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    Tommi_82- That discoloration on clutch bell looks like its been overheated right where the shoes run .

    Between the hot clutch and slipper problem and low power and lack of shifting have you put truck on level ground with engine off and radio on and pushed it forward a couple times to see if brakes or something else is dragging and putting load on Truck??
    [​IMG]
     
  25. Tommi_82

    Tommi_82 Member

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    Okei, i cleaned up well and put it back in one piece, i guess that tomorrow morning starts with few test runs...

    ELWOOD: yes, i try to check it everytime when i start to drive that truck is moving freely, theres absolutely no load on truck.
    I think i try to measure clutch temperatures tomorrow...

    Edit, now remember one thing, first run on this spring trucks brake disk drops off (i was using stainless steel disks, now changed back to glassfiber brakes) and jammed brakes when i was driving, but i stopped driving soon as i noticed that so that aint loaded truck at least few seconds.
     
    #26 Tommi_82, Jul 13, 2018
    Last edited: Jul 13, 2018
  26. Jam Racing 1

    Jam Racing 1 NPTB Monitor, Master of the known universe....
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    By the look of your clutch shoes you should take a dremel and deburr the edges of them so you don't get a hangup on the shoes.....
    Also I see rust on the shaft and possibly the bearings so a good cleaning will help alot....
     
    • Agree Agree x 1
  27. ELWOOD

    ELWOOD Well-Known Member

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    Yes to deburring shoes and also the dirt and grime on nose of engine and the look of inside of clutch bell appear to be some type of OIL ,possibly spilled fuel or exhaust leakage both can oil up the shoes and cause slipping.
     
  28. Tommi_82

    Tommi_82 Member

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    Todays test run was huge success!

    In morning i deburr my clutch shoes with file and also cleaned shoes and clutch bell carefully (also cleaned whole engine from above) after that i put whole thing back in one piece.

    I think that now my Savage is working almost as it should be.
    Few things from today:

    -finally find second gear on the run, after all, i had to loose over 1turn second gears tuning screw.
    Did that sound normal? Only change is when i changed original 47/17 transmission to 48/16

    -engine temperature is now stable 120-130C, its not vary so much in large scale, so i suppose there was air leak somewhere in carburetor and/or in exhaust gasket.

    -Also measured clutch bells temperature, it was around 120-130C, does it sounds normal..?

    -still cant do wheelies when start to accelerate on stand, even on tarmac, maybe fine adjustment to LSN helps with that?

    And last of all, need somekind of master tip how to keep brakes in one piece? I had have always problem that screws of brakepads starts to loose of their own. Same thing happens today and finally i have no brakes at all so needed to stop test run.
     
    #29 Tommi_82, Jul 14, 2018
    Last edited: Jul 14, 2018
  29. ELWOOD

    ELWOOD Well-Known Member

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    First on any screw wether its going into metal or plastic always turn screw left until you feel / hear it drop into established threads then screw in , this will keep from cutting "NEW" threads and eventually stripping it out. As far as the brake screws I use the GREEN loctite when putting screws into plastic. Always give the Loctite time to dry. Hope this helps.

    ELWOOD
     
    #30 ELWOOD, Jul 14, 2018
    Last edited: Jul 15, 2018

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