Engine Help?

[ulua]

Hi All,

Sorry if this has been posted already, I'm a noob to this forum and to R/C. I know nothing about it.

I have a Savage 21 with a brand new HPI 25 engine on it. I wish I found this forum before I tried to break in my engine. Initially my engine would not start
so I started messing with the High, Low screw and the Idle till I got it started. Now it's out of factory setting. I broken it in per the engine manual. Noticed that my truck had no top speed and only decent low end. So I read the manual and put my engine back to factory setting. High and Low from fully closed opened them 3.5 turns. Now my Savage seems to be performing a lot better. better low end and good top speed. Here is my issue and don't know what to adjust. My engine temp is around 180 to 200 F. I noticed that when I full throttle the engine and release the throttle the engine keeps winding and the truck moves as if I am still pressing of the throttle, it does not go into idle mode and costing immediately as it should. After a few seconds it revs down to idle and truck coast like normal.


Thanks,
ulua

 

[Slimshamis]

Lsn

LSN is to lean "low speed needle setting" back it out "counter clockwise" 1/8 th turn run it see if it improves make a few passes if its still doin it back out another 1/8th turn you should always see a steady stream of smoke at full throttle if you don't then you high speed needle setting is too lean

 

[Tominator06]

Hey there ulua. Take a look at your idle gap. it should be at around 1mm when the throttle is closed. take off the air filter and look down the throat of thr carb. When the throttle is closed you will still see a slight opening. This is the idle gap. It is adjusted on the side with the idle screw. When it calms down does it have a nice low idle or does it see to want to creep at idle? Seems odd to be hanging up at factory settings like that. You mentioned setting everything back to factory and I just wanted to make sure you checked the idle gap as well. Keep us informed.

 

[modified]

Welcome to the hpisfflash ulua.

 

[ulua]

Hey there ulua. Take a look at your idle gap. it should be at around 1mm when the throttle is closed. take off the air filter and look down the throat of thr carb. When the throttle is closed you will still see a slight opening. This is the idle gap. It is adjusted on the side with the idle screw. When it calms down does it have a nice low idle or does it see to want to creep at idle? Seems odd to be hanging up at factory settings like that. You mentioned setting everything back to factory and I just wanted to make sure you checked the idle gap as well. Keep us informed.

Tominator06,

Thanks I will check the idle gap, also how does the linkage rod affect the R/C if it was adjusted. My brother was playing with it when we were first trying to start the truck, The inner rod is kow flush with the adjustment Knob, he said that, that is were it originally was.

Also I noticed that when I pick up the truck with it running on Idle the tires spin. it's not a real slow spin but it's not a real fast spin either. Is this normal?
if not, is it the idle screw on the motor that needs adjustment or the TH Trim
on the controller. What about the linkage rod does that need adjustment too.
like I said my brother was playing with that also. now the inner rod is flush with the adjustment knob.

Thanks,
ulua

 

[Tominator06]

The tires spinning could be linkage and or a clutch problem. You want the throttle fully closed and still have some play in the brakes. I am not very familiar with the savage 21 or 25 but I am sure someone will jump in who has a better idea. Lets start with the idle gap since that's one thing we can check off the list. Then check the linkage. If the linkage got messed with it could very well be the culprit.

 

[Tominator06]

when changing the idle gap you adjust the idle screw on the carb body. the radio trim should be setup once with the linkage and pretty much left alone.

 

[ulua]

Thanks, I will keep you updated when I get a chance to run my truck again.

 

[ulua]

hello,

I didn't get a lot of chance to play with my truck today, but I did adjust the Idle position, now the idle sounds lower(slower) but now the truck keeps dieing on me. Do I need to keep adjusting the idle or do I now have to go back and adjust my High/Low valves?

Thanks,
ulua

 

[Tominator06]

Now you may have to lean the low speed needle just a tad to keep it running. Does it still try and spin the wheels when you pick it up?

 

[ulua]

Aloha All,

Well yesterday took my truck to the park to tune it and run it, and it was a no go. Here is what Happened

First my carb gap was set around 1mm, now with it as 1mm I had a hard time getting it to start or stay started. after adjusting the HSN and LSN to keep it running, at full throttle my truck is acting strange. It would go then slow down go then slow down as it i'm playing with my throttle but i'm not I have it at full throttle.
No matter what I adjusted it still did it. Other thing is my truck also will keep conking out. at neutral, break or at full throttle. at this point I don't know what to do. So I took it to one of our RC stores but they were already closing so the guy did not start it, but he looked at my settings and said that my carb gap was good 1mm. he then adjusted my HSN and LSN to what he thought shoud get my truck running. He said to try that and try to tune it and if still not working bring it back on Monday.
So I went home and tried to run it and same thing car would die at neutral, or when break is pressed or when gunning it. and it would still do that speed up, slow down thing. I finally gave up

I even tried adjusting my idle gap but no help. What my brother found was the card needle would not stay in the same position all the time. ie: at neutral and break seemed ok, but when he pressed the throttle fully open the released it back to neutral the pin would close leaving to gap. So I think this is causing the truck to die.

any suggestions?

Thanks,
ulua

 

[ulua]

sorry don't know how to edit my post. wanted to add that when my brother was adjusting the LSN It to seemed to open and the gap in one direction and close the gap in another direction. it this normal?

Thanks,
ulua

 

[ulua]

sorry don't know how to edit my post. wanted to add that when my brother was adjusting the LSN It to seemed to open the idle gap in one direction and close the gap in another direction. it this normal?

Thanks,
ulua

used the quote to edit my post

 

[Tominator06]

When adjusting the idle gap did you use the idle screw in the side of the carb or move the linkage? Do you have a throttle return spring? The linkage sounds like its not setup correctly. May be sticking somewhere. Tough to tell when I cant see and hear it run. Hopefully we can get it figured out. First should make sure everything mechanical is setup correctly if it has inconsistent throttle input results.

 

[ulua]

Hey Tominator06,

thanks for the reply. I did use the idle screw to adjust the gap, but a few days ago I did play with my linkage, I was looking on youtube on how to adjust the linkage. and I don't remember which one it was but the author said that when truck is off, it you push you truck it should be free wheeling with no resistance, if there is some resistance then the linkage is too tight causing the break to be rubbing and would cause break wear down and to fix this he said to loosen the linkage. so I did. is this correct or did I pick the wrong video to watch LOL.

Thanks,
ulua

 

[Tominator06]

Thats for brake setup but you also need to be sure the throttle is all the way closed when the radio is on and no throttle input. if it is inconsisantly returning to neutral you will never get a tune on it. I recommend some sort of throttle return spring or rubber band not only for safety but to insure the throttle closes everytime. Sometimes the carb barrels can stick from improper setup and may need the help getting back closed all the way without making the servo keep pressure on it to do so.