Starting and Tuning Help

[pnstalum]

New to the forum and hobby, decided to pick up a Savage 25 from a friend for me and my son to work on and run. Have run it several times, seemed like it wasn't tuned well... I'm guessing running a little rich based upon the fact the glow plug was wet and not turning gray at all.

Stripped the clutch bell the other day and replaced it. Also put a different exhaust on (not sure what it is... just came with the truck) and tried to run it yesterday. It started up and ran, but not very well - seemed to "hesitate" a bit as it was accelerating. Decided it was time to try my hand at tuning and reset the needles back to factory (btw, the motor is a Dynamite Mach .26). At that point the pull start was harder to pull and when it did fire up it would only run for a few seconds. I assumed it was the low speed needle being way to rich at factory settings and started to lean it out. It seemed to get better and start running longer, but is seems a lot of fuel is coming out the exhaust pipe now and when idling the wheels are spinning.

It was getting late so I stopped (didn't want to upset the neighbors ) and wanted to check in here to get some advice. I'm thinking I just need to continue to lean out the low speed needle so it idles for at least 1 minute, the start running it to adjust the high speed. Does this sound about right or do you think there may be something elso going on or something else I should be doing. Thanks!

 

[Flipmode]

Get a temp gun first, then tune it.

You need to be around 250°

 

[pnstalum]

Was planning on doing that this weekend... any recommendations on type of temp gun, or are they all pretty much the same? Where is the best place to take the measurement, cooling head, block? Am planning using the tuning flowchart as well this weekend. Any advice is appreciated.

Thanks!

 

[ChiefGeek]

I bought a cheap $25 one from the LHS. Buddy has a cool one that has a loop wire on it that you mount in the car and it monitors while you run and you can review the max temps and average temps. Keep in mind that the best place (imo) to test for heat is the area around the glow plug, so this monitoring method of the traxxass would potentially not be the most accurate depending on where you run the wire.

 

[cwal1774]

I always check the temp at the glow plug. I think 250 is a little on the chilly side (imo) i try to keep mine around 280.

 

[pnstalum]

Thanks for the advice on temperatures. I was planning on doing some tuning this past weekend, but this thing is just not running well. Very hard to get started and keep running right now. Based upon the tuning flow chart, I believe the low speed needle is still too rich as it bogs when accelerating and I have to feather the throttle when cold. If I apply the brakes hard, it stalls but I have at least 1mm or 1.5mm open when the carb is closed so not sure why it is stalling. Also, what is the best way to test compression... I have heard just turn the flywheel and there should be resistance.

Not sure if the engine has been sealed... but maybe that is my next step.

Thanks!

 

[bgbdwlf2500]

Thanks for the advice on temperatures. I was planning on doing some tuning this past weekend, but this thing is just not running well. Very hard to get started and keep running right now. Based upon the tuning flow chart, I believe the low speed needle is still too rich as it bogs when accelerating and I have to feather the throttle when cold. If I apply the brakes hard, it stalls but I have at least 1mm or 1.5mm open when the carb is closed so not sure why it is stalling. Also, what is the best way to test compression... I have heard just turn the flywheel and there should be resistance.

Not sure if the engine has been sealed... but maybe that is my next step.
Thanks!

Never a bad idea, i definately would start there.

 

[cwal1774]

Also check your throttle linkage it maybe that the gap is closing when you hit the brakes causing it to die.

 

[pnstalum]

Quick update. Spent some time tuning and adjusting last night... turns out it was the throttle linkage / adjustment that was causing most of the issues along with an overly rich setting on the LSN. It appears when I reset the mesh on the spur / bell, that slight movement of the motor caused the throttle gap to close with the existing servo adjustment. I adjusted the idle screw, LSN, servo setting and bam... started running great (at least for now ) I will still seal the engine at some point and we'll see how it goes next time I take it out. It is both frustrating and rewarding at time problem solving and working on these things. I think I would get bored with electric as I enjoy the tinkering as much as driving.

 

[cwal1774]

I always disconnect the throttle linkage when i set the gear mesh then adjust the linkage accordingly.

 

[farm boy 530]

I know this is and older thread, but any advice on adjusting your throttle linkage? I'm having a bit of trouble....

 

[RayRay]

Farm boy 530
I am new to the forum so be patient. I have a savage xl and went through a 10 tank break in period. After the initial tuning I noticed some issues with the throttle linkage as well, especially since the brake and gas share a common servo. This also caused frustration with the proper breaking as well. i have spent at least 25 hours trying different combos settings and after much research have found this to work great. Turn on the radio and truck and set your throttle trim to zero, then remove the servo screw and linkage connecting to the carb. using the servo arm as a clock face, set the narrow portion of the arm slightly behind the 6 o'clock area and the opposite end where the carb. linkage connects, so that the top is just behind the 12 o'clock range. This will give you about 12 threads showing on the carb. linkage. Then when I start my truck, I adjust the throttle trim to one above zero. Also, I replaced the brake linkage spring with a section of fuel tubing. I run around 170f at idle and 230 to 240 at full throttle. The breaking is good, but can be greatly improved perhaps with a better servo or maybe stainless breaks. I hope this helps.

Ray

 

[farm boy 530]

I did get my throttle linkage and idle adjust screw balanced for a perfect idle. took 45min to an hour to get just right, but when I start my car next I'm sure it will need little adjustment! I read a few times but couldn't follow just what you were saying. By throttle arm did you mean servo horn? and I'm not sure what you mean "Threads on the carb." I know I am running ok for now, I do need some screws for my pull start though....

 

[RayRay]

Sorry, my terms are a little off. I was referring to the servo horn and the threads on the carb. arm. I am looking at doing some upgrades to improve my overall performance. One, is I have seen a Spektrum digital 2 0r 3 channel radio that has telemetry, steering wheel tension adjustments, vehicle temp. display and speed all with-in the display screen. I have no idea if this radio can be used. Also, I have read that a new steering servo will improve steering, while the existing steering servo can improve the throttle and brake set-up. Any advice on the matter?

 

[farm boy 530]

No I sure don't as I'm real new to this also! Maybe someone more experienced will chime in! Good luck!

 

[pnstalum]

Well, I'm back. Have not had too much time to tinker and run the truck... football season for my 3rd grade son takes up a lot of time in the fall. Anyway... had the truck running pretty good, biggest issue was it would cut out after running for awhile, which I believe is mainly caused by it running too lean. a couple weeks ago I went to fire it up and the pull start broke. had to fix that three times (used masonary string and it would break on the first or second pull, finally bought string for a pull start) and just tried to fire it up again yesterday... of course now I cannot get it to idle for more than 4-5 seconds and it just dies, even if I try goosing the throttle. The symptom says the LSN is too rich.. but I keep adjusting and no change. Carb is set to 1mm. What is your normal trouble shooting procedure for this starting issue? It is cooler now.. but when I tried yesterday it was in the upper 60's, can the weather affect the tune that much?

 

[farm boy 530]

I would think it could myself but not fully sure. Have you tried advancing your trim a bit until she warms up? If tapping the throttle doesn't work it may not be the issue but worth a quick try! Then you can trim it back as it warms up.