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HELP with tunning. PLEASE

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N

nicguz

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  1. Bashing
Ok, so I got a savage xl a while back and I guess I had a bad motor because the piston broke. Lucky right? So, I finally got a new motor and am trying to do the break in and I'm getting a lil frustrated. And I was just looking for help please. I'm at the point where I'm trying to tune it but, if I make it rich it wont start so I turn it back and I adjust the idle and it wants to go then I turn it down and I gotta trim it more to stay running. Then it runs for a while and I try to make an adjustment and it dies and then I try and to get it to shift thru the gears and it dies or I put the break on and it dies. I would just love some help. Thank you all.
 
Don't worry about trying to get it to shift just yet. Mine didn't shift until the fourth tank or so and didn't pull wheelies until a good 8-10 tanks throught it...

How many tanks do you have in it now? You'll want it to run fat (rich) during break in and it does get a little frustrating. As it loads up with fuel just blip the throttle to clear it out, but don't try to grab full throttle just yet or try to pull the trigger too fast, or it will cut out.

HTH...
Mark
 
I've got 4 tanks thru it now. I just started driving it around nice and slow at about 1/4 throttle last tank and now half throttle. Maybe I'll just run a couple more tanks thru it and start leaning it out. I know it just takes time. Thanks for your input. Trying not to get frustrated. Ha. I'm just new to this and trying to learn but, I know what these trucks are capable of. HUGE things. I'm happy I found this place. I can see this place is gonna be very helpful. Thank you.
 
Yes, patience grasshopper! I have a brand new HPI F4.6 engine for mine but dreading the break in so I'm sticking with my original S-25 until the pinch is gone...

Give it a few more tanks and see how it goes...

Mark
 
Omce you've broken the new engine in properly it'll b easier to tune. Go through the tanks, brake the engine in properly then fine tune it.

I've been trying to fine tune my XTM for the past 2 days and that things been broken in and raced numerous times hehe. Still no luck. I've learned since trying to fine tune that the min you get frustrated walk away! If you try to tinker on a RC or especially fine tune a Nitro engine while frustrated you'll make it only worse hehe.

Time and patience man. Don't try to rush anything.

"Hybrid Sucks"
 
Thank you both for all you support. I'll get some more fuel thru it and let you know how it goes. I'm sure I'll be asking plenty more questions. HA HA.
 
Just make sure the temps aren't spiking. 200-230 is optimal. Make sure to put the piston at bottom dead center immediately after you shut the engine off.
 
Ok. My temps are good so far. I can't find anything in the manual for putting it at bottom dead center. Do you do that by just turning the clutch?? And my truck is at work right now so I'll be able to do all this stuff tomorrow. I think I'm gonna make sure all the needles are flush and check my 1mm gap. But, what screw do I adjust to get that 1mm gap? Is it the idle screw? And do I make sure the throttle trim on the remote is all the way to the left before I start that or just put it in the middle? Is that why it dies when I put on full brakes because the gap is open to much or closed off all the way? Thank you all.
 
To find bottom dead center, take the glow plug out, move your flywheel until the piston is as low as it goes,(this is bdc) and put a reference mark on the flywheel. Turning needles blindly is asking for trouble. If it starts and runs, leave them alone unless it's getting hot or is too rich to run. Needles are to be adjusted only when the engine is running and up to temp. The idle screw is what stops the carb from closing completely. 0 out your trim, apply the brakes, and then adjust your idle. Applying the brakes while adjusting the idle ensures that the carb won't close all of the way, ah, when you apply the brakes.:) Then make sure the carb linkage is working right otherwise. Make sure the carb opens all the way when the trigger is pulled(without over-extending the linkage), that the carb closes against the idle screw when your finger is off of the trigger, and that the brakes work.
 
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Ok. Thank you so much. So all the idle stuff, brake and bottom dead center can be checked before I start it up right? I'll try all that tomorrow when I get to work. I'll post how it went. It's been running ok for the last couple tanks. It just dies sometimes and the temps are low. Like around 200-220. And it kinda sounds like it's not running real smooth that's why I thought I would adjust the high end to lean it out. (1/4 turn) But I did that and I had to trim the throttle up to get it to run then I put on the brakes and that's when it would die. So I had to take a break and walk away. LOL. But, I'll check the carb and brake tomorrow and see if that's it. THANKS again. This place is awesome.
 
Yup, check all that before the first start. You'll get it. I bet it just needs another couple of tanks before you can start tuning it more...

Mark
 
Are you sure your not mistaking the idle screw for the hsn? If you turned the idle screw counter clockwise a 1/4 turn, this would drop your idle. Making you have to compensate with the trim. Then when you brake, and the servo moves the other direction, it closes the carb against the idle screw, which(maybe) you now have adjusted too low. The hsn is the big brass screw, right where the fuel line hooks up to the carb.
 
Yeah, I got the right screws. I think I just may need to run some more fuel through it before I start trying to lean it out.
 
200-220 is a good threshold for break-in. Your best bet is to do what your already thinking. Get some more fuel through it, stopping every 3-4 minutes(after the engine is up to temp) to let the engine cool down. Just don't forget to set the piston at bdc, This is very important. It'll loosen up for ya.
 
Ok. Got some more fuel through it this weekend. Eveything was going good until the end. It started to make a woble sound like it wanted to rev up and die and rev up and die again. I check the temps all the time. They are usually around 220 which is good but when it started doing that I checked it and it was above 300. I was so scared. I cut it off let it cool and put in some after run oil and started it up the next day. It's fine bit, what could cause that cuz I'm always checking the temps and tge HSN is at tge groove. I'm not sure what happened. And I'm also having trouble priming it for the first run of tge day. I put my finger on the exhaust port and use the roto start and I dint see any fuel going through the tube. So I actually blow in the other one till it gets to the carb. I was wondering if this is what caused the temp spike and if anybody knows why it's not working right. Thank you.
 
Make sure you don't have any air leaks in the fuel system. Check all of your fuel line for cuts or abrasions. Also ensure the fuel tank cap is seated. My O-ring has started to go bad and sometimes I get an air leak at the tank. I have to push the cap down to force it to seal and then the fuel system will prime.

Also on first cold start of the day it wants to stall, so I leave the ignitor on for another 30 seconds or so after it lights off and I also pick it up and rev it a little (not full throttle) and then it stays running fine.

HTH...
Mark
 
I've had the same problem by not being able to prime the carb by plugging the exhaust. Come to find out, low compression. Check the compression on your engine.

My .25 xtm was holding the tune worse and worse after each tank and it was getting harder and harder to prime it by plugging the exhaust. At first it would take me 3 pulls to get a nice prime in the carb then 6 then nothing at all.

Compression...

"It's Only Money, Right?!
 
I know its a new engine and you are barely braking it in but it could be a manufacturer error. Happened to my friend twice. 2 Losi engines, out of the box with low compression.

"It's Only Money, Right?!
 
Ok. I'll check those. Thank you guys. I'm still new to this stuff so how do I check the compression? I hope it's ok cuz this is my second motor. The first one I had the piston broke. I hope it's just a fuel line. Could that be why it got so hot last time. It wasn't getting proper fuel maybe.
 

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