Engine stalling again

[MikeK1981]

OK I had my engine running great for a couple of days but it started doing the same thing I was having trouble with before, engine shutting down when coming down to idle. Could a dirty air filter be the culprit? The only way I got rid of it before was adjusting ALL the needles on the motor until I got it right. To make a long story short I got the MSN out of whack and had a hell of a time getting it running again. It ran good until today. I cleaned the outer element a couple times but when I cleaned it this time the inner one looked a little dirty too so I cleaned them both. I started retuning it earlier so my settings are now different and will have to tweak everything again, but could the filter have been causing this problem because the motor was not breathing well enough? Does this sound familiar to anyone here? Also I don't have any filter oil, can I use after run oil to lube the inner element of the air filter?

 

[maximusraylius]

ouch! that blows ...its just your carb needs readjusted again... its always a good idea once tyou get it adjusted pretty sweet most the time you never really have to adjust the lsn... youll always have to adjust the hsn from day to day from hour to hour depending on temps outside air ect... so start off by setting the lsn back fllush.. then adjust the hsn so it gots power and smoke but itll have a lil sluggish feel to it cause the lsn is still not adjusted... now its time to adjust lsn.. barely turn it to get a crisp throtle response and then your set... but for the most part once lsn is golden... just adjust hsn to tune it from hour to hour day to day what ever,,, just rem good smoke and good speed lots of power your golden. as for the air filter.... any oil is better than none ... but you need to get filter oil for sure...and yes a dirty filter will mess with your tune all day long lol... good luck hope this helps... happy bashn

 

[MikeK1981]

That's what's wierd though the tune still seemed sweet it just could not come to rest at idle without stalling. It could idle as long as I wanted if I let the motor come down slow but if I was on the throttle and then let off suddenly it would die and it does this even when the idle is set too high so I know it's not that. If I have the LSN and MSN flush like they say this problem is worse. The only way I got it to stop is to have the MSN out from flush and the LSN in from flush. Why that worked I don't know! I got the filter cleaned and I'll try over again tomorrow.

 

[maximusraylius]

welll... beings it wants to stall as you come to a stop its a idle thing i think,... you said it does it when the idles set to high as well... uhhh thats not the right way to keep it from stalling lol if the idles to high its grabbing the clutch bell so when you aply breaks it stalls the engine so a lower idle might cure the problem... and it might be just on the radio itself make sure the throtle trim knob didnt get turnd a lil .. might be something that simple.. goood luck..

 

[AllanQ]

put the msn at flush and keep it there. that venturi really does not need to be messed with. Sounds to me you are a little rich on the lsn, so you may have to lean it in small increments. Check the gap on your carb. Typical number everyone says is to have a 1mm gap. the gap setting in the carb is not a hard setting and will change based on your engine, but it gives a good starting point. make sure your throttle trim on your TX is set to neutral when checking the gap and your linkages. Let us know how everything works out for you.

Q

 

[Purenitro]

Check your clutch, it may be hanging up causing these tuning issues. It is very hard to set your idle if your shoes are dragging, could be as simple as a broken spring, worth a look anyways.

 

[MikeK1981]

Thanks for the help. It seems like I haven't had much fun with this thing yet. 1 3/4 gallons through it and it has only ran good AND reliably for about 4 tanks. This stalling issue is the only complaint I have about the truck over all, but it's really taking the fun out of it. It is a blast though when it doesn't stall everytime I let off the throttle LOL.

 

[MikeK1981]

BTW Maximus it's not the brakes because they are not dragging and it is not hitting the brakes that makes it stall it is when I let off to coast. Like I said before, when I close the throttle slowly it won't stall and it will idle all day long and I can hit the brakes with no issues. It stalls when the motor spools up a ways or I give it a lot of throttle and let off too suddenly. It's wierd I can drive the truck around fine at lower speeds but as soon as soon as I try to get on it, it stalls after I let off. I thought it was loading up on fuel but it seems like leaning it out on either needle just makes my temps go way up and does nothing for the stalling. I've tried richer, leaner on both needles and nothing seemed to work until I got the MSN just right and then it worked extremely well for a couple days but now it is off again. When I set the MSN and LSN to flush it does not work well at all for me, I don't know why. Should I just send this thing back to HPI and see what they say? I'm just about at the end of my rope here. I thought I finally had it and then it just starts doing the same thing out of the blue. Should I just take the carb apart and check everything out? I don't want to damage my needles though.

 

[AllanQ]

unless I missed it, what temp are you considering too hot? LSN at flush is typically a break in setting and sometimes needs to be leaned out after the break in. This is also a sensitive needle so do not do any large adjustments on it, 1/12th turn at a time until it is snaps off the line the way you want it too.

BTW what motor are we talking about?

Doesn't hurt to check the air filter and clean as necessary. A dirty, nasty filter will give you problems also.

oh yeah, if you are not already doing it, adjust one needle at a time. making adjustments to both needles at the same time will most likely cause more frustration.

 

[MikeK1981]

It is the 5.9. And I have seen 300 but I don't really like to see 280+. I'm tryin to keep it like 250 or under maybe 260's tops. I had it running 230's really well until I messed with it again LOL. I just took all the needles out and inspected them. The o-rings look ok so I set the MSN at flush, the HSN 1.5 turns clockwise from the line and the LSN just in from flush and I'm going to start over. I notice the MSN has 3 small holes just under where the HSN goes, does one of these holes need to be lined up with where the HSN goes in? If so, this could have been the source of my problem and I'm thinking I got lucky with the setting before and maybe one of those holes got moved a tiny bit causing the problem again?! Anyhow, it is set at flush with one of the holes perfectly lined up with the HSN, I shined a light down the brass stem for the HSN so I could see the hole in the MSN down inside there, and I used some thread lock so it won't turn on me again... IF that's what happened in the first place. We'll see how this works.

 

[MikeK1981]

Also, my linkage was not OPENING the carb all the way (almost though) but it was still staying open around 1mm when fully closed. Would the carb not opening enough affect the fuel intake and cause the motor to load up on fuel for some reason when I gave it a lot of gas and then let off or am I splitting hairs here?

 

[AllanQ]

good luck. 330+ is definatly not a good number, but don't tune the engine to a specific temp range. These motors, once tuned, like to operate at a certain temp. Once you get it tuned in, check the temps to see where it like to run at. then use that temp as a metric to determine on the fly if anything is going wrong. One thing that affects the motor temp also is air flow to the cooling head. If the head is barely poking out of the body, that is not enough circulation to properly cool the motor. If not done, and not saying you haven't done this already, but cutting a hole in the windshield will work wonders for the temp.

 

[AllanQ]

if the carb isn't opening all the way at WOT, all you are really doing is loosing top end performance. You will need to do some linkage adjustments or check the endpoint on your TX(if applicable) to fix, but really isn't the cause of the problem you are having.

 

[MikeK1981]

Yeah that's what I figured and I did the linkage adjustments already. I have cut the windshield out and dremeled the grill to make it a functioning grill on the stock XL body. It came out pretty cool. I know about the airflow thing, I'm going for 230's on the cool end when it's getting good airflow and maybe upwards of 260 when it's not getting enough air. That's what it was running when it was good, I just have to solve this stalling issue. I'm gonna go run it a little now and see if I can't get this thing dialed in once and for all LOL!

 

[MikeK1981]

OK I figured out exactly what my problem was. I guess the LSN was too lean. I re-tuned all the needles and I am getting awesome performance. The only thing is it doesn't have the punch off the line that it could have because there is a point when the LSN brings back my stalling problem when I lean it too much. I can richen the LSN just a tiny bit from that point and the problem is eliminated. Any tips from anybody on where to go from here? I'll most likely just leave it alone cause it's running great and keeping temps in the mid 260's at the highest, but I'm still curious to know what would happen if I changed the pipe or maybe went richer on the LSN and leaner on the HSN? The lag off the line is very small, just a split-second delay went I hammer the throttle and then it hauls the mail but the lag is just enough to prevent any wheelie action. I can live with that if that's what it takes to keep it running reliably but I'm curious to see if anyone here has any more advice on this issue. Is this one of the reasons why people don't care for the k5.9? I had it doing wheelies from a stop but can't seem to keep it that way and get rid of the stalling thing at the same time.

 

[canucksavage]

wheely problems may be solved by tightening, or replacing slipper pad, and also check your clutch shoes for wear.

 

[MikeK1981]

I'm pretty sure it won't wheelie because of the LSN being a little bit rich because when I lean it I can get some good wheelies from a stop but the stalling issue starts to come back again. I was wondering, could this be an air leak issue? I have had this problem from day one so maybe I got it with some sort of air leak.

 

[maximusraylius]

ooofffff so many ppl say they got air leaks when all else fails lol I'm ant sealer never seald a mill.. if you got a leak it would be in the rubber o rings ... but I'm highly doubting it lol... just my 2 cents worth ... but I'm sure if you make a thread on your mill asking if they think its a air leak youll get tons of ppl telling you it is . but imo its not its a tuneing issue lol theres some mills that have such a fine line on tuneing it ...ohhh btw what fuel you useing? some fuels are pitas to tune to.. and wont give you the full power .... higher grade fules are best for power and tune easy to ...i like losi nitrotane a byrons and another that i run now lol.good luck happy bashn..

 

[MikeK1981]

Unfortunately, my LHS is pretty small and all they had was Sidewinder and Top Fuel, so I'm using Sidewinder 20% nitro with 12% oil. If I stepped it up to the 30% what plug should I use with the k5.9?

 

[maximusraylius]

i think your better off with the side winder fuel over the traxxas fuel .. traxxas fuel is way to oily. as for the 30% if you decide on that you need a cold plug ..i don't know exactly witch one to recommend,, but you need a cold plug for that percentage. you could get away with a medium plug or a medium to cold range plug. i use a flat medium plug but thats just cause i run 20% and 30% in my trucks and the medium plug is ok with both. but ide recommend a cold plug for you if you choose the 30% ....hope it helps you out ... happy bashn..

 

[canucksavage]

I'm pretty sure it won't wheelie because of the LSN being a little bit rich because when I lean it I can get some good wheelies from a stop but the stalling issue starts to come back again. I was wondering, could this be an air leak issue? I have had this problem from day one so maybe I got it with some sort of air leak.

i say find your best tune then try these suggestions if you want better wheely action
wheely problems may be solved by tightening, or replacing slipper pad, and also check your clutch shoes for wear.

 

[MikeK1981]

I don't think it's the slipper cause I can tell the motor just isn't snappy from idle. It has a weak throttle response, just for a split-second, then it takes off like a bat outta hell LOL.

 

[maximusraylius]

ok this is where your low speed needle comes into play.... it needs adjusten slightly to get a fast crisp throtle response,,, if its still flush then turn it in 1/16 turns or less at a time to get a crisp throtle and take off... sounds a lil ritch to me .. but if its turned in at all it could be on the lean side as well... the lsn is very sensative one to adjust don't take much to make a huge differeance ... good luck hope this helps ... happy bashn..

 

[MikeK1981]

I'll try leaning the LSN in tiny increments to see if I can push the point between good throttle response and the stalling problem.

 

[MikeK1981]

I was thinking about this... If my idle was set a little bit too high and my LSN too rich, and if I lowered the idle and leaned the LSN some would I need a hotter plug to keep it running? I was thinking that maybe the motor is stalling because there is too much air and not enough fuel when it settles to idle. Would a hotter or colder plug keep it running with less air and less fuel at idle?

 

[maximusraylius]

hmmmm good thinking you got there ... but no it don't work that way as far as the plugs go...different plugs are for differene heat ranges fuel mixters ect... just out of curiousity are you the one running 20% sidewinder fuel? i cant rem who i been helping out with that fuel lol.anyways what fuel and plug combo you running right now?

 

[MikeK1981]

I threw a medium-hot plug in there today with the sidewinder 20% nitro and 12% oil. It seemed to work really well. I had to lean it a bit cause it was running rich and barely getting over 200 but once I got it adjusted it ran good and maintained 230-260 depending on airflow and did not even try to stall. I was having a blast with it and then it seemed like my bottom end was getting sluggish. Then the truck started acting wierd. It would stop even though I was on the gas, and my first thought was that the battery was low and my fail-safe was kicking in. But then it would drive for a second or two and then stop again. It did that for a minute and then the throttle servo quit working all together. I inspected it and everything seemed ok and the servo plug did not come loose as I thought. The servo won't do anything and I plugged the steering servo into both channels and it works fine so it's not my radio or receiver. I took my fail-safe out and that didn't fix it either so i guess my servo is dead! I'll see if HPI will replace it on monday. I have only ran 2 gallons through the truck so hopefully they will. Any suggestions on good replacement servos, I might replace both at the same time with some nice fast/high torque servos with metal gears. I can't remember if the XL has metal gears or not but I'm starting to get fed up with this things constant string of problems so I want to make it more reliable with better gear.

 

[maximusraylius]

good plug on that percentage fuel..as for the servos .. I'm not that great on recomending any lol..I'm stilll working that out on all of mine ... you get what you pay for my next set of servos are going to cost me a small fortune ... around 230.00 bones so just keep that in mind.. the better are a lil more expensive..happy bashn ...

 

[unicorn87]

Interesting same mill,same problem..Did not have a time to mess more with needles..

 

[MikeK1981]

My mill does it when it's hot too though, from what I understood from your other thread you said you can't get your engine to start or warm up. Mine starts and runs great I just can't let off the throttle suddenly.