Setting Idle on HPI K4.6

[ShiftPoint]

Hi,

I am not exactly sure if this should go in this thread or the clutch thread it has to do with both. I figure it is really about the engine idle.

I am breaking in a HPI K4.6 engine, in the book it says first tank to leave the TX and RX off, move the throttle servo till the gap in the carb is ¼ of the way open and start, then move the servo till the wheels stop spinning and the clutch disengages. Problem is even with the servo all the way to idle it still engages the clutch, and quite a bit at that. So I figured I will move the idle screw counterclockwise and move the gap tighter to slow it down. I can slow it down enough to, “almost†stop engaging the clutch but never where the clutch isn’t spinning at all.

I stopped the engine because I wanted to ask you guys about a couple things. First is it ok to mess with the idle screw during break in?

Also I noticed tat when it is idling close to correctly air bubbles start to form in the fuel line, I guess there isn’t enough pressure in the tank to push the fule correctly.

One last thing, I am worried about not getting enough fuel in there for breakin, it douse spatter oil still but not like at a faster idle.

It is confusing, they say stop the clutch from spinning but then they say the idle screw is only to be moved after the HSN is set and the engine is running for normal operation.

Any advice would be greatly appreciated, I don’t know why I never got one of these machines a long time ago, it is making me crazy, spending money I don’t have, and just obsessed. I am hooked.


Thanks,

John

 

[samisavage]

I would just leave it, hang the truck from something with a bungee from the rollbar and let it go. That may not be the proper way but is what I would do. That way you are not messing with the factory setting for breakin and it won't hurt anything to let the wheels turn. That is just my opinion.

 

[ShiftPoint]

Hi,

Thanks, I just tried that, I don't hang it I made a stand out of some heavy duty boxe's so it is up at waist level. I did try going back to factory for the reasons you mentioned. I also adjusted the throttle linkage out 1 turn to make sure it is all the way against the needle but when I try to run it like that it is out of hand, I mean it is screaming. This is so much different than my last break in it is crazy. The K4.6 has to be a lot leaner at factory settings than the F4.6 is, one thing it is taknig forever to go through a tank of fuel, the F4.6 drank that fuel like I couldn't believe (still does) this one just well I ve been out there on and off for the last 3 hours and I am still at half a tank. Oh also at fatory the temp got up to 274 degrees in no time, actually my first reading I did. yesterday I even made it more rich and it didn't make much difference.

Boy, just when I think I am learning a little about these machines, bam knocked back down to first day newbie 🙂 I wouldn't think these 2 engines would be that different. the other oe was a pain in the neck to keep running but I felt a lot safer breaking it in.


Thanks,

John

John

 

[samisavage]

Wow maybe try to richen both low and high needles some and turn the Idle down i guess. Thats strange as for being back to newbie I feel ya I get so frustrated with mine sometimes I just put em away. I guess wait and see what other ideas come up. When I broke my last motor in I just hung it and leter run a couple tanks but it wasn't screaming just a little over high idle hang tough I'm sure we got ya covered might just take a few for the response that gets it. good luck.

 

[ShiftPoint]

Sami,

Thanks, What I did when I brought it in I took the filter off and rest the gap so it is at about 1mm, I think maybe I had it open too much, it was getting dark when I last tried the factory setting and that idle screw is kind of hard to see anyway, I probably had it open too much when it was screaming. We will see tomarrow.

If that don't work I may just do like you said and richen them or maybe call HPI and see what they say. I just want to make sure it is normal, it's just so much richer than the lastr motor and the temp is so much hotter i wonder if maybe one of the needles is not right or something. The other engin, I don't remember exactly hot hot it got but I know it took a long time to get to 210 degrees and I don't think it got much hotter than that ever during break in.

I will let you know what happens,

Thanks,

John

 

[ShiftPoint]

Hi,

Did I mention YOU GUYS ARE GOOD!! Sami, you nailed that one right on the head, the LSN is what did it, I richened it up it took care of every one o my concerns! The temp stayed about 200 degrees (once it got warmed up) it slowed the idle down a lot, and started using more fuel and more oil was flowen. I set it to BDC and am letting it cool, I red in one of those advanced breakin writeups' to let it do that at about 200 (if I am remembering right).

Now that I already did it, I remembered reading on some website once that a guy said he had the same problem, he said it was because of his latitude or humidity, something location related and he was in SC, or NC, I am in south FL and only a few feet above sea level, location has to have something to do with it, but then look at how my last engine was exactly opposite???

I figure on these HPI mill's I will pretty much follow their instruction's with your guys tips. Then when I am ready for a STS or something like that Ill do the more advanced breakin's. You guys have so much cool stuff on this forum I hate lookin, just makes me "want want want" and I know I am not even close to ready for it.

Thanks for the help sami!

John

 

[samisavage]

Glad you got it Wister! these lil mills are very tempermental I can have mine tuned sweet and take it up to the mountains and have to retune it. They are very sensitive to elevation, tempuratue, humidity ect.. I've had mine out bashing with SJ running great then a couple hours later had to retune due to temp humidity changes. It's all part of the game they will change tune day to day or even hourly sometimes.