Losi 454 tuning help

[Mr Clickerson]

I have a brand new 454 in a Savage 25, with an aluminum HPI pipe, and I'm a bit unsure of my settings. I've got the HSN at 4.75 turns out from closed, and I had the LSN out about 2.75 turns from closed, and outed it a bit more, though I'm not sure of the results. The engine seems to load up a bit at idle, but the RPM's don't always want to drop down to idle from a high speed run. They'll come down, and it will act like I'm giving it just a tiny bit of throttle until I come to a stop, then it will idle, and after about 5-10 seconds start to load up. From a stand still, I have to blip the throttle to clear it out before I have full punch. That seems like the LSN is a bit too rich, right?

The only issue with that, is I don't want to lean anything out any more than it is, because at 91 degrees ambient temp, according to the news, the thing wants to run at 250-260 degrees, sometimes up to 265, and I'm reading everywhere that they run at about 200-230. I've got good power, and good amounts of smoke, but maybe I could be making more? It seems to heat up as it idles, and cool down as I'm giving it throttle, but I'm unsure of what to do. Don't want to risk ruining a brand new engine and I've done plenty of that in the past. Running Byrons 25% with 11% oil content, and I have a McCoy MC-59 hot plug in there right now. I've got some OS A5's I can try, as well as a number 8 "medium" plug.

 

[Greywolf74]

Sounds like its a bit rich on the LSN those temps arent bad as long as you have thin trail of smoke at WOT. you can get them to run around 230 but you have to run them a bit on the rich side. Honestly though if you have the smoke and it doesn't go over 265 then I wouldnt worry about it. if it goes over 265 then Id richen the HSN a bit.

 

[Mr Clickerson]

I was running last night and it ended up getting into the 270 range. The HSN is already 4.75 turns out from closed, and a couple millimeters past flush with the brass collar. I sealed up the engine yesterday but have yet to check and see if the bearing leaks. There's no way my needle settings are anywhere close to being right.

 

[mechanike]

yeah my .28 sh acts the same way.don't fret about your hsn being out so much i have one in a savage with a 160cc fuel tank and its only good for two minutes!what i do with mine is high speed run it and adjust it until it stops june bugging.(don't allow alot of that cause thats a slightly lean condition) i turn out 1/12th of a turn at a time until it just stops doing it then a touch more and its good for a long time unless it drops 20*.its a thirsty beast!!! mine is like two turns out from flush,,,,,,,,,mine also loads up at idle and one turn out or in from flush with the lsn does nothing in my case so i leave it at flush,,,,,,,i 'm going to try a bigger pipe which might help with the loading up,,,,,,,,,,,,,,

 

[Mr Clickerson]

Could all these weird tuning issues possibly be caused by heat soaking of the carb? Perhaps the carb is just a junk design, because I've heard the LRP carb is far better and can be swapped right on?

 

[2revo1maxx]

With that fuel it should be running about 240-250 tops. Richen the hsn until it stops hanging after a wot pass. You can gradually lean the lsn a little more, it'll let you know when you've gone too far by making the "chewbacca" idle.

 

[Greywolf74]

the Losi 454 is a rebadged LRP .28 spec 3 so yeah I imagine the carb would slide right on. The carb however I dont think is your problem. My 454 runs just fine on 20% Odonnell's fuel. Runs in the 230-260 range for me.

The stock needle settings in the manual for the HSN are not correct. I use flush as my starting point for tuning on the HSN and 2.5 TFB on the LSN (I think thats it is the same in the manual for the LSN.)

 

[mechanike]

yeah i like "chewbacca" noise better than "junebug" noise,,,,,,,,,,these guys will steer you right,,,,