OS 21VG Tuning issues

[MotoGod]

I ran my Truggy at the track yesterday and couldn't get the temp under 260ish for the life of me. I managed to do 5/6 laps, then pulled in for a temp and it was up @ 260-270. I richened the HSN up a bit, did another 2 laps and the temp came down @ 5 degrees, so I kept going like that for maybe 8 laps or so. Got it down to the 250 range and needed a refuel. Fueled up and the motor simply refused to fire. Took out the plug and it was dead. Glow Ignitor (tried 3) wouldn't even make it glow at all and there was a black spot at the tip of the wire. I assumed that was an "Oh shoot you're lean" reading.

So I tossed in one of my spares (MC59) and it fired right up again. Kept tuning for a few more laps, richened @ 1-2 hours at a time. Killed another plug in a few laps. Replaced it again, only the motor refused to fire this time at all. The richening was also making the motor run like complete crap. Bogging and loading up all over the place. I actually had to lean the HSN back by @ 4 hours before it finally fired up again.

I'm no pro tuner, but man...I could have SWORN I understood everything needed to tune a motor. The only thing I can think of is these MC59s are simply too hot and mess with a tune. The really strange thing is I burned a good 5/6 laps when I first fired up the Truggy at the track and it was running MINT. Plenty of power...nice trail of smoke...no bogging or loading. Then I temped it and nearly shaat myself. lol If the temp was lower initially, I never would have thought twice about it. It was running that good.

I'm having near identical issues with the 21 in the Buggy as well, except it's not blowing plugs, just running 250ish without really hammering on it.

Anyone have any ideas here? I don't want to ruin the motors by running em too lean, but I can't seem to get the temps down, and there don't appear to be any air leaks, but I have not ruled that out just yet.

Running O'Donnell 20% Nitro in it. First tank was the last of my Trinity Monster Horsepower 20%.

 

[Scrogg]

Put some good 30% in it and try a MC-8. The McCoy 59 and 20% should work though. You did say this engine only had a few tanks thru it right? Maybe the mechanical pinch is still there causing your excessive temps. Pull the plug out and rotate the engine over and see if it feels smooth when the piston hits TDC. If it feels like metal on metal at TDC, it still needs more break in.
Last one I had my hands on was running very cold on Byron's 30%. These engines usually run hot, too hot for their sleeve to handle.

 

[MotoGod]

8 tanks on it now. I wasn't beating on the motor either. Just some easy laps with all different throttle positions. LOTS of time under 1/4, a little at 1/2 - 3/4, and only 2 spots on the track wide open for short bursts.

It's very possible that it needs some break in time....which I thought of as well. So I'll idle a few more tanks through it...or drive it easy and see what happens. I had a clutch problem before I really got into my testing session with it so you know how that goes. New clutch going in this weekend....yay.

 

[Scrogg]

No idle tanks, just keep driving her like you are.

 

[MotoGod]

I'll see what happens. My buddy drove my Revo in the yard tonight and loved it...so I may try to get him out to the track Saturday with me. We shall see. If I can convince him....then I'll be there ;-)

 

[Scrogg]

I'm going to the Farm Saturday morning, another local buddy is riding up with me.

 

[MotoGod]

Very nice.