If I lean my engine a little further, than it stays into a high idle for 30+ seconds. Now it stays between 15-20 in high idle and then drops to a nice steady low idle.

I'll try the slow throttle method :-) Never done that before actually. I just blip full throttle on the box and listen how clean and how fast it gets to it's top. And how fast the tires balloon

Smaller idle gap ?

This video is your new best friend

Bernard Durand tuning video

Its posted here in the tuning bible

can u explain this please houston. when i let off the throttle the idle stays high then drops down after a few seconds. i have been using the pinch test. i have less than 0.5mm idle gap.

I am 100% against tuning on the starterbox...IMO it is a bad method that should only be used as an absolute last resort when on the ground tuning is not a option......No wonder so many people have issues learning to tune nitro when they are being instructed to tune on the starterbox and use the pinch test on the fuel line, that is terrible advice hat just instills very bad habits..no wonder so many people struggle with this LOL.......

...IMO the only way a engine should be tuned is on the ground under load...............

Most every race in the country has no provisions for on ground tuning Neal , i have found a verrry accurate way of box tuning

Btw 99.9% of all fast guys have to box tune and get there engines very close and only need to get hsn dialed in on the track

Pingy ping ping doesn't cut in my books !!!!

edit.... I mean absolutely no disrespect to you, but too many of the Pro's tune way too lean for my taste..... If a engine comes into the pits and its ringy ping pinging its not tuned properly..... I have no doubt you can tune on the starterbox as I can do it as well.... Anytime we have gone to a indoor event in the winter it has required box tuning...no problem, it can be done...In the end I still feel very strongly that tuning on the ground under load is a much better more consistent method of tuning......

You mean you guys don't use the upside down tuning method?? That's how they do it in AUS. LMAO!

But seriously folks... I've tried to tune on the box but it never worked for me. Granted I'm not the most experienced tuner but I know what's going on. Aren't there usually practice sessions prior to the race? Couldn't one tune on the ground during practice? You'd have to be pretty damn close even if the race the next day has slightly different weather conditions.

I tune by ear and sight sometimes throwing a temp gun on the engine to make sure I'm not too far off. Here are the steps I use, tell me if I'm nuts. I always pre-heat the engine to at least 180° prior to starting and continue to heat it on the box to 200° prior to running. This is assuming the engine is already fully broken in.

• Start with a .7mm idle gap.
• Tune the LSN to achieve a good idle.
• Set it on the ground and tune the HSN for excellent top end with good smoke.
• Tweak the Idle Gap and LSN to stabilize the idle and to achieve crisp throttle response. I like to get the gap down to .5mm if possible.
• Run a few laps or run it in a field to check the tune. Check the temp and adjust HSN if getting too hot or cold.
• Let it EAT!!

Obviously I tweak to the conditions on race days but this method has gotten me very close to a perfect (IMO) race tune pretty much every time. I usually lean the HSN to the point where the engine stops showing top end improvement and then back it off an hour or two. Unlike Austin Powers, I don't like to live dangerously when it comes to expensive race engines. I've never burned up an engine or had problems with pinging or detonation. I've never found tuning to be overly difficult unless there was a mechanical problem with the engine. I chased a flameout problem once for over 1.5 hours just to discover that my inner clutch bearing was toast. If I'm flaming out on a tune that was working well I always start with checking for mechanical problems now.

I agree

If you tune "pingy ping ping" as you call it it isnt right no

So Neil since you have a major issue with a starter box tune can you share your methods for tuning on the track?

I like the Jared Thebo video for base tune on the box and certainly this cannot cover all aspects. I start with Thebo's tune process and then adjust the HSN for smoke on the higher speed parts of the track. Once that looks good then I can fine tune the idle. Since the idle tune is impacted by the HSN setting I feel this is critical.

I do not like the temp gun approach. My Reedy 121VR-ST always runs hotter than most engines which I feel is a measurement error. One race my temp pit guy fattened my engine up cause he didn't like the higher temps and it screwed my power so much I couldn't clear jumps. This Temp guy was a really experienced race tuner and was a hired mechanic for guys here in Brazil. He always wanted to drive the engine temps to a target that was too low for my enginee. You have to get a feel for the tune.

Smart guy Tom , u have a good head on your shoulders

I agree. I only use the temp gun as a safety net. If I'm getting good smoke and have the top end where I want it the gun stays in the toolbox. If the engine runs hot and is performing properly with good smoke I use that temp as a baseline.

just checked the needles on my 28ltr old blue head.

2 1/4 on hs. 5 3/4 on ls. does that sound about right. using 30% fuel. p3 plug. engine temp 220. has tko ceramic bearings. 2090 pipe. idle gap is less than 0.5mm.

the reason i'm asking is that the plug comes out shiny and the coil looks a little collapsed. when i tune it to get the plug golden brown it seems rich on the top end. it also has a two stage idle.

could i be lean on top and rich low. thanks for any help.

What are the tell tale signs bottom end is too lean?

I'm not that experienced at tuning. After running a little rich to break in I started leaning out the HSN and it has great top end with smoke and good temps. When it idles the idle would be high then go low quickly indicating rich so I would lean the bottom, go for a run, repeat, lowering the idle gap as I leaned. What's the sweet spot? I figured if it idled slightly high after a run then settled 20-30s after that would be ok.

But, now my idle feels erratic up and down some times. Maybe I'm too lean now on the bottom?

Thx for the advice.

JJ