Break in settings too lean??

[kx250ryder]

I ran my car (OFNA 9.5 Pro) today, it was about 85 degrees outside here in AZ. Because I hadn't run my car in a while, I put the Cipolla FZR .21 engine I have to factory break in setings to establish a baseline. That was 1/2mm idle, 3 out LSN and 4 out HSN. I did that by tightening the screws until they started to feel snug, and then backed out from there.

For reference, I was running the Dynamite MC-8 glow plugs and Blue Thunder 20% Sport mix.

The bizarre thing is that those break in settings were too lean, and my car was hitting 240-250 on occaision on the temp gauge (orange OFNA one) with the average around 230. I never even hit full throttle with the car, most of that was from driving the car in low to mid rpm range.

I have still been backing down from there, and just finally, after probably a half turn extra (or more) out on the HSN and LSN, got it below 200.

I had assumed that because it was warmer here in AZ that I would be leaning it out like crazy to make up for the air thinning from the heat. This seems like exactly the opposite. Any ideas?

Side note: I cannot get the engine to idle low enough to make the car sit still, I have to hold the brakes to keep it from idling away. I am running a standard clutch bell, with blue aluminum OFNA shoes and the gold springs that came with the shoes. Is this where drilling out clutch shoes comes into play?

 

[CorradoPsi]

your engine is shimmed for 30% fuel, use it, and lose the blue thunder brand if you can. trinity, odonnel, sidewinder, maxys, rocket science, byrons, racers edge are all high quality fuels i would use. try finding something with 10-12% oil in it. during breakin using the heat cycle method i would not be concerned about temp ranging from 200*-235* if it gets higher than that, i richen up the LSN. if you have a high idle even after richening up the LSN, you can use the idle screw to close the carb opening a bit to slow down the engine. a high idle will also contribute to your high temps.

 

[kx250ryder]

You have jedi like R/C skills Corrado. When I get a chance to stop by my lhs, I will pick up some 30% fuel from one of the brands you suggested.

I had to tune the car even richer still this evening (before I got your post), I hope that your fuel, LSN and idle settings can get the engine running cooler.

By the way, where did you find the recommended fuel for the engine? Or if you tell me will you have to kill me? :sniper:

 

[bsodmike]

He'll just go "You will not remember" and wave his hand...

 

[psunitro]

A lot of mills are shimmed to accept 30%, you can run 20%....but you can run 30% safely. Yeah, Chris is a Jedi Master Tuner,had my Storm singing a sweet tune after a few min. and a few roll-overs.....HMMMMM......Jedi Master Tuner.........maybe you will now be known as JMT........

 

[CorradoPsi]

jedi master i think not, more like spaceball swingin my shwartz around. the fuels i recommended are "higher end" than the blue thunder your using now. blue thunder is considered a beginner fuel, they add stuff to it to try and keep people from leaning out thier engine too much. however I've never liked the way it burns. i like clean pure fuels like those i mentioned. some of them run a little hotter than others, sidewinder for example has a little more oil in it, with a higher concentration of castor than some of the others. it makes good power, you just need to get used to it running warmer. rocket science is the coolest burning fuel I've run yet, and i hear byrons race formula behaves similarly.

 

[mikeburgin]

May the swart be with you corrado
whats your fuel worth a ltr over there corrado

 

[CorradoPsi]

we dont buy in liters, its quarts or gallons. a typical quart goes for 10-11 bux and a gallon goes for about 30. this is in LHS's, i bought a case online that worked out to $22/gallon shipped.

 

[kx250ryder]

Crap, I went and got a gallon of 30% O'Donnell, like you suggested Corrado. I did a little research (too late!) and realized that my LHS only carries their sport mix, and not their race mix. Will this still be ok?

This is what I got:
http://www.duratrax.com/caraccys/dtxp0710.html

I still have the Dynamite MC-8 (medium range) glow plugs. Should I try something else there too?

 

[CorradoPsi]

that should be ok. plug will be fine too. continue breaking in. richen the lsn if needed.

 

[kx250ryder]

Well, I ran the 30% fuel, and the strangest thing happened. At my house I was up to like six turns out on the high and three out on the low, while still running with the temps between 230 and 250. Air temps outside were about 95 yesterday, so it was hot. I drive to my buddys house, same air temps there only difference is that its slightly cloudy now, start up my car, temps are at 160, and the engine is blubbering rich. I made no changes to jetting. My engine temps dropped almost 100 degreees???!!! I had to go back the other way by two turns on the HSN and it was still rich.

I came up with two possibilities:

1. I may not tighten my glow plug enough normally. When I got to my buddies house, he told me to tighten it as tight as you possibly can. I am usually a little paranoid to do this (don't want to strip the engine threads), but I took his advice. Would this make the engine cool down and run richer?

2. My glow plugs are shiny on the outside, and this may throw off my temp gauge. My buddy and I both have the orange OFNA temp gauges, but his dull colored glow plug temps between probably +-5 degrees. My temp gauge will jump back and forth between 190-250 on the same check! Does anyone else have this kind of back and forth fluctuation when temping?

Oh yeah Corrado, this is not break in, the engine is not new.

 

[CorradoPsi]

a loose plug will cause temp and tune changes, though it shouldnt be gorrilla tight, just enough to seat it properly. the copper gasket should be slightly deformed when you pull it out, this means its conforming to the head and plug and making a seal. it sounds like your temp guage is dirty or out of calibration. make sure the lens is clean.

 

[kx250ryder]

Corrado, the aforementioned buddy of mine wanted to know if the 30% you recommended for me will work in his Orion WASP .28. I had him try some, and it seemed ok for the tank he ran, but he wanted to know if any head shimming will be required, or things of that nature, for proper operation in the long term.

While I am here, I noticed that when I was running my car last, that when I would let off the gas from mid to full throttle, the engine would drop below normal idle level, before picking back up to regular idle settings. I was thinking that this meant that the low end was too lean because the crank was taking a second to get fuel back in it, but when I pinch tested it it was like 7-8 seconds before it would die. So I don't know.

Teach me how to use the force for jetting Corrado. Hah! (sorry it is against my religion to use AOL like abreviations for laughing).

 

[CorradoPsi]

well its nothing i can teach quickly, especially over a computer. but i can certainly give you tips when needed.

yes your friend can continue to use 30% no problom. what temps is your engine running now. how does your engine sound at WOT? is it blubbery still, or high pitched and raspy? your LSN obviously needs leaned out to the 5 second range. i suspect the HSN is rich too, and when you let off the gas the extra fuel momentarily floods the motor.