Eng carb. problem
I ran the new motor maybe five times last summer and put away for next summer..
From the begining motor fires up no problem all morning and noon came around the motor sound like running too rich.. I think the low needle started to back out and could be the low jet needle o ring might be going bad...
is this normal ??
I heard some people have to rebuild the carburator all the time??
anybody experience this problem ?
what is the factory setting for the low and high needles?
and what plug number to use and good range temperture deg.

no

Use Josh Cyruls WOT break in method.

Raced my stock .12 STI in my RRR for the 3rd time today and I have to say, that I'm pretty disappointed with it's low end performance. I must be doing something wrong.

First two times I raced it, it spooled up real nice, but it wasn't very fast. In the infield between turns, it seemed to take too long to spool up. It could keep up with other cars on the 250' straight, so the top end seemed fine.

So for today's race, I added a 0.15mm shim (total 0.58mm "solder method" head clearance), switch to 30% nitro (up from 20%), ran a Sirio 6 turbo plug (versus 7), Skyline VR12 Plus pipe, stock RRR clutch setup with the nut at 1.5mm and stock gearing (1st Gear: 16/61 and 2nd Gear: 21/56). The car spooled up a little bit better, but still not fast enough between turns. So I switched to a 15T 1st gear pinion (only thing I had to work with), which gave the car some zip, but I'm still not laying down any serious power.

Any suggestions? What HSN/LSN settings are you guys running?

Thanks

What other glow plug brands can be use on sirio motor?

Ranier:

Much probably, your engine isn't fully broken-in. Mine STi's were a PITA to break in and one needed almost 10 litres to wake up (now is a monster).

I don't see nothing bad on your setup (well... those Skyline pipe... haven't tried, but the stock pipe does wonders, so I stick to it). Switch to a #7 Sirio plug, tried the #6 and #7 and prefeer by far the #7.

For what you're telling it sounds me that your engine isn't fully broken-in and it cannot stretch their legs too. You don't say how much fuel has been thru the P/S but.. looks very plausible to me that still lacks break-in. When broken in, the low end needle on the Sirios needs to be a tad leaner than on a Nova milll or similar, they love to go with the LSN quite lean (how much? easy... if you were adjusting a Nova, the adjustment should be 'too lean' - they need a different approach to adjusting the needles).

Only Sirios, the taper is different and they will leak if you use another plug.

10 liters!! (2.64 gallons)

Hmmm, let's see... 5 tanks WOT on the break-in bench, 5 tanks rich on the track - plus about 4 liters practicing and racing. Looks like I've got to up to 5 more liters to go. DRATS!!

Thanks for the help.

Thanks who sell sirio plus on line?

Around 5 litres, if your engine is one of the latest batches should be completely broken-in, mine were from early batches and came with a lot of pinch.

Do the changes I told you and give it a new try in some tanks, your engine is too rich on the LSN or isn't fully broken-in.

P.D: Just remember to take a look on the conrod! Nobody wants a serious carnage on those puppies.

Lean the bottom end till you hear it ringing then back it off a little. You don't know the tuning limits of your motor until you reach them. If you are worried about your motor, always check the glow plug. It is the only fool proof method to making sure the engine is not lean. If the plug is a little bit dry in the center and wet on the outside then you have a perfectly tuned motor.

if it runs awesome on the track with no syptoms/sounds of too lean on bottom end whilst racing and comes in after 20~30 minute race singing daisy your all good. almost all the sirios at worlds were doing this, the factory guys motors just sounded too damn lean in comparison but they were making some serious power with no signs of fading during the qualifying etc granted they had andrea working on the tuning driver to there motors and who would know the motors better.

Thanks for all the advice guys. If I can't get any more speed by tuning the needles, I may try swapping out that 0.15mm shim for a 0.1mm shim and see if that helps.

Cheers

Just use the stock shimming, I forget the thickness but it is one copper and one silver shim, .04mm? I leave the shimming the same from 60 ft above sea level to 1000 ft and just tune the needles. So far there's only been one track that I've had to play with shimming.

Yes, stock is one copper and one sliver, which leaves a total head clearance of ~ 0.43mm. I'm pretty much at sea level, with the ocean only about 100 yards from the track. Humidty is usually very high here - much higher than in Cali.