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Running lean with a turbo

C
Jan 24, 2017
31
2
8
We are running a 2014 pro rmk 800 with a silver turbo. I bought the kit used and it runs great. I noticed the spark plugs are gray and figure it is way lean. Will turning up the oil pump or adding oil to the tank help or do I need to get something done with the ECU to change the Air/Fuel ratio?

Thanks,
 

ez-ryder

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Nov 26, 2007
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Is this a reflash ECU kit?
Fuel to oil ratio is different from air to fuel ratio.
adding oil to the tank will in theory lean it out further in respect to air fuel.

I'm not schooled on this but which ethanol mode is it supposed to be in.
Was a new fuel filter installed with the kit?

but make sure it's using a healthy amount of oil. calculate gas used vs. oil in the tank. they run pretty lean from factory.
I turned mine up as much as I could with the stock set screw. it's in the 50s to 1 range with a stock cap.
I also run 100:1 in the tank because Indy Dan says to.
 

05rmksteve

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Did you put the proper injectors in, is the ecu flashed for the turbo and did you install the map sensor for the turbo?
 
C
Jan 24, 2017
31
2
8
Is this a reflash ECU kit?
Fuel to oil ratio is different from air to fuel ratio.
adding oil to the tank will in theory lean it out further in respect to air fuel.

I'm not schooled on this but which ethanol mode is it supposed to be in.
Was a new fuel filter installed with the kit?

but make sure it's using a healthy amount of oil. calculate gas used vs. oil in the tank. they run pretty lean from factory.
I turned mine up as much as I could with the stock set screw. it's in the 50s to 1 range with a stock cap.
I also run 100:1 in the tank because Indy Dan says to.
We did install a new fuel filter. Oil is turned up on the sled but I couldn't tell you how much. I've always heard the ethonal mode run's richer so I can try that. The ECU was sent to Silber to be flashed for the turbo.

Thanks,
 
C
Jan 24, 2017
31
2
8
Did you put the proper injectors in, is the ecu flashed for the turbo and did you install the map sensor for the turbo?
Running the injectors that came with the kit. The ECU is re-flashed and we are using the Map sensor that came with it as well. I think I will try the ethonal mode.
 
C
Jan 24, 2017
31
2
8
Started with 3lb because we just did a complete rebuild on the motor. After 100 miles put in 7lb spring. Running AV gas. 3000-6000 feet.
 

05rmksteve

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I know 110-114 race gas mixed with 91 will burn different and show differently on plugs vs straight 91. I have not ran av gas so I cant tell you how to read plugs with av gas. I also run a 7 psi spring on my silbert turbo pro rmk but to be honest I've never really looked at the plugs in 3 yrs now because plug readings can be inaccurate with boost and fuel mixes. Did a top end leak down test at the end of last season and I was at about 2% put plugs back and have been running it this season. Deepening on altitude I run 110 or 114 mixed with non oxy 91 at 25%75% at 10,000+ and 35%65% at 8,000+.
 
Last edited:

Octanee

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Pretty sure your seeing the gray from the lead in the av gas. It changes the usual plug wash coloring.... If it's not throwing its self DET codes you may be just fine.... If your honestly curious then buy/install an air fuel gauge, then you KNOW.
 

Sheetmetalfab

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Pretty sure your seeing the gray from the lead in the av gas. It changes the usual plug wash coloring.... If it's not throwing its self DET codes you may be just fine.... If your honestly curious then buy/install an air fuel gauge, then you KNOW.

Until the lead ruins the AF sensor. :)
 

Octanee

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Until the lead ruins the AF sensor. :)

that and the burned oil from a 2 stroke ruins the o2 sensor as well.... they don't last that long in a 2 stroke, many variables. I found I was ~ 1 every 1000km ish IF I wanted it to respond like new, After that it became slower like "lazy" which didn't matter when the sleds tuned. But if your wanting to know what the sled is doing you can install the o2, check it, Then remove it and leave it at home. A/F will be different as well depending on fuels and how much of it you run as it will change it. It may read richer than it really is, or leaner.
 

madmax

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You don’t really know if your lean or not until you either set off the set sensor, melt a piston or install an O2 sensor. Like said before, if your not setting off the det sensor, you’re most likely ok.
 
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