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Dynamite big red .28 tuning after fuel brand change

kelly2727

Member
Messages
12
Okay so I have a dynamite big red .28 in my savage X and it’s been just fantastic. UNTIL I ran out of my usual fuel that I use witch is sidewinder 20% nitro 12% oil and bought a gallon of VP 25% nitro. My engine was running absolutely perfect the same day I bought the different fuel. I went and bought the fuel at my local hobby shop witch is a 10 minute walk from where I live. I got home with the new fuel and drained any last little bit of the old 20% From the tank and lines. I got everything all ready to go again and filled the tank with the new 25% fuel. (I figured I was going to have to do a bit of tuning because of the difference in nitro percentage) The truck started 1st or 2nd pull (as always) And I let it sit and idle for about 30-45 seconds and I noticed it was spitting an awful lot of fuel and oil out of the exhaust at idle. (And I mean A LOT). So after it sat at idle for a minute or so I go to hit the throttle and it immediately dies. So I start it again and it’s idling absolutely perfectly so I hit the gas again and it dies again. I try and start it again and at this point I had obviously flooded the engine So I took out the plug and drained out the fuel in the combustion chamber and tried again. It starts, it idles, it dies when given throttle, and then floods again. So this time after draining the excess fuel when I go to start it I give it a little gas on the transmitter to get the wheels going so it would drive around And it did just that. But it would not pick up RPM at all. As if I was trying to accelerate from 0 mph in 5th gear in a standard vehicle. It eventually started to pick up a little RPM and gain a little speed (not much). After I would get it to higher RPM and came off the throttle it would rev high for about 10 seconds more or less and then the idle would be okay until I tried to accelerate again in which it would die. This has been driving me crazy. Because it’s like it’s too lean when I let off throttle but way to damn rich when trying to go from stand still. Finally after Messing around and failing over and over I finally just started to lean out the LSN an 1/8 turn and then go for a few laps in a circle. I did that about 4-5 times and it finally stopped wanting to die instantly when given throttle at standing idle. By that time it was about 10:15 and people in my area were probably getting as irritated at me as I was with the truck. So I just it down for the evening and here I am writing this to you guys wondering if anyone has ever experienced this as the result of changing fuels/nitro%. I figured I was going to have To richen the entire system to keep it protected from higher nitro content. But it had to be leaned out. Like a lot. I even reset my carb to factory settings in all the diagnostics and it was still acting rich at take off and and lean after high RPM. So tomorrow I’m going to start to richen the HSN. I just want my savage ass savage back to good health :(.

PS......AFTER I WAS ABLE TO GET IT TO PICK UP SPEED AND RPM I COULD STILL HOLD MY HAND TO THE HEATSINK WITHOUT BEING BURNT (I’m buying a temp gun tomorrow)
 

Jabbo

Member
Messages
20
LSN too rich, HSN too lean. Pinch test the low speed needle first, then start adjusting HSP. Factory settings are good for starting point.
 
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