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Old 04-18-2009, 06:06 PM   #1
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Default Tuning help appreciated

I already posted this in the Monster Truck forum, but they said to come here.

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Anyone have any tips to get the bog out of the bottom end of my engine?

It's an LRP Z.28R Spec 3 in an Associated MGT. I have the high end figured out and it flies but it bogs pretty badly when coming off of idle. I tried leaning it out ~1/8-1/4 of a turn on the low/mid needle and it started not being able to hold an idle, went the other direction and the bogging just got even worse.

I am running 20% Traxxas Top Fuel with the stock gearing, and as I said earlier, once it is moving it just flies, but down low it is just annoying.

I have about a gallon on the engine, it still has an insane amount of pinch, and when I take the temp it hovers around the 210 degree range.


Any help is appreciated."
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Old 04-18-2009, 06:10 PM   #2
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When you leaned the low speed needle did your idle get higher? If it did lean the low speed needle end out by 1/8 of a turn at a time and also lower your idle by twisting the idls stop screw counter clockwise.
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Old 04-18-2009, 06:23 PM   #3
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It didn't get noticeably higher, just choppier until it bogged out. I'll try leaning it out though, see if that helps.
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Old 04-18-2009, 07:45 PM   #4
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Your fuel is the problem.....IMO the best are Nitrotane, Byron, and Sidewinder.
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Old 04-18-2009, 07:49 PM   #5
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It actually could be the fuel, not because it it Traxxas (but once it gets closer to summer I'll switch to Byron's), but because this gallon is about 5 months old, and it was stored in a fairly cold area.


I'll crack open the fresh gallon tomorrow and see if that makes a difference.
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Old 04-18-2009, 08:23 PM   #6
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also i think top-fuel has a very high oil content but idk what that would do. I really just thnk its a tuning issue.
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Old 04-18-2009, 08:41 PM   #7
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I also think it is a tuning issue, I'll lean out the idle tomorrow, but in very small increments, see if that helps.
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Old 04-18-2009, 08:44 PM   #8
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if tuning doesnt help switch to a stiffer clutch spring and make sure the clutch bell bearings are in good working order.
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Old 04-18-2009, 09:13 PM   #9
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Get some Byrons Gen 2 25-30%, lean the bottom, add 2 thicker clutch springs and keep one stock, run Dyn max lifes.
I raced a full cf shassis LST2 with a LRP Spec 3, still have it actually, thinking about selling it as I run Z-Car buggy and soon to be truggy now
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Old 04-18-2009, 09:18 PM   #10
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Looks like I'll be heading to the LHS next weekend, or might just order everything from Tower tomorrow, can't even run it right now, stupid screw came out from the steering while running it.
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Old 04-19-2009, 03:02 PM   #11
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Also, what size glow plug does the LRP take?
I searched around and couldn't find a definite answer.
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Old 04-19-2009, 03:11 PM   #12
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you can run mc 8,9, or 59. I always ran mc 59 in my LRP .28
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