Hey guys, just wondering how to get decent fuel economy out a P5XL which has been running 25% Neo+ fuel since break in.

Have put through just over 4 litres now and it's turning into a beast, even when rich, but just scraping the 7 min run time required to get through the heats.

I'm running a 41020 manifold with an SS 9901 pipe

Is it worth investigating the different insert sizes or consider leaning LSN and HSN?

wheres the crank

15009t crank , like older plus 21-4 buggy and T had

Hmmmm no bypass ports

Put a 41021 or 41005 header on it , richen your hsn up and lean your lsn , guarantee your lsn is too rich . That is the #1 reason for bad runtime for most all engines

Houston, you seem to be a big fan of the 41005. I am too and I have one but I recently have moved away from it because it seems to be a more suitable header for hi bite tracks to ME because of its abruptness. My home track is super loose so thats why I no longer use it on this particular track. Whats your thought on this?

I personally always run a 8mm or smaller carb insert,running a 6.5mm on my Maxys Cinco Tuned Nova motor.

I haven't really touched the LSN much, would be lucky to turn it much and the HSN is close to flush

The main reason for the 41020/9901 combo is that I'm still learning how to drive in general.

What is the expected run time I should expect out of the engine? 9 - 10 mins?

For the nova 28/7t what is the optimum insert?also I'm starting to wonder if these motors are popular?seems to be many 21s running but not much on 28s? Any info on my problems is greatly appreciated

Try putting the low speed needle flush and open the top a little bit out from flush then slightly lean it till it's running strong. I run a 7-7.5mm insert. 7 smaller tracks and 7.5 bigger tracks. with that setup, pipe, you should get at least 7.5-8.5 minutes. Wait, is this in buggy or truggy? In a buggy I would use the 41021 or my favorite the 41001. In truggy don't ask me. I dunno. I know guys brag about getting over 10 minutes but I don't see that too often in real life but it happens quite often in fairy tales.

This is on a Losi 2.0 buggy (soon to be 3.0). I did play around with the HSN and turned it about 2 -3 mm and the LSN a fraction also, gained maybe 30 seconds.

But that might not have been a true gain though as I was driving differently in each heat.

Full bore in first 7 min heat, more controlled in the second 7 min heat, and ran a two stop strategy for 20 min final with a little fuel left

Alll depends on what pipe you use it on for one but yes it does make an engine get on the pipe quicker for the most part , I use it with 9853ss mostly , funny thing is it smooths tbd 9853ss out but on many of the top end pipes it almost does the opposite . Completely disrupts the scavenging loop in comparison to the 41021

Is this it?

I run it on a 9886 and its exactly the opposite you mention. How is it on a 9901?

Nobody use the 2096 pipe anymore?

IMHO the 2096 is the top pipe for racing buggy. I tried the 9901 but felt it choked the top end a little to much on the plus 4. 2096 leads to a very drivable power band and good fuel mileage.