Half a turn in from flush top and bottom. Idle 1 1/4 in from just closed.

I gotta start over. My Full Mod is running alright but I don't think it's running like it could or should be. It's hauling my truggy around with good authority but I saw a race prep go today in a buggy and that had me asking questions. It sounded angry and it ran down my MTE and that thing is not slow. Honestly, it flat out distracted me while I was trying to drive. After the race I found out that angry sounding stupid fast engine was a race prep.

My setup: P5, RE10 Pipe, 30% Byrons

High Speed needle is 2.5 turns out from bottom or half a turn in from flush.

Low Speed is 3.5 + turns from the bottom or 1 1/4 in from flush.

I put a new plug in a few tanks ago, it currently has a shiny bronzed look on the face, the coil is greyish red, looks shot and the glows weak. These things are getting expensive...

I notice when I go to pit the engine is idling high, like the low speed is lean or my idle gap is too big. This only happens when I have the engine hot because I am worried about it flaming out when I am warming up the motor on the box, it's from one extreme to the other. Temp wise I am around 240 on my gun, for what that is worth. I feel like it's the low speed being too lean but only a few hour turns ago I was told I was too rich, pulling filaments out of plugs, browned plug faces, and flame outs. Now I might be too lean. My fuel mileage went out the window too, I needed to stop twice in a 20 min main. Two weeks ago I stopped once and still had fuel to spare. I am lost in the sauce here! Granted I am not flaming out and my truggy is jumping everything with ease, I know something is not right. This all stems back to a race prep blowing the doors off me and my Full Mod ain't turning heads like it should.

Is it normal for these engines to be very cold natured on start up? I have a race prep in my truggy with the 086 pipe, P4 plug, EB Mods 30% fuel and it takes at least three or four starting attempts for this engine to actually run. It will fire up and run for a few seconds and cut off. I literally have to start trying to start the engine halfway through the previous race just so it will run when my race is up.

Never had any of these issues with my Ninja JX.21 engines. Ideas?

Are you reffering to mine? It took me a lil while with help from Ed and Joe to get it this way. I always had Italian motors. The JS seems like it prefers more adjustment on the low end needle. I always pit at 10 min too.

Ill have a full mod soon-cant wait to feel that!!

I am having the same problem

^ Mine is cold to start too, same thing. ralleybmx, if you were the guy with the orange wheels in pro buggy at the Hut today, I am talking about you. That thing was nasty. Honestly, besides Steve running that .28 Rossi in his truggy your engine was the baddest out there. At this rate, my engine is going to be junk by the time I get it tuned right because you're race prep is like twice as fast as my full mod. How is this possible??? For now the compression is good enough that it will pass the 3 o'clock test with flying colors. I'll throw some more P5's at it...For now I am going to put the JS in my buggy because the mileage sucks on my Orion. A little bit of a rant here but I am sorely disappointed that I can't figure out how to get my engine tuned right. Good racing by the way! You coming back to the Hut any time soon?

Yup, I have the orange wheels. This engine tuned so differently for me than most others. Your full mod can be even nastier than my race prep. I tried one for a short while this year. I didnt even have it fully tuned and man, it spooled up so quick!! Hopefully this week Im full mod again. I live in State College so its a bit of a trip for me there. I'll definitely be back a few more times though

so i keep reading that these motors tune SO differently than most other motors on the market. how is that? i mean a carb is a carb the HSN is your main source of fuel and top speed, and your LSN is the source of acceleration. is this motor somehow different than that? or am i just reading these last few post of the people having a few problems right now.
im thinking about getting one but maybe not if they are so different. someone please set me straight here

I thought my full mod was fine until I saw a Race Prep go. You have to understand, I am not doing bad with it. It's making my truggy do everything I need it to and more but now I realize I don't have it right. I don't know what else to do, my temps are getting high, I feel like it's lean bogging a little when coming around a slow turn (= low speed too lean, my best guess) The High speed has been too rich so I have been leaning that. I am hesitant to lean it anymore because temps are climbing. I think this engine is great I just need some help with it.

your HSN is too lean. back off till the "slow speed bog" goes away, then start leaning the bottom. idle is also prob to high if you touched it at all.

Joe, the HSN is one half turn in from flush, it blubbers and almost doesn't clear out on top if I go any richer on it. We're talking dog slow spitting oil everywhere. I have found the bog with the HSN before and that was like 2+ full turns in. I have not touched the idle screw, idle is not high when the engine is warming up for 4 to 5 mins on the box. I actually have to keep it from stalling for the first few mins. It does start "racing" after I am racing for 8 to 10 mins and come in for fuel. Ballpark figure here, how far in should the LSN be from flush on a Full Mod for a good tune? Mine is currently 1 1/4 in.

That is operator error and improper diff shimming, not the engines fault.

sounds like the balance is off on the tune. lsn should be just in from flush and the hsn should be in about 4-5 hrs. here in the south we have EXTREMELY high temps and HUMIDITY. i have had good luck with adding a
.004 shim (copper) and the p4 plug. helps with opening the TUNING window alittle bit. you can try the p5, with the SIDEWINDER STRYKE TEAM fuel it worked fine also.

engine is alittle cold natured leave the glow igniter on for the first minute or so helps bring the heat up in the engine alittle quicker.

That's where I started, HSN in 4-5 hrs with the LSN in just a little. I was pulling coils off of brand new plugs, flaming out on the pit ramp, loading up, absolutely no low end. I leaned the bottom out and plugs are lasting longer now but I am still chewing them up. I have destroyed something like seven P5's and at $8 a plug it's killing me. I think my only option is to lean the LSN more and if it idles higher, turn the idle down...

This past weekend we raced 5th round of the North Carolina Championship Series. My son finished 2nd in the 1/8 buggy A main with his JS engine and EB Mods fuel. He is the current points leader with 1 race to go.