Need Help Tuning Alpha Engine
 

Hey Guys,

I am getting fed up with trying to tune my Alpha Ryan Lutz WE and am running out of ideas. The problem that I am having with the engine is that it does not want to be tuned at all and hardly uses any fuel at all. I already went through one Alpha Lutz WE and received this engine from Ryan almost broken in. I have ran 3 full fuel bottles of fuel through the motor already and still the engine is being a finicky little pain.

I have tried changing fuel from VP Powermaster to Byrons fuel and nothing changed. I have tried different glow plugs and nothing. Pressure tested my fuel tank and no leaks. Even did the spray test on the motor while it is running to check for air leaks and nothing to be found. I always run my truggy with a clean oiled air filter. I have checked my clunk, pressure and fuel lines and no blockages to be found and everything seems to flow nicely, but the motor still sips fuel. I read some people getting 10-13 minutes on a tank of fuel, but I am getting like 20-25 minutes on a tank and that does not seem right.

When I get the HSN tuned correctly and move to the LSN/idle this is where the problem with tuning comes. The idle will run on and the drop so I read the tuning bible on here on how to correct this problem and follow the directions. Once I have the LSN tuned in the engine runs like poop. Lean bogs everywhere and engine wants to die coming off of a high speed pass. SO when I turn the idle up a tad to correct this, it goes back to running on and I am back at stage one.

Can anyone please help me diagnose what is up with this thing? Temps are around 270 when hot. I appreciate any help!!!

I suspect it may be leaking air at the banjo fitting. Take the hsn assembly off, sand both sides of the banjo fitting (where the fuel line connects) on a stone or some fine sandpaper on a flat surface. You will see when it is flat and sanded all the way across. Clean it off good and reassemble, I have seen this with a few different brand engines.

how wide are you setting the idle gap?

Rex

Its extremely hard to diagnose on the net but to me it Sounds like your too lean on the high side and your idle gap is too small...double check your gap, making sure that it is no smaller than the width of a standard paper clip or credit card and start over, never touching the idle.

Also, which restrictor are you trying to tune too? I have found that the smaller restricters make things a touch more finicky to get perfect.

I will try that! Thanks for the idea. I set my idle gap at .7mm. A local racer in my area said that my problems sound like a tank issue and to get a new fuel tank. I am going to try both.

Obviously the engine is waaay too lean on top.
Let me just suggest this scenario to you:
First you had fat bottom which was masking a very lean top. Then you set the LSN more correctly. After which the problem of the very lean top becomes more obvious.
Now you are compounding the issue by choosing to adjust idle gap in an attempt to cure the problem.

You might have to open up HSN as much as half a lap or more.

Nobody is a tuning expert right away. Don't give up.
But please do not keep running this engine so lean up top, it is not good for it.

When in doubt:
Richen the high speed needle til the engine blubbers at high speed. Then lean the high speed a little at a time til the engine runs cleanly at high rpm.
This will put the high speed in the ballpark.
Then adjust idle gap to approx .7mm .
Adjust the low speed mixture needle til the idle is consistant.

ALL adjustments should be made with the engine at full operating temp.
(235F - 275F)

I had the same issue with my Dragon. Couldnt get that long needle carb to tune. It was either way to rich or way too lean on the top. Low end was great, idle was smooth and steady and the transition from low to mid was snappy and about perfect. I had several people look at it and we just kept fighting it. I finally put a short needle carb on it and it ran great. Its been 3 gallons and had to touch the needles twice running 10+ minutes in a buggy.

Update: After talking to some LutzRC sponsored racers in my area/state, they said that my problems sound like a fuel tank issue. I pressure tested the tank and no leaks or air bubbles to be found. However, they said it might be leaking on the pickup line inside the tank and not allowing it to drink up the fuel. Kind of the same idea as when you bend a straw and it gets a crack in it. So I ordered up a HB D8T tank and am going to fit that to my truggy once it comes in to see if that fixes it. I had leaks in the AE tank and went to the Jammin X2 tank as it was recommended, but apparently these are no better than the AE tanks. I will report again once I get it fired up.

These guys also said the same thing that they have not had to touch their needles once since broken in on the Lutz engines. Hopefully I am going in the right direction.

I just ran a Lutz (non-worlds) for the first time this past weekend at Wicked Weekend in GA. It was almost broken in when I got down there, and I had a few issues tuning it as well, but I finally got it sorted out.

The longer needles seem to be a little more sensitive than the other Alphas I have personally run. The weather was hot and humid down in GA, so this particular race was a bear to get a base tune down for...and I wasn't the only guy having issues. The HSN was too lean and the bottom was too fat was the ultimate problem. Compared to my other Alphas, the HSN on my Lutz right now is actually @ 2 turns OUT from flush and the LSN is a little IN from flush. Normally the HSN ends up being a little bit IN from flush so in my head I wasn't even thinking it was too lean so I adjusted the LSN accordingly....and then my engine came off it's first 5 min qualifier at 315 degrees with just OK performance. We adjusted for qual 2, but a blown diff didn't let me get a good test on it, next round I hit 310 still with poor performance, and then finally for round 4 we got it pretty close. It was running awesome (maybe a tad fat even) and came off the track at 274 with HIGH humidity and @ 95 degree ambient temp.

So just keep at it. Seems like this particular engine might be prone to being WAY too lean on top and too fat on the bottom to compensate. Just my experiences....hoping it helps you out a little. I think this is the first long needle carb I have had to deal with as far as Alphas go...and I'm run a bunch of different versions of the Alphas.

Good luck with it!

Hey guys wanted to give you an update on the engine. I got my D8T tank in the mail and installed the tank on my truggy. This past Sunday was perfect weather so I went to the track for the afternoon. Motor is now running awesome and tunes like a charm. It was about 80 degrees, sunny, with a slight breeze and my Alpha Lutz WE was running great @ 265 degrees. I kept it slightly rich, but none the less it ran great. No hanging idle or drastic tuning changes. Final needle positions were HSN flush at 1:00 and low speed at about .46mm out from flush. Runtime was about 10-11min before it started running lean from low fuel. Overall very happy!!! Going take it out again this next weekend and really dial it in for the club race on the 13th.