They deal with mowers and that, so didn't take it to him..

But I had success.. Opened the bottom needle a little more to just over one and a half and with the new plugs, bang of they both went.. And boy you notice the difference...

Fiddled with the timing a little and found it made little difference. Started at 30 degrees before tdc, took it all the way over to 50 degrees before tdc and it ran a little rough but still ran..
But if I went to say 20 degrees before tdc it stopped running on 2 cylinders..
So sticking at 30 and tuning properly once I have it hooked to servo's and can control the throttle..
So yea, I'm happy now.. Now I just have to re weld the exhausts due to pin holes galore...

I have a new BME 150 lt and I need a little advice.
I finally have the engine running pretty well except there is a dead spot, not really a sag, (or maybe I just don't recognize it as such) from about half throttle to full. Smooth transition from idle to half. When the throttle is advanced rapidly from idle to full, the engine just holds rpms from about 4,500 for about 2+ seconds, it clears and then screams at about 6,000, no sagging after that.
I'm running avgas with Stihl Dino at about 40:1, mejzlik 30/10-2blade, MTW cans, cowl off at this point, no flights yet, just ground run.
Where do I need to tune?
Thanks,
Asher

Is the motor still being run in?

Originally Posted by BigK

Is the motor still being run in?

Yes, Branny new, about 1/2 gallon thru.
Asher

When you say clears, does it sound rich or lean?? If it is not spitting and coughing but running smooth at that 4500 mark for a few seconds it is lean.
Is the throttle plate opening the correct direction??

Originally Posted by RTK

When you say clears, does it sound rich or lean?? If it is not spitting and coughing but running smooth at that 4500 mark for a few seconds it is lean.
Is the throttle plate opening the correct direction??

Lean on the high end?
The throttle plate direction appears to be governed by a spring on the control arm and the throttle action is "opening" when advancing the stick. Not sure how it could open the other way. I guess the lever arm could have been put on wrong at the factory, allowing the plate to rotate 180 degrees. How can I tell if the plate is in the right position and opening properly?
When I richen the top end about 1/8 turn, the engine won't go above about 4,500. Too much adjustment, maybe? I've heard BME's can be sensitive.

Definitely sounds rich if when you richen the high end it won't go above 4500rpm.
Righty tighty lefty loosey, correct??
The throttle plate should close and cover or almost cover all the low circuit holes in the venturi, then open to wards the high circuit outlet. You should be able to the the thread end of the throttle plate screw and not the screw head when the throttle is closed viewing from the choke side.

Ultra short carb tuning guide:
Set the engine to very fast idle. Turn the needle closest to the engine until you find best rpm. Back off 1/16th turn. Rpm should still be about best.
Go to full throttle, and tune the needle farthest away from the engine for best rpm.
Use a tach to read rpm!
Now adjust the low needle (if needed) for good throttle response when quietly advancing the throttle. When horsing the throttle (which you should not do), a very slight stumble is acceptable

I love horsing the throttle Pe, and you are right, when perfectly tuned you will have a very slight hesitation if you stab the throttle from a very low idle. Most of our poor little carbs don't have an accelerator pump....anything above a low idle mine don't stumble.

Thanks to all,
I've done some tweaking and it's doing what it should! Now I just need to fly it and then make final adjustments as the engine settles in. Thanks again.
Asher

Originally Posted by pe reivers

Ultra short carb tuning guide:
Set the engine to very fast idle. Turn the needle closest to the engine until you find best rpm. Back off 1/16th turn. Rpm should still be about best.
Go to full throttle, and tune the needle farthest away from the engine for best rpm.
Use a tach to read rpm!
Now adjust the low needle (if needed) for good throttle response when quietly advancing the throttle. When horsing the throttle (which you should not do), a very slight stumble is acceptable

Nice short guide, but ya forgot step #1, the most important step;
First, run the engine until it's fully warmed up BEFORE ANY tuning is done!

Then a foot note; once properly tuned, when cold it may show a wee bit of hesitation in transition until warmed up. Don't be glow tuner & start fiddling with the needles again. If you already had it tuned well, just let it fully warm up & go fly!

I hate endless needle fiddling tuners.

I will be following this tomorrow arvo. Just some questions though? When you say a fast idle, 2000 rpm'ish? And am I looking for a smooth idle at that speed?
Cheers

Originally Posted by a1pcfixer

Nice short guide, but ya forgot step #1, the most important step;
First, run the engine until it's fully warmed up BEFORE ANY tuning is done!

Then a foot note; once properly tuned, when cold it may show a wee bit of hesitation in transition until warmed up. Don't be glow tuner & start fiddling with the needles again. If you already had it tuned well, just let it fully warm up & go fly!

I hate endless needle fiddling tuners.

You are quite right. All those little things you do without thinking. Have to switch back my thinking to the time I was that newbie that never did it before.

Originally Posted by pe reivers

You are quite right. All those little things you do without thinking. Have to switch back my thinking to the time I was that newbie that never did it before.

I just remember how a hedge trimmer, weed eater, leaf blower runs until warmed up.
They like ours, run fine when warmed up (and tuned correctly).

I was wandering if someone can help me out.

I have a DLE30 and it has been working fine for the last few months.
but i haven't flown it for around 1 month and when I startered it today to started without any issue and it idled well without any problems.
the problem is when i increase the throttle the engine will dies. I checked all the main snags (full tank is full., no bubbles in the fuel line, ignition battery is good. spark plug is good)

i haven't touched the needles yet since the engine was working fine earlier.

can someone help me