100XBL start failure
 

I have a Merlin 100XBL purhased Dec. 2015 Sn 132650. I test ran it right after receipt and test run was OK. Today I tried to start it and the kero never lit. I have run a lot of propane start engines but this is my first Kero start. The starter runs it up to 4000 rpm and then it fades down to approx. 3000 over the next 45 seconds but kero never lights.
Looking for suggestions.
Sid Gates
720-346-7970
P.S. I tried a new battery 2S lipo and another battery that works OK on Propane start engine using a very short lead from battery to ESC.

Are you sure the pump is running? I think that is in the time frame where there were mixed results with the JM pumps.
Try priming the system to be sure fuel is moving. Also a battery that works with gas can be useless with the load from a kero start turbine.

I had the same problem last weekend, with a 100, I removed the fuel line from the turbine and did a test run of the pump using the data terminal. I ran the pump for about 30 seconds. After that the turbine fired up just as expected and work without issue for the rest of the day. The other thing that I have done on other Jets Munt turbines that have had this same problem is in the start/startup parameters menu is to increase the Pump Pw Ignit. K value. I have increased this from 125 to 375 on one turbine and now starts fine. If you start to increase this value do it in 25 % increments only since if you go to fare you will turn your turbine into a flame thrower on startup.

Robert

Start Failure
 

Thanks for the quick suggestions. I think my regular battery should be adequate, it is 5000mah 2S Lipo. I went to the large battery because I needed nose weight. I will certainly try a different battery. I did test pump fuel manually but not very much because I can only see the fuel line a shorty distance from the pump. I didn't observe fuel flow during the start attempt, will do tha today.

After thinking about it more the decaying RPM that may indicate inadequate battery even though it is new.

Test Today
 

Test start with voltage monitor. Battery checks 8.1v no load. 7.9 with heater on and 7.6 when starter kicks on. No kero ignition. RPM starts at 4000 decays to 3000 then "ignition failure".

Sid,

Either your heater/burner has failed or you're not getting fuel.

Did you fully purge the fuel lines? After sitting that long there's probably a lot of air in the lines. Disconnect the fuel line from the engine and route it to the ground or into a container. Run the pump until you get a steady stream of fuel and no air. Reconnect and try a start. Use a clear fuel line so that you can see if fuel is moving during the start.

After initiating a start it should say "Burner On" for 5-10 seconds. If the burner is working you should hear a slight humming. If you put your hand on the case during that phase you should feel it getting slightly warmer, plus the temp reading should go up a few degrees. If that's not happening you'll need to send it in for a new burner.

Thanks Joe, will try your suggestions tonight. It shows burner on and I can hear a different sound at that time. Do you think my RPM is normal for start?

Yes

That helps to know that. I am used to propane start where rpm is near 10K.

There's a pretty good explanation of the start sequence in the users manual. You might want to read through it before attempting your next start. Be careful that fuel has not puddled inside the engine during a failed start. If you've pumped fuel into the engine and it doesn't start, then you need to position the engine NOSE DOWN with a rag or paper towel at the inlet to drain out the fuel, or your next start might result in a flame thrower.

I found a missed start on a JM 100 to have soaked the burner easy , and has to be waited to dry out.
also found the kero start burner runs much happier on a 3s life battery, the ECU auto detect the battery, no settings to adjust and the ignitions are much better. 9.9 V

Hi Sid, it sounds like you may just need to adjust the igniter voltage and or the pw. Are you getting white smoke from the exhaust before it fails the start? Just a something to check look at the rear of the motor during the initial start you should see the glowing from the ignitor.

Start Problem
 

No white smoke. The good news is my engine started 3 times today. I made a short ext. lead to go from the Multiplex connector on the ECU to a Deans Ultra on my battery. The 2200mah Lipo battery lead is approx. 6" long. Next I moved the Lipo to the nose where I wanted to locate the battery for balance purposes and the starter would not kick in This lead is approx. 2.5 ft long. Before I had tried to start with a 5000mah lipo in the nose using the 2.5ft. extension with no starter action.

I have concluded that a 2S lipo is marginal for this engine.

3s life
 

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Fender- Can I use a 3S LIFE on my engine? Is that approved by Xicoy, maybe I should ask is it approved by Merlin?
Sid,

I have a Jets munt 140 and have had to do this several times to get it to start. The first start of the day is not successful and I could hear the pump motor running but not very fast. I have even put a black mark on the end of the armature that sticks out of the motor so I can see it turn. I would disconnect the fuel line at a festo between the pump and engine and try to start again and the fuel would not come out of the line. I would run the pump in test mode with the line disconnected still and the fuel pump would now turn faster and I would get a stream coming out of the disconnected line. I would reconnect and everything would start fine for the rest of the day. I found I can run the pump in test mode with the lines connected but with the manual shutoff between the pump and motor closed. It seems the pump after sitting for a week or two between fying sessions the pump would get ‘sticky”
Take my experience and solution for what it’s worth.

Fuel Pump Type
 

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Do you know if your fuel pump is brushed or brushless.
Sid

Battery Spec??
 

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Fender I found my answer. The manual says 2S Lipo or 3S LIFE. DAh, read the manual.

?? Did you not read my suggestion days ago ??

Battery
 

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Yes I did, Thanks, Merlin says 2S LIPO or 3S LIFE but LIPO is preffered power. I don't know why they prefer 2S LIPO.

Okay cool, just stay below 10v, electronics can get damaged

Sid

my pump is brushless

jack

No worries, it really makes a big difference in consistency on 3s life

Still Puzzled
 

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Every start attempt I get message "Burner On". The manual says next the starter should kick in 3-5 seconds. Most of the time on the first start of the day the starter fails to kick in. After 3-5 attempts it kicks in and normal start Shut it down and immediately start and it never fails with consecutive attempts. I don't know how much time is needed between attempts to get a failed start. I went to fly on Monday and it started on first try which it hasn't done in 2 months.
The start attempt failures occure whether I am using 2S Lipo or 3S LIFE.

Sid when the starter kicks in do you see any RPM indication?

Start Failure
 

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When I hear the starter run, the RPM reading is approx.. 4000 then decays to approx. 2800. I don't think I remember any start failure if the starter kicks in. To my the question is what event occurs to trigger the starter. Is it time? Is it temperature? Or maybe both?