Notices
Merlin Turbine Clinic Support for Merlin Turbines is provided in this forum

Merlin 90 fire ball

Old 08-03-2014, 02:27 PM
  #1  
mikes68charger
Thread Starter
My Feedback: (34)
 
Join Date: Oct 2010
Location: , OH
Posts: 1,954
Received 7 Likes on 5 Posts
Default Merlin 90 fire ball

Hey guys I need some help. A good friend of mine has me working on his Merlin 90 turbine as he guess me being a mechanic in the Army im supposed to know how to fix stuff.

All I got on the history of this motor is he got it new, put it a Skymaster Viper. After caching his viper on fire he sent it back in to dreamworks. They said nothing was wrong. Then he repainted it the tried again once again fire.

So he tells me it just came back from Jasper and once again fire and he swear that he has not changed and setting

So I put it on my little test stand and try her out as I know as a mechanic you most of the time get part of the story

So you can see from my video that this motor is a fire ball.

I double checked the manual and all is connected correct

So im looking for some advice

Thanks Mike 832 857 6931 cell
https://www.youtube.com/watch?v=w84m...e_gdata_player
Old 08-04-2014, 01:43 AM
  #2  
mauryr
 
Join Date: Dec 2010
Location: , ITALY
Posts: 510
Likes: 0
Received 3 Likes on 3 Posts
Default

Dial down your preheat pump pw by 3 or 4 points to reduce/remove flaming on the first part of the start.
If you get flames during fuel ramp, also decrease by one step the "fuel ramp start" from like auto+3 to auto+2 or from auto+2 to auto+1

The above advice applies if and only if:
1) you did not flood the engine during fueling, transportation or whetever.
2) the fuel lights up STRAIGHT AWAY as soon as the soloenoid starts ticking (assuming the fuel line is properly primed)

If your test doesn't meet these 2 points, fix these before changing anything.

Also, NEVER stay on the rotation plane of your engine, especially whenever the engine goes above idle! Being a mechanic in the army you should know this!
Old 08-04-2014, 06:54 AM
  #3  
basimpsn
My Feedback: (5)
 
Join Date: Dec 2001
Location: Mia, FL
Posts: 2,579
Received 4 Likes on 4 Posts
Default

First swap the fuel lines...
Old 08-04-2014, 08:02 AM
  #4  
mauryr
 
Join Date: Dec 2010
Location: , ITALY
Posts: 510
Likes: 0
Received 3 Likes on 3 Posts
Default

Originally Posted by basimpsn View Post
First swap the fuel lines...
The engine starts and runs, I doubt it would if the fuel lines were swapped.
Not to mention the merlins have the valves in the engine and only one fuel line!
Old 08-04-2014, 12:16 PM
  #5  
mikes68charger
Thread Starter
My Feedback: (34)
 
Join Date: Oct 2010
Location: , OH
Posts: 1,954
Received 7 Likes on 5 Posts
Default

Originally Posted by mauryr View Post
The engine starts and runs, I doubt it would if the fuel lines were swapped.
Not to mention the merlins have the valves in the engine and only one fuel line!
No this one dose have 2 valves and 2 lines but the start kero line is smaller
Old 08-04-2014, 04:24 PM
  #6  
mikes68charger
Thread Starter
My Feedback: (34)
 
Join Date: Oct 2010
Location: , OH
Posts: 1,954
Received 7 Likes on 5 Posts
Default

Well I turned the pump start down to 30 it took a little more time to start and a little less flam but still way to much to put in a plane. And still just as much flam in the run stage.

So if I were to buy this motor who would I have to send it to for repair?
Old 10-24-2014, 06:09 AM
  #7  
Cliffhanger
Member
 
Cliffhanger's Avatar
 
Join Date: Oct 2005
Location: Gangelt, GERMANY
Posts: 72
Likes: 0
Received 0 Likes on 0 Posts
Default

The best option is to send it back to Jets-Munt for a cleanup/tuneup
It is not the cheapest option but trust me, Gaspar will fix the issue.
What runtime does the turbine have?
Old 10-25-2014, 06:50 AM
  #8  
joeflyer
My Feedback: (47)
 
Join Date: Dec 2001
Location: Plymouth, MI
Posts: 2,925
Likes: 0
Received 13 Likes on 11 Posts
Default

My M90 starts fine with no flames. My only complaint is that it takes a full minute to go through the start sequence.

You could no doubt reduce flames during the start sequence by tweeking some of the parameters, but since it appears that you are also getting some flames during Run mode that's probably not going to fix it.

You could have a clogged injector or two. In your video the flame seems to be biased to one side. Another possibility is that you are putting too much voltage to the fuel pump. This could be due to an ECU problem, using the wrong battery or the wrong pump. What battery are you using?

Your best bet is to email Gaspar and let him look at your video. It would help to show the complete start sequence and have the HDT connected and in view so that he can tell what phase of the start sequence you are in. He will probably want you to send him the engine, pump and ECU.

His contact information is on the Jets Munt web site. http://www.jets-munt.com/
Old 08-15-2015, 09:03 AM
  #9  
cmp3cantrj
 
Join Date: Jan 2011
Location: NewarkNottinghamshire, UNITED KINGDOM
Posts: 134
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by joeflyer View Post
My M90 starts fine with no flames. My only complaint is that it takes a full minute to go through the start sequence.

You could no doubt reduce flames during the start sequence by tweeking some of the parameters, but since it appears that you are also getting some flames during Run mode that's probably not going to fix it.

You could have a clogged injector or two. In your video the flame seems to be biased to one side. Another possibility is that you are putting too much voltage to the fuel pump. This could be due to an ECU problem, using the wrong battery or the wrong pump. What battery are you using?

Your best bet is to email Gaspar and let him look at your video. It would help to show the complete start sequence and have the HDT connected and in view so that he can tell what phase of the start sequence you are in. He will probably want you to send him the engine, pump and ECU.

His contact information is on the Jets Munt web site. http://www.jets-munt.com/
I know this thread is old - but in case anyone has a similar problem I would note that one possibility is that the kerostart burner valve is not closing fully this will result in some liquid fuel entering the engine in a place where it won't vapourise (burner heat will be off by this point) until it is outside the combustion chamber - eventually it will vapourise and burn either through the ngv/turbine wheel or in the tailpipe - hence the flames.
Old 08-31-2015, 06:08 PM
  #10  
RCISFUN
My Feedback: (44)
 
RCISFUN's Avatar
 
Join Date: Apr 2002
Location: Erie, PA
Posts: 6,788
Received 21 Likes on 18 Posts
Default

Originally Posted by cmp3cantrj View Post
I know this thread is old - but in case anyone has a similar problem I would note that one possibility is that the kerostart burner valve is not closing fully this will result in some liquid fuel entering the engine in a place where it won't vapourise (burner heat will be off by this point) until it is outside the combustion chamber - eventually it will vapourise and burn either through the ngv/turbine wheel or in the tailpipe - hence the flames.
If this were the case then a simple check would use a set of forceps to clap the burner line after the start sequence is finished to see if the excess flames diminish, if so this would prove that the the valve is indeed leaking.
Old 09-01-2015, 05:22 AM
  #11  
cmp3cantrj
 
Join Date: Jan 2011
Location: NewarkNottinghamshire, UNITED KINGDOM
Posts: 134
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by RCISFUN View Post
If this were the case then a simple check would use a set of forceps to clap the burner line after the start sequence is finished to see if the excess flames diminish, if so this would prove that the the valve is indeed leaking.
Good idea - however, given that the tubing here is usually the hard type it might be better to insert a Festo manual valve into the line - and close it after the start.
Old 10-16-2015, 06:19 PM
  #12  
gooseF22
 
gooseF22's Avatar
 
Join Date: Aug 2006
Location: Fort Wayne, IN
Posts: 2,602
Received 2 Likes on 2 Posts
Default

I have seen them act that way when a piece of trash gets lodged in the pump or valve.. preventing closing all the way..

if the valves are outside the motor, then swap and replumb. I see a hotspot forming around the igniter/injector.. that tells me something is amiss in the kerostarter igniter area..
Old 10-16-2015, 06:21 PM
  #13  
gooseF22
 
gooseF22's Avatar
 
Join Date: Aug 2006
Location: Fort Wayne, IN
Posts: 2,602
Received 2 Likes on 2 Posts
Default

also teflon line doesn't seal well after being pulled out of a festo, so might need to cut it again.. it must be very square and not crushed.. cut slowly with a razor

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2022 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.