|
dark fuel problem at half tank
Hi guys I have just started flying my new Hanger 9 p-51pts we run a good 3/4 tank thru it at the field and then took it up and trimed it out things were going great but as soon as it gets down to around the half tank it dies and has to be brought in dead stick and the fuel is as dark as coke I come to find out there is another guy that bought one just before me and is having the same problem and hasent fixed his yet either
Just wondering if anyone has heard of this or knows what I can do to fix this problem?? Thanks |
RE: dark fuel problem at half tank
Don't know about the dead stick but the dark mater floating around in there is usually from the engine breaking in and gets into the tank from the pressure line. Dark like coke is a lot more then I have ever seen before but I have never really worked on or with the EV engines so don't know a lot about them. I get some gray mater in my tank from new engines and old engines that are telling me they are in need of looking into.
The little bit of gray I get with a new engine is pretty normal but as dark as you say could be something else?? |
RE: dark fuel problem at half tank
Are you saying that the remaining fuel in the tank turns dark?
|
RE: dark fuel problem at half tank
The fuel line to the engine is connected to a clunk in the tank, right?
|
RE: dark fuel problem at half tank
Joe, that's what he is saying. I would like to ground run the engine and watch the pressure line to see how much crud is getting in there. Some is normal, a lot isn't. Maybe run a few tanks of fuel through it on the ground and I bet it would clear up.
|
RE: dark fuel problem at half tank
yes we pulled the fuel tank out and hose and clunk are fine, we replaced all the fuel lines reseated the carb thing runs great but at 3/4 throtle or more there is alot of grey heading back from the muffler to the tank I checked the baffle plate and the small v grove was at the 9 oclock position so we put it at the 6 oclock mark but that didnt help i wonder if turning the exhaust tip pointing down would help?
this is my first glow plane and dont know much about them!! |
RE: dark fuel problem at half tank
Turning the exhaust isn't the problem but it can be something as simple as a loose baffel in the muffler or a loose muffler too. If you see the gray flowing you know it isn't inside the tank. Just for grins I would remove the baffel and see if it removes your problem. Only takes a minute to test it.
|
RE: dark fuel problem at half tank
yes the grey is definitly flowing to the tank from the vent line
|
RE: dark fuel problem at half tank
I had some vibration in the exhaust system (muffler, muffler extension, baffle, etc) on one of my engines and it produced A LOT of really dark grey sludge. I would check for loose engine/exhaust parts and make sure your engine has enough clearance that it is not touching the fuse anywhere. They vibrate, so make sure you have plenty of room all around the engine.
|
RE: dark fuel problem at half tank
the baffle is pushed in tight and hasent moved at all it has punched out holes but the side of the punch out is still attached and near the outer edge has a small v in it I looked at an alpha baffle and the v was at the very bottom so I moved mine there but still get lots of grey flowing from the muffler back to the tank via the vent line
|
RE: dark fuel problem at half tank
ORIGINAL: gaRCfield I had some vibration in the exhaust system (muffler, muffler extension, baffle, etc) on one of my engines and it produced A LOT of really dark grey sludge. I would check for loose engine/exhaust parts and make sure your engine has enough clearance that it is not touching the fuse anywhere. They vibrate, so make sure you have plenty of room all around the engine. |
RE: dark fuel problem at half tank
What does the side of the plane look like. If you have that much going into the tank, then the side of the plane has to be a mess..Yes????
Is it possible thay you just haven't peaked out the engine? At the point I think you are at, around three or four tanks, the engine is still breaking in. If you are running it rich, there is going to be a lot of oil in the exhaust. Some of this is going to find it way to the tank. Question. What is the peak RPM on the engine and how many RPMs are you running to the rich side from peak?? If you are still running more thatn 500 rpm of peak to the rich side, you are about right for three or four tanks worth. If you are running richer that that, this is probably a part of what you are seeing. You don't say what fuel you are using, or what the engine is. I'm not familiar with the plane you are flying so some engine information and fuel information would be a good start point to figure what is going on. My guess, and it is only a guess, is that the engine is running way to rich and just needs to be tuned. If it is one of the engines with the needle stops, then get a good engine guy at the field to remove them and properally tune the engine. They will be the blue things on both the high speed needle and the idle mix control. Don |
RE: dark fuel problem at half tank
ORIGINAL: Campgems What does the side of the plane look like. If you have that much going into the tank, then the side of the plane has to be a mess..Yes???? Is it possible thay you just haven't peaked out the engine? At the point I think you are at, around three or four tanks, the engine is still breaking in. If you are running it rich, there is going to be a lot of oil in the exhaust. Some of this is going to find it way to the tank. Question. What is the peak RPM on the engine and how many RPMs are you running to the rich side from peak?? If you are still running more thatn 500 rpm of peak to the rich side, you are about right for three or four tanks worth. If you are running richer that that, this is probably a part of what you are seeing. You don't say what fuel you are using, or what the engine is. I'm not familiar with the plane you are flying so some engine information and fuel information would be a good start point to figure what is going on. My guess, and it is only a guess, is that the engine is running way to rich and just needs to be tuned. If it is one of the engines with the needle stops, then get a good engine guy at the field to remove them and properally tune the engine. They will be the blue things on both the high speed needle and the idle mix control. Don |
RE: dark fuel problem at half tank
Get rid of the stops. They will make sure that you can get the enging running. Unfortuantly , they also make sure you can't properly tune it. I've yet to see one run well until the stops are removed and then they are a good engine.
Check with the guys you fly with, and tell them that you want to remove the limiters. If one of them knows what your are talking about, let him help. Removing them are not much of a problem. One setscrew on each if I remember correctly. Once you get them off, the engine tuned properly, then you are in for a very plesant susprise. Good luck and keep us informed on how it goes. Don |
RE: dark fuel problem at half tank
I would still remove the baffel completely then get the engine in correct tune. You won't notice much more noise and they do vibrate and cause crud in the tank quite often.
|
RE: dark fuel problem at half tank
I took the p51 to my lhs today and explaned what is going on he is going to remove the stops and start from scratch to tune this thing also at the request of my instructor he is getting rid of the 3 blade prop and putting a 2 blade on it guess he said he has had to do this with the last 4 p-51's he has sold.said they have been nothing but problems and was just waiting to see if I ran into the same with mine
hope this fixes it I really want to get out this weekend, will let you know how things turn out ps Thanks for all the input |
RE: dark fuel problem at half tank
I had the same problem, campgems has your answer, your running way too rich, take the limiter off and have the carb adjusted, the carbs on the "trainer system" are set real rich, the limiter is there to keep you from leaning it out too much, but won't let you lean out enough, as said you'll notice a difference, the three bladed trainer prop doesn't effect this, but it will fly a whole lot better, especially landing
|
RE: dark fuel problem at half tank
|
RE: dark fuel problem at half tank
Did you verify that the lines are connected correctly? On one of my planes, I have a three line setup and was running my filler line to my carb, rather than the clunk. It did the same. It would run great for a couple minutes, then deadstick. After the switch it ran great.
Good luck either way, Curtis |
RE: dark fuel problem at half tank
yea that was one of the first things we looked at was the lines in the tank
|
RE: dark fuel problem at half tank
I going tomorow to pick it up from the lhs I will post back as to what they did to resolve the problem
|
RE: dark fuel problem at half tank
well i have about 1 gallon run thru it things are going good have had many good take off and landings with it!!
we got rid the 3 blade prop and running a 10x6 flaps all the way up removed the big heavy shaft weight and rebalanced with 1 1/2 ounces running a A3 glow plug aligned the v grove in muffler so its at the bottom and made it a bit bigger and opened up the punchouts and removed the pins on the needles and started from scratch thing works great getting bout 13000rpm 11 min flights with some to spare running 15% omega Im addicted 110% once set up this thing is easy to fly (with instructer of course) |
RE: dark fuel problem at half tank
What was the cause of your problem?
ORIGINAL: 2004play well i have about 1 gallon run thru it things are going good have had many good take off and landings with it!! we got rid the 3 blade prop and running a 10x6 flaps all the way up removed the big heavy shaft weight and rebalanced with 1 1/2 ounces running a A3 glow plug aligned the v grove in muffler so its at the bottom and made it a bit bigger and opened up the punchouts and removed the pins on the needles and started from scratch thing works great getting bout 13000rpm 11 min flights with some to spare running 15% omega Im addicted 110% once set up this thing is easy to fly (with instructer of course) |
RE: dark fuel problem at half tank
the biggest problem was it was way to rich and the needle stops wouldnt let you adjust it plus it seems to really like the hotter plug
|
RE: dark fuel problem at half tank
Glad things are working out. Engine troubles can be frustrating.
|
| All times are GMT -8. The time now is 10:19 PM. |
Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.