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First Engine Start a No Go - Got Brrrrrrrr

Does the engine turn freely by hand?
Would a stuck starter motor cause these two wires to over load?
Yes, especially if the start button is held in for several seconds.
Joe Gores
 
I have taken out the top four spark plugs and turned the propeller by hand. With the plugs out, the prop moves freely.
 
Today, I only held the start for a couple of seconds. But, the wire damage may have occurred a couple of weeks ago, prior to my replacing the starter relay, when I tried to start the engine four or five times. I remember holding the start on for several seconds at that time.
 
Grounded Starter Windings

Chuck,
If you have the power wiring correct......It sounds like the starter windings are grounded or shorted. Find out what the resistance is supposed to be across the starter terminals and ohm them out. If Rotax does not have it readily available, maybe someone with an engine that isn't cowled up can give you a value.

Jersey KARM
 
I'd take a battery with two leads directly to the starter motor and bump it directly to eliminate it as a problem.
 
I'd take a battery with two leads directly to the starter motor and bump it directly to eliminate it as a problem.

I agree, but just 'bump it'! I am NO expert, but what we have here is a case of something definitely overloading for some strange reason. I'd sure like for you to rule out a bad starter, before we keep guessing. Just like on a car, in my opinion, a bad (grounded/shorted) starter could cause all types of havoc on the system- from the starter itself, back toward everything upstream.

Thoughts? And Walt, if you are seeing this PLEASE chime in! I've read many of your prior diagnosis' from afar, and most are right on the money!
 
Ordered two new cables today: Battery Power Cable, P150, and Starter Power Cable, P155.

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Where I have written in 'short' is where the two power cables melted and welded together.

Also did a continuity check on the Battery Ground Cable, P149, and, the Engine Ground Cable, P151. Both checked out good. Also, rechecked the wiring and connections and they appeared to be correct and solid.

If the temperatures get out of the single digits tomorrow, I'll try to 'bump' the starter and see if I get any engine movement.

Really appreciate all the thoughts and ideas. Thanks!
 
Looking for your help/ideas. The temperature got up to 30 degrees today, and, I spent a couple of hours trying to diagnose the starter/short problem.

Here is a picture of the Ground Terminal on the back of the starter:
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Here is a picture of the Power Stud on the side/back of the starter:
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And, here is a picture of the Starter Drawing from Page 46-16:
30mtkqr.jpg


When I put my finger on the Power Stud, I can wiggle it slightly with my finger. The base of the Power Stud seems to be encased in a rubber grommet so that it does not come in contact with the Starter Casing.

When I have been attaching the Starter Power Cable to the Power Stud, the Cable's terminal makes direct contact with the Starter Casing. This, I think, is causing the short.

When I look at the Starter Drawing, there appears to be a piece to isolate the Power Cable's Terminal from the Starter Casing (on the drawing I have circled what I think is a missing part or parts, along with a question mark pointing at the missing part(s)).

Am I barking up the right tree? Can anyone identify the missing parts?
 
Disclaimer-----I am not familiar with Rotax...............

BUT-----

From what I am seeing here, you are missing an insulator standoff from the starter stud, where you have circled the drawing.

Every starter I have seen has some sort of insulator that supports the stud, and also has a nut locking the stud in place. After the cable is attached, a second nut holds the cable down. Washers as needed.

I am pretty sure you have found the cause of the problem.

You may very well have fried your start contactor from this short, BTY.
 
When I look at the Starter Drawing, there appears to be a piece to isolate the Power Cable's Terminal from the Starter Casing (on the drawing I have circled what I think is a missing part or parts, along with a question mark pointing at the missing part(s)).

Am I barking up the right tree? Can anyone identify the missing parts?

Disclaimer-----I am not familiar with Rotax...............

BUT-----

From what I am seeing here, you are missing an insulator standoff from the starter stud, where you have circled the drawing.

Every starter I have seen has some sort of insulator that supports the stud, and also has a nut locking the stud in place. After the cable is attached, a second nut holds the cable down. Washers as needed.

I am pretty sure you have found the cause of the problem.

You may very well have fried your start contactor from this short, BTY.

You (and Mike) have found your problem.

You have been connecting the starter power cable with a direct short to ground.

It looks like someone remove the second nut washer and spacer for some reason. In case it may have happened in your shop, the plastic spacer I have seen most recently are black, and about 3/16 " thick.
 
Appreciate the comments/pictures.

Ordered the Connector Sheath and Nut Washer from Lockwood today.

Should have it all back together by the end of next week. Will let you know what happens with the next turn of the start key.
 
Chuck, you need to inspect every component from the starter back to the battery------both hot side and ground side. A short like you had will melt insulation, fry contractors, and cause crimped on ends to get loosened up on the wires.

Remove each lead (big wires, not the control side little ones) and test if the crimp is still tight, inspect the total length of the wire for damage to the insulation, make sure there is no evidence of arcing at the contact patch where the ground wire is bolted down, ETC.

If you do get the starter to work after getting it all back together, and the starter grinds slowly or sounds like it is struggling, look to the contactor for high resistance from burnt internal points, bad connection on the wire end crimps, or the battery to be weakened. The battery may well show full voltage but not be able to flow the needed amperage any more.
 
A good automotive shop should be able to checkout the motor. There is one here in Phoenix a number of home builders have used.
 
I think any damage to the starter motor is highly unlikely since the power cable had a direct short via the outer housing, to the starter ground cable connected only a few inches away.
Like Mike said, all the cables and associated electrical devices (master relay, start relay, and cables) that carried the high current flow could be damaged,
 
Engine Started!

Yesterday, the 24th, temperature got in the high 30s and it was not snowing or raining. Turned the key and the engine started right up. No phssst of shorting wires, no melting of wires, no shorting. Engine ran rough for about a half minute, then smoothed out.

Took some quick engine readings:
Tachometer at idle: 2860
Oil Pressure: 66psi
Ammeter: 2
Voltmeter: 13.8
Fuel Pressure: 8.0 to 8.1psi
EGT: 109
Cylinder Head Left: 235
Cylinder Head Right: 246

Don't know how to reduce/adjust that fuel pressure down to 2.2 to 5.8psi - any suggestions?

No drips. No leaks. Ran for about three minutes before shutting down. Checked the oil level and it was at the minimum line. The coolant in the overflow bottle just barely covered the bottom - not up to the minimum line.

Really appreciate all the help, comments and photos. Thank You!

And, yes, I just sent in my 2014 dues to VansAirForce. This site is worth every penny.
 
CHT's over 230 degrees in only 3 minutes? With OAT near 30 degrees and assuming at far below full power?
Something doesn't look normal regarding your cooling system.
 
Make sure you fill the coolant overflow resorvoir to at least the halfway mark. Only filling the main coolant holding tank may result in not enough fluid by the time hoses, pump, and radiator are filled during operation.

EGT 109? Do you have EGT and CHT backward in your post? EGT should be fairly high. Even above 230 range. 109 is a believable CHT number on an uncowled cold day run for 3 minutes.
 
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The CHT's at those OAT's and idle rpm should be closer to 165-180. Check the coolant level in the fill tank. If you have a thermostat make sure it isn't in backwards or mis-connected. If you have a Dynon or some other EMS go into menu and setup, then sensors then down to fuel pressure parameters. They should be between 2.2 to 7.2 psi. Warm up is better between 2000-2400 rpm and you should be able to throttle back down to 1700-1800 rpm after the engine oil temp reaches 120F.
EGT 109F?? Is that supposed to be 1009F? When you start up again it would be a good idea to sync the carbs.
 
Before I'd start too much trouble shooting I'd make sure the coolant system is free of air, fill the overflow bottle to above the minimum and do another run to check parameters again. My first run went smoothly, but there was some "gee wow" factor that prevented me from getting accurate readings until the second or third run.
 
Did you start with throttle idle and starting carb ("choke") pulled full open? Then after a couple of minutes you can ease in the choke and add a little throttle. Thats the normal method for cold weather. Keeping the rpm below 2500 until the oil has reached 120 defF. But those numbers do seem strange. Always look at the egt, cht, and oil before start to see that they look reasonable (i.e. At ambient). What was fuel pressure prior to start (which would have been from the electric pump only.) If you didn't do that at the time, you can still download all that info to a USB stick from the Dynon and check it on your PC.
 
Congratulations!!

Engine Started!

Yesterday, the 24th, temperature got in the high 30s and it was not snowing or raining. Turned the key and the engine started right up. No phssst of shorting wires, no melting of wires, no shorting.

Really appreciate all the help, comments and photos. Thank You!

And, yes, I just sent in my 2014 dues to VansAirForce. This site is worth every penny.

Congrats on the first start, bet you feel like this is the best Christmas of all.

Glad we could help you get the beast going:D
 
Huge smile on my face when the engine started.

Today I will go out and look more closely at the engine. Fill the oil to the half way mark and fill the coolant to the half way mark on the overflow bottle.

Next engine start I may be more calm, cool and collected and get better engine data.
 
..........Took some quick engine readings:
Tachometer at idle: 2860
Oil Pressure: 66psi
Ammeter: 2
Voltmeter: 13.8
Fuel Pressure: 8.0 to 8.1psi
EGT: 109
Cylinder Head Left: 235
Cylinder Head Right: 246

Don't know how to reduce/adjust that fuel pressure down to 2.2 to 5.8psi - any suggestions?

No drips. No leaks. Ran for about three minutes before shutting down. Checked the oil level and it was at the minimum line. The coolant in the overflow bottle just barely covered the bottom - not up to the minimum line.

.......................

Chuck - Suggestions - Prioritize and sort out anomalies in order.

Number one concern - high CHT/low coolant level - get more coolant into system and expel air BEFORE any more extended engine runs. Try filling reservoirs and cranking engine with ignitions off to expel air.

Number two concern - High idle RPM, above 2500 limit - check idle adjustment screws (factory settings should be fine), and throttle cable linkages at the carbs. Sounds like one or both is improperly set.

Number three concern - odd temperature readings. Make another engine run after resolving one and two above, double check readings.

Don't sweat the high fuel pressure readings for now. You can diagnose that issue after the higher priority issues have been resolved.
 
Chuck - -

Coolant level in the over-flow bottle is NOT critical initially. The TANK IS CRITICAL. Take the cap off and be sure you have enough in that tank. Right to the top ! After that is satisfied, then put an inch in the over-flow. As others have said, the coolant temp is your first concern. If the fuel pressure is that high, you would likely not have a good running engine. Satisfy the coolant needs first, then de-bug from there.
 
To clarify JB's post, check the coolant level at the expansion tank (the black tank on the top of the engine) not the overflow bottle. If your overflow bottle had nearly nothing in it after your first run, it is an indicator that the system wasn't full and it pulled coolant out of the overflow bottle. It sometimes is helpful to push the tail all the way down with the cap off to purge some air and then top it off the rest of the way.

The reason for the concern about the idle speed is that you are supposed to stay below 2500 RPM until oil temp hits 122 F. If this wasn't the case on your first start, it should not be started again until this is rectified.
 
Forgot to mention. If you have a digital EMS many have sensor setups that may have more than one choice for sensor type. For instance Dynon may have sensor 1 or 2. Sometimes they have up to 10 choices for a sensor. Make sure you have the EGT sensor type on the correct one if you have this in your setup.
 
Yesterday, 26th, did a few things:

Engine oil. The oil level was low. So, I put in about another 1/4 litre. I have now got 3 1/2 litres in the engine (per the scale on the side of the bottle). Alternated burping the oil and letting it rest several times. Now, the oil level is between 1/4 and 1/2 up on the flat part of the oil dip stick in the tank - depending on whether or not I have just burped the oil.

Coolant. The coolant in the black tank on the top of the engine was down about 1 1/2 inches from the top. Poured coolant into the black tank until it was at the top. Also, poured coolant in the overflow bottle on the firewall to about half way between the min and max marks. I'll push the tail down today to see if I can purge any more air out of the system.

Air Flow. Pulled off the orange connecting hose between the lower cowling nose and the air shroud on the top of the engine. Put an eyeball to both the hose and the shroud and could find nothing to block the air flow. Noticed that the air shroud on the rectifier, where I had put red RTV on the top four corners, had blown out the RTV on the two front corners.

Skyview EMS Setup. Entered the EMS setup and saw you have engine wizard choices: Lycoming, Continental, Rotax S/ULS, and Other. It is currently set up on Other. It may be on Other because the Skyview EMS display shows a green dot, or red dot, for the spar pins. The engine parameters seem to be correct, i.e. 5800 max rpm, etc.

Skyview Data Download. Tried to do a download of the engine performance data onto the Dynon thumb drive. Somehow, I screwed it up because I had nothing on the thumb drive when I got home.

Sensors. Thought that I would check the wiring and sensors today to make sure I attached the wiring to the correct sensors.

Yesterday, there was ice on the hangar floor where the roof leaks - you could say I was 'skating around'. This afternoon the temps are supposed to get in the high 30s.
 
Second engine start today, 12-30-13.

Here you see where I killed the engine by letting the choke out to fast on a 37 degree F day:

i5ruvk.png


And, the cylinder head temperatures:

2rhqq2d.png


Today I took the cap off the black coolant tank on top of the engine. Then, pushed the tail of the plane all the way to the ground and moved it left and right. Put the nose back down. Pinched off the line between the black coolant tank and the overflow tank. Then applied my lips to the top of the black coolant tank and blew as hard as I could. Neither maneuver seemed to have much effect.

After the engine run I moved the -12 back into the hangar and I noticed coolant dripping on the floor under the coolant radiator. Coolant had blown back on the bottom of the fuselage. Took off the lower cowling and found that both of the black hoses attached to the radiator (upper and lower) were not clamped tightly and were leaking. Gave both clamps a couple of full turns on the screw and brought them up tight.

Tomorrow is supposed to be another balmy day, and, will try another engine start.

Contrary to the first engine start, I was much more calm, cool and collected today.
 
Chuck, be of good cheer, you are making progress in your troubleshooting. Good job keeping the RPM under 2500. You might want to leave the cowling off for your next run so you can easily observe any other leaks. Keep the test runs short until you solve the cooling problem, as you did this time.
 
Engine is running. Thought I would share some of the problems and solutions I have run into.

High Cylinder Head Temperatures. Problem: The cylinder head temperatures, while running the engine, would steadily climb until they hit the yellow zone, and, I would then shut down the engine. Solutions: 1) take the cap off the expansion tank and lower the tail of the aircraft to the ground, 2) pinch off the line between the expansion tank and the overflow tank, pucker up and blow into the expansion tank, and 3) drain all the coolant out and refill making sure there is coolant in the overflow tank. For me, solutions one and two had no effect. While performing solution three, I ran into this:

2ynq6q1.jpg


Yup, I had left the lower and upper plugs in the radiator - so, no coolant was circulating through the radiator. My only excuse is that those are black plugs in a black radiator, and, I was putting on black hoses. On January 7th I ran the engine again and the cylinder head temperatures were right in the middle of the green.

High Fuel Pressure. Fuel pressure had been running 7.7 and 7.8 psi. That is in the red zone. While checking yesterday for coolant leaks, I noticed that the threads on the elbow coming out of the gascolator appeared to be wet. Put my finger on the wet and sniffed - sure enough, it was 100LL. Took the elbow off and applied a good amount of pipe dope to the threads and reinstalled the elbow. Here is a picture of the elbow:

168v0c6.jpg


Turned on Skyview and the fuel pump, and, the fuel pressure was right in the middle of the green zone. The threads on the elbow out of the gascolator were dry.

Hope this will prove helpful to someone else when they do a 'search' on this forum. I know the 'search' function on this forum has been very helpful to me during the build.
 
High Fuel Pressure. Fuel pressure had been running 7.7 and 7.8 psi. That is in the red zone. While checking yesterday for coolant leaks, I noticed that the threads on the elbow coming out of the gascolator appeared to be wet. Put my finger on the wet and sniffed - sure enough, it was 100LL. Took the elbow off and applied a good amount of pipe dope to the threads and reinstalled the elbow. Here is a picture of the elbow:

168v0c6.jpg


Turned on Skyview and the fuel pump, and, the fuel pressure was right in the middle of the green zone. The threads on the elbow out of the gascolator were dry.

Hope this will prove helpful to someone else when they do a 'search' on this forum. I know the 'search' function on this forum has been very helpful to me during the build.

Good job Chuck.

One comment... Thread sealant is not used on flared fitting connections (like the hose connection to the gascolator), only on pipe thread connections where the seal happens within the threads (where the elbow fitting is threaded into the gascolator).
 
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