Fuel pump help

[Tribal Croc]

Help me please

The past 2 mornings I battle to start my 582 I keep flooding it and the end up using the pull start because it sounds like the battery is getting flat
But in the afternoons it starts no problem

Here is my staring sequence
During pre-flight I press the accelerator once to see if the cable moves freely
Then turn the prop 2 times
Using the mechanical fuel pump for 3 sec to fill carburettors
Choke on
Maggs on
Then turn
Usually this works every time

This morning I notice at the back of the “fuel pump” when I try to pull start there is petrol coming out of a small hole and this is squirted onto the battery, this is the first time I have seen this

Is this normal or should I be worried

Needless to say when I got it started I was worried about my findings and did not fly

[falconp1]

Well spotted Tribal.

1. Could be that the engine was badly flooded and some fuel ran into the pulse pipe, but that is a long shot.

2. If it is petrol squirting out of the breather hole continuously then that is a sign that the pump diaframe is perished and needs to be replaced.

[Alkemac]

Tribal Croc,

Mt first and biggest concern is the potential fire hazard if this is squirting out on the battery!

Secondly, it sounds very much like my issue.. Somehow, the fuel being pumped is flooding the carbs - try running it for a shortwhile, and switch off before starting.

[Tribal Croc]

Thanks for the reply’s

I went back to the hanger and it started up no problem

I think the problem is I am flooding it with the mechanical pump

So what I noticed is just staring without “priming the carbs” & with choke on – no problem

The one thing I forgot to mention is that when I stop my engine at the end of the last flight (like last night) I use the choke to kill the engine then switch the maggs off could this have an efect with me flooding the carbs in the mornings

Can you guys confirm that on your fuel pump there is the same little hole as per my picture and if so I am tending to think that falcomp1 could be write in saying that when the engine is so flooded, fuel will be squirted out of that little hole

Also when the engine eventually started this morning no fuel was squirted out so I think that the pump diagram is still ok

The only other real concern is like Alkemac said this it is a BIG fire hazard

[Duck Rogers]

That little hole is supposed to be there and its function, according to Rotax, is to purge the pump of fuel that could find its way into the pulse line that "feeds" the pump with vacuum from the engine case. If the pump is installed incorrectly then fuel from the crankcase can enter the pulse line and find its way to the pump. To prevent this, make sure the pump is installed higher than the pulse port. The other thing that can happen is if you "over-prime" the carbs, then the fuel will back-up into the line and find its way into the pump. It has nowhere else to go but out of the weep hole. Seems this was the case with yours.
Also ensure that the pulse line is no longer than 300mm from crankcase to fuel pump and that the correct type of fuel hose is used. Do not use crappy "el cheapo" fuel line here. Make sure it is relatively stiff with a decent wall thickness otherwise the vacuum from the crankcase will/can suck it closed with the result being fuel starvation and the pilot having to execute an unscheduled landing.
BTW, either move the fuel pump as explained or move that battery

[nickjaxe]

My thought was if you use the choke to flood/kill the motor...you putting a lot of unused fuel into the casing to just lay at the bottom....my guess is that that is entering the lower part of the pump housing via the pulse line and venting via the drain hole, and also flooding your motor on next start-up,

I would stop using the choke to kill the motor....it will be awash internally with fuel doing that.

Nick.

[Tribal Croc]

Thanks Duck

My fuel hoses where replaced when I bought the plane with the ones you are referring to and has done over 100h now

All the fittings and pipe lengths are 100%

I Didn’t use the choke/stop method last night and had the same problems this morning

Flooding that eventually leads to petrol being squirted out but as soon as the engine starts no squirting

I think I will replace the diaframe in the pump this week

[Technocrat]

Please let us know what the outcome is.

[Tribal Croc]

Will do going to do it over the weekend

[Morph]

This might sound really wierd but...

It is winter, and your battery could be on it's way out. If the motor does not spin fast enough you could struggle for hours, eventually creating other issues like flooding. Yet a simple pull start works.

I even had my solenoid for my starter motor arc across the contact points resulting in a bad connection. The starter sounded perfect, but the damn engine would not start eventually flooding. I took the starter to an autoelectrician for a service and he told me it was perfect. Eventually I shorted across the solenoid and the plane started on first swing. Opened the solenoid up, cleaned the contact, and viola, no more starting issues.

Check the battery first. Use another battery, or jumper from your car and see if this helps.

[Duck Rogers]

..........and if all else fails, reposition the fuel pump with as short a pulse line as possible (as short as you can go and less than 300mm)
You can thank me later...

[Tribal Croc]

Decided to rather buy a new fuel pump than to battle with diaframes

I still need to open the old one to inspect the diaframes, but she started up first time this morning and no flooding

Thanks for all the help

[Technocrat]

Decided to rather buy a new fuel pump than to battle with diaframes

I still need to open the old one to inspect the diaframes, but she started up first time this morning and no flooding

Thanks for all the help

Where did you buy the new pump, and what did it cost?

[Reuben zu-ccm]

Tribal Croc / Technocrat

I bought my fuel pump from CPS America 800-Airwolf Rotax Parts online R 480.00 three week for delivery in SA
Reuben ZU-CCM
0829094722

[Tribal Croc]

Tribal Croc / Technocrat

I bought my fuel pump from CPS America 800-Airwolf Rotax Parts online R 480.00 three week for delivery in SA
Reuben ZU-CCM
0829094722

paid R1444 @comet