Need help

[ptstan]

need help!! I have pt22 robin engine, when i start it up i pull the choke down and it starts up but when i disengage the choke it stalls out anyone know what the problem could be? also the engine really runs hot for some reason i did change the fuel filter...could that be the cause of my problem? any help would be appreciated.

 

[MossRoad]

Welcome to TBN!

 

[concrete]

Check for a clog at the elbow in the bottom of the tank. You may not see it a first glance but it could be clear plastic particles.

 

[ptstan]

thanks for your help i really appreciate it..my son is sitting here helping me type this out he knows all of this computer stuff i'd be lost without him....if thats not the problem though could it be something else?

 

[woodlandfarms]

Its a good place to start (the elbow). Beyond that it gets more and more complicated. PT has a notoriety for clogs at the tank. Air Filter is clean, right?

 

[concrete]

PTSTAN, I am so good at this that I type with one finger , and I can even spell better than I can type. The usual questions, how old is the engine, did this just start ect. More clues please.

 

[BobRip]

It does sound like a fuel starvation issue. I believe that running hot is also a sign of running lean. Go with the elbow first, check the venting of the cap (this is probably not the cause) and then change the filter again (it's cheap and easy right). Next would be the fuel pump.

Do you see bubbles in the fuel line. This is a sign of a clogged line, elbow, or filter if it is after the filter. Can you keep it running by opening the choke only part way? This will let it run and you can watch for bubbles.

I had the elbow clog, like several others around here.

 

[coolconnection]

I have bubbles in my fuel line after I mow for a while. When I shut it off you can see it bubble for a little bit then it stops. It runs just fine though. Do you think my gas is boiling? That sounds serious to me.

 

[carpenter383]

If it needs choked to run it's definately a lean condition. A vacuum leak could cause this as well as clogged fuel lines as others have said. You could blow compressed air through the lines to try and get the clog out. Or check for a vacuum leak by spraying carb cleaner around the intake/carb and intake/head gaskets.....Did you put the fuel filter on in the correct direction of flow?

 

[Marks481]

also the engine really runs hot for some reason i did change the fuel filter...could that be the cause of my problem?

Did the choke problem start after you replaced the filter or before?

I noticed on my PT422 that the location of the filter and size of gas line meant that the line and filter would not refill by the force of gravity, and a large bubble stayed in the fuel filter after it was replaced. This meant the engine was not self priming.

The immediate fix was massaging the tygon gas tubing and tipping the fuel filter until I got all of the bubble out.

The long term fix was to replace the tygon tubing with real black rubber 1/4" fuel line, and relocate the filter until it is directly below the fuel tank and vertical so it refills by itself, and get rid of the 90 degree angle on the outlet of the fuel tank.

 

[Marks481]

Do you think my gas is boiling? That sounds serious to me.

Probably. But not as serious as it sounds unless it prevents your engine from running (which would be vapor lock, when the gas flashing to vapor prevents your fuel pump from pumping the gas).

I had a ratty porsche (ie VW) 914 when I was a kid, and in the summer, the close proximity of the fuel pump to the exhaust pipe meant the fuel would boil in the pump, and it would stop pumping. The engine would stop until it cooled down. I read about a 914 "drive-in" in California where about a hundred 914s died on the side of the road due to vapor-lock.... I wonder if there are even 100 914s in existence today?

The fix was of course to move the electric fuel pump AWAY from the exhaust manifold, and put an insulating sheath around the gas lines.

Regardless, get rid of the stupid tygon hose and replace it with good black rubber gas lines. The following types of insulation around your gas line might also be a good idea:

Design Engineering DEI 010418 - DEI Heat Sheaths – SummitRacing.com
Design Engineering DEI 010421 - DEI Cool Tube Extremes – SummitRacing.com

 

[J_J]

I gave away a 914 last year. .It had been sitting about 5 years. Have to many vehicles.

 

[Gravy]

I'm pretty sure that most 914's have long ago rusted away. Too bad - they were a lot of fun.

 

[woodlandfarms]

Ugghh I wish i had known you had a project 914. I just let the charger go and am looking for a fun project... Slap a subaru engine in that bad boy and you would have a great little rocket...

Oh Well....