New PT-422 Stalls

[MCGN]

I am both a new PT-422 owner and new poster on this forum. Sorry in advance if I am asking a simple question, but I am struggling to find a solution to this problem. My PT has less than 30 hours and I have used it primarily for moving dirt/stone/etc. I began experiencing a problem 5-6 hours ago where the PT would lose all power and stall. I changed the following (oil, oil filter, plugs, fuel filter, air filter) and the PT ran great for a few hours then the same problem happened. I randomly get 30 minutes of work in (when it runs great) and then it quits. My belief is the engine is not getting fuel consistently, but I am at a loss to figure out what to do. I experience the same problem with the gas cap loosened.

I have talked to PT (they recommended changing the fuel filter and plugs) but beyond that, they said I should take the tractor to a Robins dealer. Unfortunately, I am not very experienced with this type of work, but was able to work through the simple changes above.

Any suggestions would be appreciated.

Thanks

 

[Marks481]

Clogged carburator jet? (easy to clean/replace)
Debris in the carburator float bowl?
Debris in the gas tank?
Water-logged carburator float?

What are you doing when it stalls? Is it when it first starts or after you have been using it for awhile? Some people have had problems with the fuel pump getting vapor-locked due to the close proximity of the fuel line and the fuel pump to the muffler causing the fuel in the line to boil. First way to fix it is tto replace the clear plastic fuel line with some quality solid blackj rubber line, and either shield or move the fuel pump.

Did you talk to Terry at PT or someone else? Jack Robin, where are you?

 

[MCGN]

Thank you for the suggestions. I spoke with Terry. He mentioned the possibility about this being a fuel shut off problem (I may not have the terminology correct), but that was when I got pointed to Robin Engines.

 

[woodlandfarms]

I second Vapor Lock.... If it runs fine on startup but falls apart after a half our or so...

 

[SnowRidge]

Welcome to the forum.

We like to know where everyone is located mainly because we are nosey , but also because location can sometimes help in diagnosing problems or suggestion solutions (altitiude, weather, etc.), so it's a good idea to fill out the location information in your profile.

You have already taken the first step I was going to suggest by running with the gas cap loose, so that eliminates fuel starvation due to a clogged tank vent.

Since you ran for some 25 hours without any trouble, was there anything obviously different about your operating conditions when the problem first showed up? Was it hotter, or did you move the machine to a higher altitude, etc?

Exactly how does it die? Does it miss, then stop? Will it run at all? Will it only idle, but not pull a load? All info helps.

 

[TheBigHeadKid]

Welcome,

Also check the 90 degree plastic fitting on the bottom of the gas tank. Several people including me had problems with glue (from the tank) breaking apart and getting stuck in the elbow, again restricting fuel.

 

[MCGN]

Thank you. I will try some of those suggestions today. There was no change in operating conditions when the problem first started - although I did have a very dirty air filter from moving dirt (60 yards).

The problem is not load related. It can happen randomly, but also it may work for a while perfectly. Once the problem starts and the engine stalls (not instant shut off - rather like it is choked for gas), it will start again (sometime right away), but then typically stalls immediately.

When this happens, I try to move around the fuel line and filter (without buring my arm) and this helps sometimes.

 

[SnowRidge]

Not having a Robin myself, I can only offer general suggestions. I understand that they are susceptible to vapor lock. I wonder if you have some crud trapped under the engine shroud that is causing it to run slightly hotter than when brand new, thus triggering the vapor lock issue.

You might try blowing the cooling air passages out with compressed air, and see if that helps. Some of us do that after every use.

 

[SpringHollow]

Unfortunately, some people have had crud left over from manufacturing still in their gas tank which ended up restricting fuel flow in a manner similar to what you are seeing. You might want to drain the tank and inspect it.

Ken

 

[MossRoad]

Unfortunately, some people have had crud left over from manufacturing still in their gas tank which ended up restricting fuel flow in a manner similar to what you are seeing. You might want to drain the tank and inspect it.

Ken

I'd agree with you. There have been numerous reports of crud in the fuel tank that settles in where the fuel leaves the tank.

The first thing I'd do, and it costs less than five bucks, is get a clear fuel filter from an auto parts store and put it into the fuel line near the gas tank. That way you can see if fuel is even getting to the filter from the tank. You can also check it at each refueling to visually see if crud is getting into it from the tank. Also, get a large funnel with a screen in the neck and use this when you refuel. It is amazing how many times I have found a blade of grass or speck of leaf in the funnel after fueling.