Clean up that carb

[SwampmanLA]

I got hold of some bad gas a couple of weeks ago (water) and my 422 with the Robin was not liking it. Well I just want to say that that carb is so easy to clean it was almost fun. And after putting it back together and mowing a little, the Robin has never run better. So for all the Robin haters out there maybe you need to clean your carb.

From the Swamp

 

[coolconnection]

I know nothing about this engine. I have the 425 so let us know what you did and how you did it.

 

[BobRip]

I know nothing about this engine. I have the 425 so let us know what you did and how you did it.

Did you replace any parts? Pictures? How much carb cleaner? What was particularly dirty? What did you have to take apart? Did you pull the carb off the engine?

 

[BobRip]

I pulled my carb today and cleaned it. I damaged the gasket between the engine and carb and had to order another. I will be down for two days!! OMG!

It was easy to remove, disassemble and clean. I hope it runs better.

 

[Phils]

I had a problem 'in the field' some years ago on my 422 and disassembled and cleaned the carb there. I didn't pull it off of the manifold, I just removed the top so I could access the float and bowl. It was easy EXCEPT for the fear of dropping a screw or needle valve or spring in the weeds. I worked VERY carefully and whatever the problem was, cleaning fixed it.

Too long to remember but it was either a stuck float, crud in the needle valve, or crud in the shutoff solanoid, or something else that cleaning the carb fixed.

That was early on when I was still pumping that white goo from the tank through the system.

Phil

 

[MuncyBob]

Did mine earlier this summer. Easy even for a carb novice like me. My problem was the engine surging...none of the easy fixes worked. I was afraid of ruining a gasket but just took my time and all went well. Runs like new now! Took about an hour for me and all I used was 1/4 can of carb cleaner. Replaced fuel filter was I was at it too.

 

[BobRip]

After the rebuilt yesterday, I started it right up on first try. Before, I had to crank with choke off first, or it would flood. Then I would crank with choke on to start.
So it starts better hot and cold.
I found a screw with a spring on it on the left front of the carb. Prior to rebuild, I found it fully turned in. I left it partially open and noticed gas coming out near the bottom of the engine when the tank shutoff was opened. Evidently it drains the carb through a tube leading down. I could not start the engine initially until it was closed. I could not find this in the manual. But now you know.

 

[stray]

Did mine earlier this summer. Easy even for a carb novice like me. My problem was the engine surging...none of the easy fixes worked. I was afraid of ruining a gasket but just took my time and all went well. Runs like new now! Took about an hour for me and all I used was 1/4 can of carb cleaner. Replaced fuel filter was I was at it too.

I had this problem. Seems like I took out one or two screws down side the carbrator, blew out with an air nozzle and that cured the engine surging. the engine surging WAS quite annoying.

 

[J_J]

After the rebuilt yesterday, I started it right up on first try. Before, I had to crank with choke off first, or it would flood. Then I would crank with choke on to start.
So it starts better hot and cold.
I found a screw with a spring on it on the left front of the carb. Prior to rebuild, I found it fully turned in. I left it partially open and noticed gas coming out near the bottom of the engine when the tank shutoff was opened. Evidently it drains the carb through a tube leading down. I could not start the engine initially until it was closed. I could not find this in the manual. But now you know.

That tube and screw is used to drain the carb, like when you get water in the bowl. I wish Kohler had that set up. I have to loosen the nut on the bottom of the bowl to drain. I think Honda had the bleed screw also.

 

[BobRip]

That tube and screw is used to drain the carb, like when you get water in the bowl. I wish Kohler had that set up. I have to loosen the nut on the bottom of the bowl to drain. I think Honda had the bleed screw also.

Thanks J_J, that was my guess, but it sure is nice to have confirmation.

 

[SwampmanLA]

Sorry for not getting back sooner but I still have to work and have been away. I started by pulling the top off of the carb, checking needle value, float, jet, and emulsion tube. Blew through all with air and carb cleaner. It was going so good I removed the two large bolts holding the carb base and cleaned it real good too. Really no need to do this because doing so did not allow access to other little holes to blow through. Put it all back together and had no extra parts. I think that is a first!

 

[BobRip]

I have been running the PT422 for about a week with the clean carburator. It starts every time cold the first time and almost as good hot. Big improvement.

 

[SwampmanLA]

Glad to hear it. I have been happy with my clean carb as well. I rarely go more than a week between starts but I wonder if Stay-bil gas treatment is needed to keep it clean. Cause it looks like a squeaky clean carb is needed for the Robin to perform.

 

[BobRip]

Glad to hear it. I have been happy with my clean carb as well. I rarely go more than a week between starts but I wonder if Stay-bil gas treatment is needed to keep it clean. Cause it looks like a squeaky clean carb is needed for the Robin to perform.

I put Stay-bil in all of my gas cans when I fill them at the gas station. I keep a lot around for the generator, so it may sit for months.

 

[BobRip]

I should have kept quiet. I am having the same problem of flooding if I start the engine cold with the choke on. I need to crank first without choke and then choke and start.
I talked to Continental Engines and the guy said that when the tank is above the carburetor this tends to happen. I find this a little hard to believe since for nine years the engine was OK. Anyway, he recommend that I put a loop in the fuel line so that the high portion of the loop is at the top of the gas tank. He has seen this help on other engines. I figured it was easy to do and did it. So far its running fine, but I have very limited experience. Has anybody seen this trick/technique before?

 

[ponytug]

Dear Bob,

I've seen the trick, and it works, but like you, I am skeptical that it suddenly needs it. I wonder if the float seat is slightly worn.

All the best,

Peter

I should have kept quiet. I am having the same problem of flooding if I start the engine cold with the choke on. I need to crank first without choke and then choke and start.
I talked to Continental Engines and the guy said that when the tank is above the carburetor this tends to happen. I find this a little hard to believe since for nine years the engine was OK. Anyway, he recommend that I put a loop in the fuel line so that the high portion of the loop is at the top of the gas tank. He has seen this help on other engines. I figured it was easy to do and did it. So far its running fine, but I have very limited experience. Has anybody seen this trick/technique before?

 

[BobRip]

Dear Bob,

I've seen the trick, and it works, but like you, I am skeptical that it suddenly needs it. I wonder if the float seat is slightly worn.

All the best,

Peter

The seat is not replaceable. I did order a new needle for the float. The PT is running great, but the fuel level in the filter gets low a times.

 

[stray]

My PT 422 2003 model Robin engine started loping. Pretty bad this time. Any way to make a long story short I found that a plug or cap must had fallen or come out. I had cleaned and took apart and blew out but nothing helped. And then I noticed a port that look cleaner than it should be especially when it was below and outside the air filter. With the engine running and it loping as it was I reached in and put my finger over that exposed port. Low and behold the engine smoothed out and ran like new. Here are some pics to help explain.

 

[Gravy]

Do I see JB weld?

I love that stuff!

 

[BobRip]

Why replace the tamper cap? Now you cannot adjust it. I did not know of this cap when I cleaned mine. I guess I missed something.