Newbie looking for help with Honda GX240 that won't run

[Fish]

Could also be bad gas/water in the gas, but it is hard to tell from here.......

 

[PDX Man]

How does the compression feel by hand? Pull the rope and watch with the valve cover off. Go ahead and try to start, and watch for compression leaking, also watch the movement of the rocker arms, etc..

The compression seems normal when pulling the starter, but I don't have a ton of experience judging. The rocker arms are rockering and it looks like the valves are operating. I dpn't know how to watch for compression leaking.

 

[PDX Man]

Could also be bad gas/water in the gas, but it is hard to tell from here.......

Gas is fresh ethanol free. I have been running ethanol free for a couple of years. Actually since the last time I cleaned the carb. It lives outside under a tarp, but I don't think I've had water contamination.

 

[Fish]

If you start it with the valve cover off, you will see if you have a blown gasket. Let the fuel dribble out of the carb into a clean jar, and then hold the fuel in the jar up and look at it. If there is any water, you'll see it.
As far as checking compression, try rotating the engine by hand backwards. If you can do it, then your compression is weak.

 

[PDX Man]

Did you pull the air filter and spray starting fluid in the cab with the choke open, and then close the choke and give it a pull, do that and then post, that will be very telling as if it starts right up you have a fuel problem.
Start with the simple stuff.

I just tried that. I currently have the new chinese carb on. I can try it again with the old carb, but this is what I did:
1) disconnect kill switch completely to rule that out. Also the oil kill switch is disconnected, so the wire from the coil is not attached to anything.
2) Throttle open, choke open, gas flow on.
3) spray starter fluid into air intake (air filter off), close choke
4) Pull the starter rope
It doesn't start on the first or second try. Then it is the same behavior as in the videos. It will start if I put the throttle to idle and it will run for a bit and die.

 

[PDX Man]

If you start it with the valve cover off, you will see if you have a blown gasket. Let the fuel dribble out of the carb into a clean jar, and then hold the fuel in the jar up and look at it. If there is any water, you'll see it.
As far as checking compression, try rotating the engine by hand backwards. If you can do it, then your compression is weak.

I can rotate the engine backwards, but just barely. It goes easily up to a point and then gets hard. I can just barely overcome the resistance and get it to turn.

I did what you said and I don't see any water in the jar.

I don't know what I would be looking for with a blown gasket.

 

[backhoelover]

also need to check for bent push rod not letting valve open all the way. also take a tap measure and see how far the rocker is moving the valve. on am honda carb i have been lucky and have never had any problems. i keep 3 or 4 of each popular styles on hand at all time

 

[PDX Man]

running only when the choked is closed and stalling when opened has absolutely nothing to do with spark...
my guess is old carb needed a cleaning/rebuild, and the new carb is either jetted wrong for that engine or like I said before, its just junk...

I don't have a rebuild kit for it, so I am going to try to clean the old carb as far as I can without having to replace anything. Then I'll put it back on and report back.

 

[PDX Man]

I cleaned the old carb, but not completely. I cleaned the main nozzle and main jet, the sediment bowl, the float bowl, and sprayed carb cleaner everywhere I could reach. The float valve tip did not look worn.

I didn't touch the pilot jet or the pilot screw. I reassembled the carb and installed it using the new gaskets I got with the new carb. The bowl is leaking fuel. Obviously, I need new gaskets, but I don't think that should affect diagnosis, should it?

The behavior is more or less like before. It may actually be a bit harder to start with full throttle and choke. But no choke and idle throttle position it starts and runs perhaps a bit smoother than before. Open the throttle a little bit and it stalls right away.

I tried repeating the starting fluid experiment and it doesn't start on the first or second try. Or the third or the forth.

 

[Fish]

Did the rocker arms move approximately the same distance when turning the engine over, to see if you have a worn out cam lobe?

 

[PDX Man]

Did the rocker arms move approximately the same distance when turning the engine over, to see if you have a worn out cam lobe?

I saw that they both moved. Should I be able to tell just by looking? If I shot a video would you be able to see?

I don't think this engine has a lot of hours on it. I got the splitter used, so I don't know for sure how many hours it had on it, but it didn't look like it had seen commercial use. I've had it for 10 or 15 years. I don't think I use it more than 20 hours per year.

 

[woodtool89]

I cleaned the old carb, but not completely

should be completely disassembled, cleaned, and passages blown out...

I'm not sure if its been asked or not but... did this engine sit for a while since it was last run, and when you last ran it, did it run fine?

 

[bill saf]

PDX I looked at you vids again and read every post that you have put up the one thing that keeps coming up is how you try to start the engine! why are you trying with it at W.O.T wide open throttle? try this set the choke and just move the throttle a lil off from the stop or base about a fingers width, but before you do that run the polit screw in till i just hits bottom and out 2 full turns that is the starting setting for carb idle if it runs tune idle in or out for best idle when I say best its the fastest with the polit screw then set your base idle with the other screw and fine tune polit and it dont matter if its the oem carb or the AM carb. I like to set base idle about 1520

 

[Wonkydonkey]

In those pics of the carb bowl, they look more clean than I thought it would be.

There's sometink not right, I've watched both videos again, Yeh it seems like it don't want to start, and even less with the AM carb. But it did run/tick over in the 1st vid for some time

But having said this, it's like you just go from tick over to WOT , If you slowly open the throttle the engine should slowly increase it rpm.

I'm starting to think some linkage is not conected properly, from the throttle and carb Rev regulator
We have a Honda gen and a mate has a gx160 on a tiller/rotovator ,I,m gonna have a look to see if I can see if there's anything else it could be but in the meantime there's a vid on YouTube saying and showing how to do what I said before, I will see if I can find it

 

[Wonkydonkey]

And this one show how push out the other jet

 

[Fish]

I saw that they both moved. Should I be able to tell just by looking? If I shot a video would you be able to see?

I don't think this engine has a lot of hours on it. I got the splitter used, so I don't know for sure how many hours it had on it, but it didn't look like it had seen commercial use. I've had it for 10 or 15 years. I don't think I use it more than 20 hours per year.

Yeah, put up a video, if you can. Try and start it with the valve cover off too.

 

[PDX Man]

PDX I looked at you vids again and read every post that you have put up the one thing that keeps coming up is how you try to start the engine! why are you trying with it at W.O.T wide open throttle? try this set the choke and just move the throttle a lil off from the stop or base about a fingers width, but before you do that run the polit screw in till i just hits bottom and out 2 full turns that is the starting setting for carb idle if it runs tune idle in or out for best idle when I say best its the fastest with the polit screw then set your base idle with the other screw and fine tune polit and it dont matter if its the oem carb or the AM carb. I like to set base idle about 1520

In those pics of the carb bowl, they look more clean than I thought it would be.

There's sometink not right, I've watched both videos again, Yeh it seems like it don't want to start, and even less with the AM carb. But it did run/tick over in the 1st vid for some time

But having said this, it's like you just go from tick over to WOT , If you slowly open the throttle the engine should slowly increase it rpm.

I'm starting to think some linkage is not conected properly, from the throttle and carb Rev regulator
We have a Honda gen and a mate has a gx160 on a tiller/rotovator ,I,m gonna have a look to see if I can see if there's anything else it could be but in the meantime there's a vid on YouTube saying and showing how to do what I said before, I will see if I can find it

Yes, I normally start all my engines from cold with WOT and choke, then open the choke when it starts. I just checked the honda manual and see that is not the recommended procedure. I'll have to try to change a bad habit. Did I do any damage? This particular engine, moving the throttle from idle slowly, it doesn't start increasing the speed until the lever has moved a bit. While diagnosing this problem, while it is running at idle, I have tried moving the throttle a tiny bit at a time.As soon as it gets to the point where it wants to speed up, it dies.

 

[Wonkydonkey]

I don't think you have done any damage starting with wot,

It's when your trying to work out what's wrong, it's 1 or another equation that needs to be eliminated.

An engine needs spark, air, fuel, compression

I still think It's fuel starvation, get a spray bottle and spray fuel in the carb while it's running, and try and open the throttle.
This way your providing the fuel and opening the throttle provides the air. And you have a spark because it starts and runs a bit.
It may run rough, but as soon as you stop spraying fuel, if it dies then it's fuel starvation.
If you watched the vids I linked, the 1st one shows him dumping x amount of fuel in the air intake. This is what I would do to get the engine started, which saves pulling the cord and saves my arm, by spraying you can see/hear every time you spray the engine should Rev up. If it don't then fuel is not the problem.
Anyhow, it's up to you to try, and if it don't work it must be something other than fuel.

And/or you can do it with the other AM carb,

If you can keep it running by providing the fuel from a spray bottle , that indicates not enought fuel from the carb,
The only othe thing I can say is change the spark plug for a known working one or test the plug in another machine,
Cheers

 

[bill saf]

WOT at start just floods the spark plug. what I will say is put a new spark plug in it. Ill bet the plug when it gets some temp its shorting out not as( common ) as carb problems or no spark. but we know the engine will idle for a short time or till you put gas to it. Did you adjust the polit screw 2 turns out from bottom? that will put you in the ball park and go from there. if the spark plug does not take care of it Ill eat crow because the only thing that would be left in the electrical sys is the trigger circuit in the coil and temp will do the same as spark plug.

 

[PDX Man]

And this one show how push out the other jet

As I said above, I did that level of cleaning in those videos and a bit more, like the sediment bowl and the carb passages I could access without removing the setting screws. I know I should do a full cleaning, but I'll have to wait till I get a rebuild kit or at least all the gaskets and washers. Anyone have any recommended online source for the rebuild kit and the carb gaskets?