28M707-1166-E1 trouble starting

[Rivets]

If you assemble the float with the needle and seat in place, the float should be level. If the float is higher on the side opposite the float pin you will have a lean starting and running condition. More than likely the seat has swollen, causing the needle to shut of the fuel to soon. If you find this is the case you can try to resolve the problem by replacing the needle and seat, making sure the seat is installed properly. Other solution is to replace the carb. There are tricks to adjusting a plastic float, but I don’t post them as an amateur can easily ruin the float if not done correctly.

 

[bertsmobile1]

And THIS is the method of cleaning out the idle circuits for cabs that are sealed
Back in post # 3 scrubby posted a link to the photo instruction for cleaning Walbro carb which actually has that link in it but a lot fail to see it
IF your carb has removable idle jets and not having a solenoid usually means it was supplied with removable jets, these ned to be cleaned and adjusted in order to start easily .
Unfortunately you did not put a side view photo of the carb so I can not identify which one you have.
Also note in the instructions it shows where the pick up for the idle circuit is in the main jet tube
If you have a can of any goo, carb cleaner / WD 40 etc with a long straw poke it into the pick up hole then looking into the engine end spray down the hole
You should see the fluid coming out of the tiny holes on the left ( right when viewing from engine end ) side of the carb throat shown in step # 24 under the yellow dots in the above mentioned cleaning instructions .
You should also see goop coming out of them when sprayed down the pilot air path shown in step # 13 outlined in yellow
Everyone usually checks the pilot air passage because it is there easy to see but most forget about the pilot fuel passage cause you can't see it easily

The other method to check it is working is to fill the float bowl and blow low pressure air down the yellow hole only and check for fuel ( or what ever you put in the bowl ) coming out of those holes and by low pressure we are talking 5-10 psi of via one of those cans of compressed air for dusting cameras and electronics .

 

[micahmesser]

Mine is a Walbro LMT with a permanent idle jet, where the idle adjustment screw is. I did try by best to clean that out by spraying carb cleaner into the idle adjustment screw hole where that idle just passage is. I will do it again and check them as you mentioned to see if they are blocked. If they are blocked, I will probably replaced the ball as mentioned. I have the tap set already when I was working on a generator.

 

[riceski@gmail.com]

REPLACE CARB

 

[Gord Baker]

Double check that the Flywheel Key is not partially sheared on Crankshaft.

 

[Bellcrank]

Good Morning!

I have been struggling to get my mower to start properly without injecting either carb cleaner into the carb or gas directly into the chamber. What have I done to fix this issue?

1. Cleaned the Carb (3x now) - this included removing everything from the bowl and tube, physically cleaning all the jet holes and using both carb cleaner and compressed air
2. Replaced the intake manifold (small crack that eventually became a big one after removing carb)
3. Cleaned chamber according manufacture instructions
4. Checked cold compression (reads 100psi both without and with oil)
5. Charged battery
6. Checked teeth of flywheel
7. Replaced magneto (Original was extremely rusty and the spark was a little weak)
8. Checked spark plug gap (0.30) and resistance (resistance was within tolerance, 6,000 ohms I believe if my memory serves me right)
9. Checked spark - sparking like a mad man
10. Cleaned alternator ring of rust
11. Replaced fuel line with new fuel line
12. Dried out fuel tank and replaced with new non-ethanol fuel
13. Drained all oil and replaced with new oil

I should note that I was able to get the engine to start on the second turn after cleaning the carb for the third time. It started right up but since then it won't start. This makes me think it is the carb but after so many times cleaning it, I am just not sure that is the issue. The carb was replaced two years ago with a Briggs and Stratton Walbro. When I cleaned the carb the first time there was some gunk in the carb but none of that showed up after the first cleaning.

Any suggestions?

With carb installed on mower and ready to start the carb butterfly is by default open. Wide open. If not, good luck get'n it started.Linkage issues or adjustment can cause this.

 

[micahmesser]

REPLACE CARB

It is a brand new carb from a year ago.

 

[micahmesser]

Double check that the Flywheel Key is not partially sheared on Crankshaft.

This is something I have thought about but would that cause it to only start with a squirt of carb cleaner or gas in the chamber? Seems like it would also run poorly when started but it runs great.

 

[wtjackso]

Replace the carb. They are not that much money and all indications are for whatever reason, their is something defective internally with your current carb.

 

[Rivets]

With the carb properly installed the throttle butterfly should be wide open, but the choke butterfly should be fully closed when starting.