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Gasoline is pouring into the crankcase from the left cylinder. The left intake manifold gets cold and frosty while the right is normal. I rebuilt the carburetor. Compression is about 170 on both cylinders. Can someone tell me what the heck is the problem.

Which engine and what carb
Single barrel or twin barrel ?

Did you replace the needle and seat?

bertsmobile1 said:

Which engine and what carb
Single barrel or twin barrel ?

Click to expand...

Its a Toro 708cc model 127-9040 with a 2 barrel carb.

MParr said:

Did you replace the needle and seat?

Click to expand...

I didn’t replace the needle and seat but how could that affect just the left cylinder?

I even replaced the left head gasket thinking that could be the problem, with no avail

Here’s the schematic and parts for the carburetor.
Doesn’t matter that this is from the ZX5400. It’s the same engine and carburetor.

Billjean46 said:

Its a Toro 708cc model 127-9040 with a 2 barrel carb.

Click to expand...

On a twin barrel cab, one side not running can be because the carb is bad on that side
Things like the main jet not installed or blocked on one side only.
With a runs on one side only problem the trick with diagnosis is to start by separating fuel from ignition

Start with stuff you can see, like valves moving
Slip the rocker covers off & plugs out then rotate the engine by hand at least 2 full revolutions while watching each side
The rocker movement should be identical, inlet to exhaust and left to right
B0th vales should move the same distance and sit at the same position when slack.

Next try without the kill wire on the magnetos ( check it will stop from the fuel solenoid )
NExt swap the coils over , note they have to go in the same way up
Problem shifts side = bad coil

No difference then the problem is in the carb

@bertsmobile1
I am beginning to think along those line.
@Billjean46
I have linked to a PDF of the service manual. You can copy or download it.

Thank you for the service manual info. I've been looking all over for one. Can't get one from Toro. I'll check out the carb again and get back!

MParr said:

@bertsmobile1
I am beginning to think along those line.
@Billjean46
I have linked to a PDF of the service manual. You can copy or download it.

https://www.tractorforum.com/attachments/loncin-v-twin-pdf.70838/

Click to expand...

Awesome! Do you know what year this motor is? It looks really similar to mine which is a 2021 Kohler (22hp). I have a 34" Toro Timecutter.