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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 13581
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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I have a super z 52 inch with a 27 hp Koehler motor getting

Customer Question

I have a hustler super z 52 inch with a 27 hp Koehler motor getting spark and gas but will not start
Submitted: 11 months ago.
Category: Small Engine
Expert:  JohnF2015 replied 11 months ago.

Hi,my name is***** will be assisting you.

What happens if you spray a little carburetor cleaner or fuel directly into the intake? Remove the air filter and spray in through intake and see if the engine will fire or start.

Customer: replied 11 months ago.
It pops
Expert:  JohnF2015 replied 11 months ago.

My thought is that you may have a push rod that has come loose or bent. I would check all four(two in each cylinder) behind valve covers. Easy to get access to them to check.

By the way this does have the Kohler Command series engine CV740 correct?

Customer: replied 11 months ago.
Wth waiting on a call!!
Expert:  JohnF2015 replied 11 months ago.

I see that you requested a phone call but there is an issue with payment and I was asked to not complete the call.

Someone from customer service should be trying to contact you in order to resolve the issue. In the meantime we can continue here if you would like.

Customer: replied 11 months ago.
it is the cv 740
Expert:  JohnF2015 replied 11 months ago.

Okay, so I would check the valves and more importantly the push rods.

Customer: replied 11 months ago.
OK all four of the pushrods are good and tight doesn't look like anything is bent
Expert:  JohnF2015 replied 11 months ago.

Did anything unusual or out of the ordinary happen right before you started having this problem?

Expert:  JohnF2015 replied 11 months ago.

Has the engine by chance backfired hard recently?

Customer: replied 11 months ago.
No it flooded out and I rebuilt the carburetor but it wouldn't start before that that's why I rebuilt the carburetor because it was flooding
Expert:  JohnF2015 replied 11 months ago.

Okay, did it get fuel into the crankcase when the carburetor flooded? If so, did you changed the oil?

Expert:  JohnF2015 replied 11 months ago.

Does it do anything at all when you try to start it without spraying fuel into the carburetor or intake?

Customer: replied 11 months ago.
No. The oil is clean.
Customer: replied 11 months ago.
No. it cranks or hits every now and then.
Customer: replied 11 months ago.
It won't start though.
Expert:  JohnF2015 replied 11 months ago.

You said that the push rods were tight which brings me to another thought. This engine has hydraulic valve lifters, if the lifters stick it will cause the valves to not close all the way which would cause the engine to not start and run properly which would also explain the pop when you sprayed carburetor cleaner or fuel into the intake.

The last time the engine run did you have any noticeable problems or issues?

Can you do a compression check on both cylinders and let me know what kind of readings you have?

Customer: replied 11 months ago.
I will have to continue this tomorrow evening
Customer: replied 11 months ago.
The lawnmower ran fine the last time it ran. It wouldn't start the next week to the mowed the grass and that's when it flooded out. It has plenty of compression. I know this machine has a lot of safety features don't know if something happened there or not.
Expert:  JohnF2015 replied 10 months ago.

I have seen that happen on occasion. The machine runs just fine one time, you shut it off, the next time you go to start it it just will not start.

I am looking for compression readings on both cylinders so that you can compare the two. The two cylinders should be withing 10% of each other per Kohler, if not then I would be looking for issues in the low side.

The other thing that I have seen is air or the fuel oil mixture gets into the hydraulic valve lifters and will not let the lifters compress as they should so that when you try to start the engine the valves do not fully close which would explain the pop that you are getting and a no start problem.

Customer: replied 10 months ago.
Sorry I haven't responded as I have been busy but will get back with you when I have time