Air source on my Toro Timecutter SS4235

andyboy

Member
Joined
Jun 6, 2010
Threads
1
Messages
14
I have a Kohler KT725 2 cyl. engine on my Toro Timecutter SS4235. I have an issue with where the air is drawn from for the engine. It seems to be kinda ducted up past the exhaust manifold before entering the air cleaner enclosure. I say kinda because this path is not airtight by any means. The only benefit I can see to that is that the air comes in warmer than if it just came in anywhere else. My concern is that on this mower this is about the worst spot you could chose to get air from. Except for inside the mower deck this is the dustiest place to draw air from especially during leaf chopping season. . I was thinking of sealing the existing air cleaner openings and adding new ones on top. Kinda like air scoops on a muscle car. Any thoughts?
 

Attachments

  • Toro rear shot with cover.jpg
    Toro rear shot with cover.jpg
    226.4 KB · Views: 58
  • toro high rear shot of engine wo cover.jpg
    toro high rear shot of engine wo cover.jpg
    473.1 KB · Views: 57
  • toro overhead shot air filter.jpg
    toro overhead shot air filter.jpg
    278.3 KB · Views: 58

MParr

Lawn Addict
Joined
Jul 2, 2021
Threads
6
Messages
1,421
Personally, I wouldn’t do it.
Blow off your mower after each mowing. A leaf blower will be good enough.
Remove the filter cover and filter and wipe the inside out with a damp rag.
Buy you a new filter with the green foam prefilter and use that setup. The prefilter needs to be washed and oiled every 25 hours.
It looks like you need a new cover too.
 

ken2

Active Member
Joined
Mar 30, 2015
Threads
10
Messages
74
If there is no dirt inside the filter. You shouldn't have any problem. It looks like the same engine that is on my bad boy. Kohler makes a high performance air filter system that sucks the air in through a little precleaner that sits on top of the engine.
 

7394

Lawn Addict
Joined
Sep 5, 2014
Threads
84
Messages
4,608
Intake air is actually cooling air coming off of the flywheel fan just above the heads.
Yes it is, as witnessed by pic # 3 of your overhead shot.
 

MParr

Lawn Addict
Joined
Jul 2, 2021
Threads
6
Messages
1,421
After looking at the photos, I’d say you need a new airbox and cover too.
 

andyboy

Member
Joined
Jun 6, 2010
Threads
1
Messages
14
Thanks for the comments.
I already use the leaf blower on the mower after each mow.
The airbox and cover are in factory condition except for the wingnut that I replaced one "latch" with. They don't but should sell the
"latch" separately. The whole cover was $27 and since the "latches" like to get caught on brush and shrubs I'm better off with the way I have it. It's airtight.
I removed the plastic engine shroud and found that the air is not ducted at all and is sourced from around the engine block with all the dust. I thought maybe the design was to pull pre-heated air from around the block but I see that isn't true or was pooorly executed.
With shroud off I can evaluate my options better. I am probably going to seal off the current airbox openings and duct air from the topside of the engine. Or maybe justy cut holes in the cover and provide a screen from leaves etc. from falling down into the cover.The only requirement I see is to provide at least the same volume of air.
My primary concern is to first do no harm.
 

fixit1ddh

Well-Known Member
Joined
May 5, 2010
Threads
1
Messages
112
I have to of the KT-735 A 2015 & 2017. THE 2015 is just like Yours. The 2017 has half as many holes from blower housing. The 2017 has holes from bottom by the carburetor. The 2017's air filter gets twice as dirty. As compared to the 2015. Mowing the same grass, 2017 is my Wife mower and there identical zero turns. My guess OL Kohler was not selling many air filters. If it was mine I would not change a thing.
 

andyboy

Member
Joined
Jun 6, 2010
Threads
1
Messages
14
As my time is plentiful this time of year I proceeded as shown. It took about 20 minuets to implement. The fittings are off the shelf in the electrical department.
I raised this issue a few weeks back and did not get a lot of support. Did I let that stop me? No Sir! :)

This is flexible steel electrical conduit. I did not want something rigid because I go under low limbs and/or sometimes when I turn the engine goes into shrubs. So far no problems to report. It is leaf chopping season in NJ that creates a lot of dust. I want to wait for leaves to dry out a little before using it some more and delivering my verdict. I plugged the original air intake and these hoses feed the air filter housing above where the air was being drawn from. The volume of air delivered is about the same as it was.
The hoses can easily be swapped for longer ones and will let me easily play with where I pull air from. Behind the mower is not the best but higher is better. The hoses will also let me play with feeding some propane from a handheld tank into the air supply when I get bored.
I am considering putting another hose from in the seat bottom to experiment with the occasional methane boost.filter housing stock clean.jpgfilter housing modified with Flexible Aluminum Conduit fittings.jpg

And the hoses wobble around like John Belushi's bumble bee costume from SNL.
Toro with Flexible Conduit intake.jpg
 
Last edited:

7394

Lawn Addict
Joined
Sep 5, 2014
Threads
84
Messages
4,608
Wow, very original..
 
Top