Kohler 36hp - running strange

[Shootertexas]

I recently acquired a Garage Queen Craftsman 54" cut lawn mower with a Kohler 36 hp motor. I really haven't had the time to really get into why it runs like it does. I though I would come on here and see if anyone had any similar experiencs and migh be able to guide me where to start.

I have taken the plugs out and re-gapped them, checked the air filter and checked the fuel flow.

It starts just fine with just a bit of choke and seem to be idling fine, no smoke (white or black) or the smell of un-burnt fuel.

Here's the strange part.... When running at full power (i haven't run it enough to actually tell if that's the only time it does it) it runs ok or so it seems but every so often the engine will gain power (not any higher RPM) and quietened down a bit for a few seconds before returning back to its original sound.. It's very hard to accurately describe.

Coil packs? Carburation? Valve Lash? Anyone else had a similar experience? TIA

 

[Auto Doc's]

The engine identification information off the label is needed for accurate information.

Does the engine lose power when this occurs?

Is this water cooled, and you are just hearing the cooling fan cycle on?

 

[Tiger Small Engine]

I recently acquired a Garage Queen Craftsman 54" cut lawn mower with a Kohler 36 hp motor. I really haven't had the time to really get into why it runs like it does. I though I would come on here and see if anyone had any similar experiencs and migh be able to guide me where to start.

I have taken the plugs out and re-gapped them, checked the air filter and checked the fuel flow.

It starts just fine with just a bit of choke and seem to be idling fine, no smoke (white or black) or the smell of un-burnt fuel.

Here's the strange part.... When running at full power (i haven't run it enough to actually tell if that's the only time it does it) it runs ok or so it seems but every so often the engine will gain power (not any higher RPM) and quietened down a bit for a few seconds before returning back to its original sound.. It's very hard to accurately describe.

Coil packs? Carburation? Valve Lash? Anyone else had a similar experience? TIA

I doubt it is 36 horsepower, maybe 26 horsepower. Sounds like it is hunting and surging. Typically a dirty carburetor, and an all too common problem.

 

[slomo]

Post a video on youtube and link it here. We need to hear it.

 

[Shootertexas]

I doubt it is 36 horsepower, maybe 26 horsepower. Sounds like it is hunting and surging. Typically a dirty carburetor, and an all too common problem.

You are correct, it is a 26hp, my fat fingers and slow brain did not catch the typo.

 

[Shootertexas]

Problem solved.... It had the original DSAI coils in it. I switched it over to MDI. It now runs like a champ.
With only 226 hours on a 2009 machine, it was well worth the 40.00 for the kit,

 

[Auto Doc's]

Glad you resolved the issue.

There is way too much experimental garbage being put on machines and even vehicles without proper stress testing to prove they are worthy. Companies are too quick to rush products to market, they always have been by the vast majority,