27HP Command Pro running issues

[slomo]

Read head gaskets were replaced. Did you lap the heads and area where the gaskets sit, on the block? Just pulled one off a single cyl L-head. Was warped like all the others I've pulled.

Let It Idle for 45 minutes while I went to go grab more gas and came back to It still Idling fine.

Was this at slow or fast idle? Not recommended to idle one down unless yours is water cooled with a water pump and rad and a full pressure oil pump. If yours is air cooled, lower revs mean way less air for COOLING. Then we can talk about lubrication. Is your engine splash lubed? See where this is leading? Engine damage on the way. People think mowers will last longer if idled down, saving gas...... They are MADE to crank off at full revs until you are done with the machine.

I would pressure test the carb needle/seat to 7psi. Should hold for a min of 30 mins. Remove air filter FOR TESTING ONLY. See is she bogs while driving up hill or in a sharp turn.

Definitely flush and blow out the fuel tank. Replace all fuel lines and filter.

Pull the oil dip stick. Smell for fuel. Report back here if it does.

 

[bertsmobile1]

FWIW ( an that is not much ) I only buy aftermarket parts on line through Alibaba or MadeInChina or MadeInIndia.
All of these are set up for honest people and the vendors why can not hide behind 35 different screen names do not get paid till I reply that the goods were correct, arrived on time, in good condition & worked properly or 60 days after they were received ( assuming I was too lazy to confirm the goods ) .
Thus every thing was good and worked properly with the only problems being transit damage , and a photo sent to Alibaba scored a replacement sent express plus a full refund .
Note this is Alibaba and not AliExpress the latter being set up like Amazon & Ebay for scrap metal merchants to flog off scrap metal as working parts .

 

[Freddie21]

Most cheap carb, for me, show surging problems. So, if it corrects the original issue and causes surging, at least I know what the state of the original carb is. Some time a quick ream of the main jet solves the issue. And I agree, at least you have some internal repair parts. Just use as a trouble shooting tool.

 

[VRR.DYNDNS>BIZ]

So here It goes, I bought a Craftsman DGT6000 (1998) with the 27 HP Kohler Command Pro V-Twin a month ago knowing It had some Issues. It started and drove when I went to look at It and the engine sounded good so I bought It. Got It home and started messing with It and found It burned oil bad. Everyone said head gaskets so I ordered some genuine head gaskets from Kohler and replaced them. Oil burning stopped immediately. Put In two new plugs from Kohler and a new air filter and new fuel filter. Let It Idle for 45 minutes while I went to go grab more gas and came back to It still Idling fine. Started cutting and made 2 passes and It starts bogging bad and stalls. Will only restart with the choke on and would die with It off. Limped It back to the garage and fully disassembled the carb and found some debris in the bowl but that's It. Pulled every jet and made sure they all were clear. Now I haven't driven It yet. But It still has a problem that It had before I cleaned the carb. It seems to flood Itself at Idle. If I go to Idle for 5 seconds and then go to full throttle It chugs going to full throttle and while It's working It's way up to full throttle, It's blowing black smoke out the exhaust.

Float, needle and seat in carb.

 

[Freddie21]

I would also check the valve lash and value seats. Maybe do a leak down test.

 

[VegetiveSteam]

So here It goes, I bought a Craftsman DGT6000 (1998) with the 27 HP Kohler Command Pro V-Twin a month ago knowing It had some Issues. It started and drove when I went to look at It and the engine sounded good so I bought It. Got It home and started messing with It and found It burned oil bad. Everyone said head gaskets so I ordered some genuine head gaskets from Kohler and replaced them. Oil burning stopped immediately. Put In two new plugs from Kohler and a new air filter and new fuel filter. Let It Idle for 45 minutes while I went to go grab more gas and came back to It still Idling fine. Started cutting and made 2 passes and It starts bogging bad and stalls. Will only restart with the choke on and would die with It off. Limped It back to the garage and fully disassembled the carb and found some debris in the bowl but that's It. Pulled every jet and made sure they all were clear. Now I haven't driven It yet. But It still has a problem that It had before I cleaned the carb. It seems to flood Itself at Idle. If I go to Idle for 5 seconds and then go to full throttle It chugs going to full throttle and while It's working It's way up to full throttle, It's blowing black smoke out the exhaust.

I know I'm a little late to this party, but have you found a solution? If not, look on the side of the carb for a round cover with one or two small rubber lines going to it. That's the accelerator pump. When you find it, if it has two lines, find the line that has the hard bulge in it. Once you find that, start the engine and take a pair of needle nose pliers and gently squeeze off either of the lines being careful not to squeeze that bulge you found in the one line. That's a restrictor and you don't want to crush that.

If you squeeze off one of those lines and the engine starts to run better, that is typically a sign that the accelerator pump diaphragm has some sort of hole or breech in it and it is allowing fuel to go where it's not supposed to go, causing it to run rich. At that point you can either get an accelerator pump repair kit or put something in the hose to block it off. If you do the latter, you could experience a little hesitation when you move the throttle from idle to full, but it typically doesn't cause any issues while mowing. If it does, you can always remove whatever you used to block off the line and get a pump kit.

An accelerator pump diaphragm leaking causing a rich running condition is somewhat common on a Command vertical twin.