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Message |
    
Brad
Member
Username: Highhorse78
IA
Registered: 3-2010
Post Number: 20
| | Posted on Friday, July 23, 2010 - 6:07 pm: | 
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The Kohler k532 in my 400 has been having some issues lately. The original motor has roughly 670 hrs and hasnt been rebuilt. All of a sudden about a week ago the motor would bog down as if there was a heavy load on it when the choke was all the way in (off). This happens wheather it is cold or at operating temp. Seems to run great with the choke half out though. When running with the choke all the way in, you can see the governor linkage compensating for the load but is very sporadic. Motor seems to be running pretty hot too, as I am getting blisters in the hood decals around the muffler.
Thanks in advance for any help... |
Harold Goff
Member
Username: Jdalchemist
IA
Registered: 10-2004
Post Number: 719
| | Posted on Friday, July 23, 2010 - 7:01 pm: |
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Hi Brad,
It sure sounds like the engine is fuel starved or there is an air leak in the intake system. See if the carb to intake manifold and manifold to block connections are tight. Check for a pinched fuel line, and vented gas tank cap. Pull the fuel line off the carb, stick the line in a bottle (outdoors) and briefly turn on the key switch to run the fuel pump. Fuel should squirt out the fuel line. If not, check for blockage in the fuel tank strainer, bad fuel pump, etc. If there is good fuel flow, I would try some carb adjustment and then a new carb kit.
Harold |
Brad
Member
Username: Highhorse78
IA
Registered: 3-2010
Post Number: 21
| | Posted on Saturday, July 24, 2010 - 2:54 pm: |
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Thanks for the help Harold, its greatly appriciated. Just got around to checking fuel flow at the carb. Seems to be great, filled a 24oz pop bottle up to the bottom of the label in less than 10 seconds. Checked intake and carb connections, and they are torqued to spec. Still seems to be running the same. I'll go back later with a bottle of butane and rubber hose and try to pinpoint any other leaks. Also is there a spot to check vacuum, and if so how many inches it should pull to be within spec?
Thanks again... |
Harold Goff
Member
Username: Jdalchemist
IA
Registered: 10-2004
Post Number: 720
| | Posted on Saturday, July 24, 2010 - 5:42 pm: |
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Brad,
That butane test on the intake connections would be good. The crankcase pressure is checked on the dipstick/oil fill tube and should be about 12" vacuum for a water manometer--engine hot and full rpm.
Here are some other thoughts and fairly quick things to look at: I would check the carb high speed adjustment, as sometimes the air filter housing bangs on the needle top end. Is there any chance a blown head gasket is putting heat on the hood "muffler side". That would explain the loss of power, but I am not sure about the engine response to choking. A check of the points gap would be good, as a large gap would advance timing and cause engine overheating.
Hope you are high and dry, and I feel for the folks over your way who aren't.
Harold |
Brad
Member
Username: Highhorse78
IA
Registered: 3-2010
Post Number: 22
| | Posted on Sunday, July 25, 2010 - 9:56 pm: |
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Well Harold, I didnt get as wet as some in our county, but did have a small puddle in the basement.
Well, I started off by checking the points gap tonight. Although I replaced them about a year ago, I figured it wouldnt hurt to check. The gap was a tad small at around .016, so I regapped it to .02. Now I cant seem to get it to fire. Getting an intermittent spark here and there but still wont run. Suppose I'll pull it apart tomorrow and figure out whats going on. |
Scott Reynolds
Member
Username: Sreynolds
OH
Registered: 9-2007
Post Number: 317
| | Posted on Monday, July 26, 2010 - 10:26 am: |
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If you have not, I would perform the following just as I had when my engine was doing the same, soon after I bought it.
Rebuild the carb. A full rebuild. Everything. Have the machine shop bore the throttle lever bore and install bushings to tighten the space between the shaft and the aluminum body.
Replace the points, plugs and cables. easy enough.
Replace the head gaskets. One of mine was blown at a point. Also, resurface the head as it really needs to be clean and smooth. I replaced the bolts too.
Replace that coil with the Kirt's Point saver electronic module and individual coils.
Rebuild the governor assy. This baby controls the points. The parts in there will be in bad shape and will require replacement. That won't be cheap. All that small stuff is expensive. Pat's Small Engine on line store will have the stuff you need for the rebuild.
Convert the non pressure lubed governor to a pressure lubed governor if not already done so. The late models didn't have oil flow into the housing. All you need is some fittings and hose.
Time the gov to the engine when in stalling it and then tune it with the timing light.
Adjust the valves.
It takes a load of time and money but I will attest that once I had performed the above, my engine started great, had great power and ran well even with very worn pistons, rings and scored cyl walls. I lost 1/2 a quart of oil per two hours of operation past the rings, but that thing had some real power and started and ran great!
In fact it has no more power and runs no better now that I recently replaced the pistons, rings, turned the crank and generally replaced every item inside that crank case that moves.
Small gasoline engines are tough to contend with. |
Brad
Member
Username: Highhorse78
IA
Registered: 3-2010
Post Number: 23
| | Posted on Monday, July 26, 2010 - 8:00 pm: |
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Thanks for the help Harold and Scott. You were right Harold, it was the high speed mixture screw. Must have gotten bumped or turned in somehow. The points adjusting screw must not have been all the way tight, alowing it to move and not fire. Got that fixed and the carb all dialed in tonight. Runs great now. I'll just have to see if I still have an overheating issue.
And thanks for the suggestions Scott. Hopefully this winter I dig into the governor and add the points saver ignition mod. |
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