Unscheduled maintenance on repowered Scag Tiger Cub

Mad Mackie

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Hi Troops,
Repowered Scag Tiger Cub was showing an oil leak on the left side under the starter. Cleaned it up and found that it was the drain valve that I had installed when I installed the new engine, my bad!!!! Removed the engine, removed the drain fitting and drained the oil. The engine still had the muffler installed so it set nicely on the crankshaft and the muffler. I ran a pipe tap into the hole to clean it. I think that there was some disruption in the thread that had caused the drain fitting to feel as if it was tight. Anyway, I deepened the hole slightly with a pipe tap with grease in the flutes to catch any aluminum chips from taping, cleaned it up, reinstalled the drain valve and reindexed it from the 3 o'clock to the 9 o'clock position where a drain hose can be connected away from the muffler.
I have an oil withdrawal system but I chose to reinstall the drain valve and not a pipe plug.
While I had the clutch off, I checked it with an Ohmmeter and it was 2.3-2.4 Ohms with two meters that have zero scale option. This clutch should read 2.8-3.2 Ohms!! I reinstalled the clutch, started the machine, did some mowing, but noticed a system voltage problem on the aftermarket monitor. Another voltage regulator had failed. I installed the regulator that had been on the old engine and did an ammeter check on the clutch. With the clutch fairly cool, the current draw was 6-7 amps and as it warmed up the amp draw decreased some but not much. This is out of spec and could be the reason for the regulator failures. Tomorrow I'll buy a new clutch, 510 hours on this original clutch. 45 hours on the new Briggs 30 HP Cyclonic engine, 2nd regulator, original regulator from old engine presently on the engine.:confused2::eek:
Mad Mackie in CT
 

Mad Mackie

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Mowed some this week with the same clutch and the regulator from the old engine, no problems. Next week I'll need to do my customer cycle and time will tell!!!
I want to talk to Briggs & Stratton about what I feel may be a bunch of problematic rectifier/regulators, but this may never happen. Anyway I have found a dealer that still has the old P/N regulator in stock and I'm going to buy it. After 50hours has passed on this new engine, I'm going to switch to synthetic engine oil, probably 10W30, but I was looking in my oil stash today and I still have several gallons of 5W30 synthetic, so I'll use it up!!!
Mad Mackie in CT
 

KennyV

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Your clutch is drawing a bit more than it should... But It is not so much that it is going to fail just yet...
The rectifier will Not be failing because of the clutch, that rectifier will handle well over 7 amps... there is somerhing else causing your rectifier failures... poor ground, bad run of parts... something else, but Not a 10% to 15% increase of 1 electric load.
I would replace the rectifier, and watch the voltage... The clutch is Very tuff and should hang in for a Long while... :smile:KennyV
 

Mad Mackie

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Hi KennyV,
I have a Signal Dynamics Heads-Up Voltage Monitor on this machine and this has been giving me indications of charging system problems. I also confirm by checking with a voltmeter. The regulator from the old engine was USA made, the regulator that came on the new engine and the replacement were China made.
Battery was new last fall, Interstate 425 CA/350 CCA, same gravity across all cells, charges OK on battery charger.
I will continue to use this machine and watch the voltage monitor and periodically check the clutch continuity.
Although the new engine is 30HP (the old engine was 26HP), it uses less fuel and the air filtration system is much better, so overall I'm pleased with this package. :thumbsup:
Mad Mackie in CT:laughing::biggrin::smile:
 

Mad Mackie

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Was just looking at my machine and found only two bolts holding the cooling baffle onto which the regulator is mounted. The bolts are tight, but I'm going to makeup a jumper wire to better ground this baffle.
 

KennyV

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The Heads Up is a good monitor...
I suspect you are seeing green & flashing green with engine running??
With a good rectifier;
Is it ever Red or flashing Red with engine running?
Do you ever have enough electrical load to give you a yellow with engine running?

a bit more HP will run more efficiently, especially if a lower HP engine is loaded near its peak torque output...
:smile:KennyV
 

Mad Mackie

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As the regulator starts to fail, the Heads Up monitor goes from steady green, to steady amber, then periodically back and forth between amber and red. I have been keeping my small digital multimeter in my pocket as I'm mowing to confirm what the Heads Up monitor is telling me. With the regulator from the old engine installed, I get steady green for hours of operation. To change the regulator, the debris screen, the rotating screen, and blower housing have to be removed in addition to moving aside the fuel pump and oil cooler as the wiring on the stator is too short. So I want to have a good charging system as the plastic housing will not take repeated removal and reinstallation of the metal screws as I have a tendency to overtignten things!!!! One of my past fellow mechs named me "Vice Grip" among other nicknames that I won't mention here!!!!:laughing:
I am liking the added HP!!!
Mad Mackie in CT:laughing::biggrin::smile:
 
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