Polaris ATV Forum - View Single Post - Starter Stays Engaged
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post #10 of (permalink) Old 08-09-2012, 09:20 AM
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Join Date: Apr 2010
Location: Post Falls, ID
Posts: 503
Don’t know why these starters cause so much concern. Their operating characteristics are due to their design and are consistent with other small engines. There’s no fix, no BS, no damage will result if their operation is within design parameters and there’s nothing the dealer can really do about it.

Nearly universal in automotive applications are “positive shift” type starters where the solenoid when energized physically moves the starter drive against spring pressure into engagement with the flywheel. At the same time, the starter motor is powered through (large) electrical contacts. When the key is released and the power cut, the springs retract the drive (near instantaneously) and the unpowered starter motor winds down without interaction. Yes, there are variations, but that’s the general idea.

The “Bendix” drive type starter dates back to at least the ‘20’s. This type involves a drive unit which operates on centrifugal force to engage the drive gears when the starter motor is energized. In this type, the solenoid is really nothing but a large relay and does no mechanical work. Once energized, the starter motor begins to spin, turning the drive through a gear. The weighted drive unit takes a moment to catch up which causes the unit to spin outward toward the flywheel on grooves machined in the shaft while overcoming light spring pressure. On initial engagement, the non-moving flywheel forces it to fully “unwind” into full engagement at which point the starter motor begins to turn the flywheel and the engine spins. When the power is cut, the starter motor spins down and spring pressure (eventually) overcomes centrifugal force and withdraws the drive. As you’ve noticed, there’s a delay in disengagement and several factors including engine speed can cause the time to vary a bit. In any case, this type of starter is nearly universal in small engine applications and isn’t generally overly troublesome.

There are a couple of other factors that affect Bendix drives. They’re sealed in the recoil starter housing and get no love or lubrication. If you have a machine with a recoil starter (probably ’08 and prior), there’s a tendency for moisture to get into the housing through the rope hole and if left in will cause the Bendix to rust which quickly ruins it. If none of the internal parts are broken, they can sometimes be saved, but operation in my experience from that point forward has always been erratic. Polaris sells replacements (very expensive) and all the individual parts. And, aftermarket Bendix drives from several countries are available from numerous vendors. Some have better reputations than others. (Most are Asian or South American.) If you ever have the recoil starter housing off the engine (whether it be a real one or a “blank”), the Bendix is easily removed for cleaning and lubrication. (Don’t forget to give the bushings in the housing and engine case a dab of grease and be sure to put the thrust washer back in the correct place.) Bendix drives that are on the way out often won’t engage at all and the starters just spin. Sometimes they’ll catch after two or three tries, but it will likely get worse over time. I’ve never had one refuse to disengage completely, but others here have reported that happening. In my experience, they’ve lasted for years with minimal attention. Your method may vary.

MarkC - Spokane, WA USA
"Long live the orphaned Hawkeyes and mid-size Sportsmans"

Last edited by 1of7627; 08-09-2012 at 09:23 AM.
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