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Main Area => General GS500 Discussion => Topic started by: ruig on August 06, 2018, 11:40:46 AM

Title: Bottom end noise - Rod knock?
Post by: ruig on August 06, 2018, 11:40:46 AM
Hello everyone,

I bought a cheap 98 GS500E with 9900km that was only running on the RHS cylinder.

I suspected it was carb problem so I proceded to do a clean-up. As I was dissembling the carbs I noticed that the pilot jets where stripped and that all of the LHS carb O-rings where completly dry. Specially the fuel input to the bowl the O-ring was so dry that the brass piece did not hold in the carb and would probably be the origin on a carb flood problem.

I ended up doing a full rebuild of the carbs and bench syncing the carbs.

Put the carbs back on the bike, started right up on two cylinders but it now showed this obvious knocking/dinging metallic sound coming from the left side of the engine:

Video:
https://youtu.be/DP6mvVt3HPQ

could this be rod knock or a more simple problem?
Title: Re: Bottom end noise - Rod knock?
Post by: The Buddha on August 06, 2018, 02:42:57 PM
Left side = starter clutch, alternator and other crap. Especially in the back 1/2 or even the crank location - right at the middle of that bulge where alternator is.
Front of the engine is counterbalance bearings.

Crank bearings will usually make a noise when trailing throttle but go away at open throttle especially under load.

Cool.
Buddha.
Title: Re: Bottom end noise - Rod knock?
Post by: Joolstacho on August 06, 2018, 04:22:07 PM
It's that good ol' starter clutch again...
Title: Re: Bottom end noise - Rod knock?
Post by: ruig on August 07, 2018, 03:30:31 AM
Quote from: The Buddha on August 06, 2018, 02:42:57 PM
Crank bearings will usually make a noise when trailing throttle but go away at open throttle especially under load.

it's sort of noticeable in the video that when I accelerate the sound goes away. The moment it stabilizes RPM it comes back.

I'll check the starter clutch ASAP. What can cause it go go bad in such a low mileage bike?