How to test a flywheel?

[OCD Solutions]

Is anybody aware of a way to test a flywheel? There should be a way to spin it up to speed and measure the output pulse.

I know JSS has a system , I was just wondering what other's take was on this.

 

[superjetkev]

see if your flywheel key will stick to it?? if it does your good no?? ive never tested a flywheel like you have described, but i always check to see if its still magnetic and ive never had a problem. maybe your talking total loss flywheels...or i just dont understand what your getting at.

 

[OCD Solutions]

I'm just speaking in general, over the years I have heard many people suspect that they had a bad flywheel. I just installed a used RAD flywheel on my SJ and suddenly I'm chasing gremlins. There are definative tests for everything, there must be one for flywheels.

 

[superjetkev]

intresting. at the seadoo dealership i worked for an employee dropped a flywheel and it was no good after. it wasnt magnetic anymore after it dropped i guess...i didnt see it tested myself but thats what he said...and thats why i always check to make sure they are magnetic b4 i install. but if there is an actual way to test one id like to know how its done too!

 

[SUPERJET-113]

I'm just speaking in general, over the years I have heard many people suspect that they had a bad flywheel. I just installed a used RAD flywheel on my SJ and suddenly I'm chasing gremlins. There are definative tests for everything, there must be one for flywheels.

Take off the flywheel and check the back for cracks, a loose or cracked hub, or something that could be throwing it off balance.

I had a hell of time once trying to figure out why I had a intermittent spark on my SN.
Well after a lot of testing/checking/swapping parts, it turned out to that my Jetinetics alum charging flywheel of 8 years had formed some cracks by the hub on the backside and was throwing the flywheel off center sometimes and therefore loosing spark via the air gap being to big on the trigger coil. That was a fun one to diagnose!

 

[#ZERO]

The 6M6, 61X, 62T, 64X and aluminum charging flywheels all have four magnets inside; just use a piece of steel and see if it sticks in four separate spots. If a magnet is cracked it will be much weaker in one four sections.

The 62T stator AC voltage specs are on page 42 and 43 of the XL700 service manual. http://www.mediafire.com/file/wdzzjzymwni/YamahaXL700 Service Manual.pdf

There are cranking and running voltage specifications for each coil unit at different rpm's on this service manual.

 

[WFO Speedracer]

Usually the cranking tests are for the stator but you are correct if the magnets were weak on the flywheel it would test low on cranking voltage as well.