Honda 50 Ticking/Whirly Sound

[ahicks]

Can you shoot a video so we can hear it well enough to get a better idea of what you're dealing with?

 

[Noah4200]

Here’s another one

 

[Noah4200]

There’s no external bearing under there correct just crank seal and internal crank bearing as shown in this pic.. Just trying to figure out any other cause

 

[ahicks]

Have you had this engine for a while and this noise just appeared all of a sudden, or is this a new purchase you are straightening out? Did it happen right after servicing like the one fellow wrote in about? Is the engine making the oil dirty quickly after a change, or is it remaining fairly transparent? Have you pulled the valve cover off and run it like that to see if the noise is any louder? Messy for sure, have some rags or paper towel on the ready, but may tell you quite a story in a hurry!

I have a lot of experience with these 40's and 50's. IMHO the noise I hear is to light to be crank or rod related. If there's no contact being made under the flywheel, and no signs of magnet movement (dust), I suspect it might be something in the valve train. Is there any chance the belt is dragging/rubbing on something? Any signs of that available on the belt?

 

[Noah4200]

It’s a motor I just bought that had been sitting. It’s def coming from up front under the flywheel. I’m thinking it’s hitting and that I need to look harder at the contact. Going to color everything with a sharpie and see what is revealed.

 

[Noah4200]

Honestly…sounds like I need to just order a new flywheel. A used one on eBay would likely have the same issue. This sucks…already spent 500$ on parts going thru this motor. I’ve read about 10 posts and I’m sure it’s the flywheel. With no way to repair like other brands…it’s just going to get worse and ruin the coils and might cause major damage if it locks completely. Don’t really want to file down my coil pickups …already feel bad about trying that on one corner. Whole situation sucks…will have 1000$ in parts in a 25 year old motor and haven’t even touched the lower yet…

 

[ahicks]

Honestly…sounds like I need to just order a new flywheel. A used one on eBay would likely have the same issue. This sucks…already spent 500$ on parts going thru this motor. I’ve read about 10 posts and I’m sure it’s the flywheel. With no way to repair like other brands…it’s just going to get worse and ruin the coils and might cause major damage if it locks completely. Don’t really want to file down my coil pickups …already feel bad about trying that on one corner. Whole situation sucks…will have 1000$ in parts in a 25 year old motor and haven’t even touched the lower yet…

Throwing parts at an issue with no proof they are going to fix a thing is going to amount to a series of expensive lessons. A noise like you have should be EASILY seen when the flywheel is pulled -IF- that's actually where the noise is from.

Then, I would not ASSUME all of the used flywheels available are junk. The loose magnet issue is actually pretty rare. I've been through a hundred or so of these 40/50's and never had one! It's just something I keep in the back of my head as a potential issue.....

Don't get discouraged. You can get through this. Willing to bet that when you do find it, it'll be some little DA problem you've been looking at the whole time. These motors are NOT that picky to get right......

 

[Noah4200]

I’ve already been under there and tried to lightly file the corner of the pickup…didn’t work. These pics are what I found before I did anything. It’s def a loud metallic pinging at flywheel speed…wouldn’t you say it’s hitting?

 

[MattFL]

That definitely sounds like something hitting. Try your idea, paint the magnets and edges of the coils, run it for a few then look for missing paint.

 

[ahicks]

I'd say it's been hit for sure, but to make the noise you're messing with, I would think there would be MUCH more evidence very clearly visible. With the plugs removed, you should be able to feel this noise when turning the engine over by hand.....

Maybe try that with and without the belt installed - just realize if you hit the starter with no belt you're going to bend valves for sure. You would only be able to turn it a few degrees each way..... -Al

 

[Gcaus2343]

I’ve already been under there and tried to lightly file the corner of the pickup…didn’t work. These pics are what I found before I did anything. It’s def a loud metallic pinging at flywheel speed…wouldn’t you say it’s hitting?

Hey mate I have just bought a motor with similar noise let me know what you have found I’m doing some investigation myself.

 

[Noah4200]

So I put the new flywheel on and it’s super quiet and the slight misfiring after running awhile is gone!!! Get a new flywheel. I see guys running them with the hitting -this WILL affect running!!! You can’t have thousands of strikes a minute with no consequence. Shop around and find a new one for around 400$. Like butter now!

 

[km1125]

Looks like you "solved" the problem, but I'm wondering what the actual difference is between the new and old flywheel? There wasn't anything loose in the old flywheel was there? Is there more clearance in the new flywheel? Slightly thinner magnets?

For other with noise issues, something here to consider. Maybe take a GOOD video (with high frame rate) and see if some analysis could lead to clues. Using one of the prior videos posted, I put it into a video editor and you could tell the "tick" was happening once per revolution, if that engine was running at around 750RPM when the video was done. If that video was done at 60FPS or faster, you could have more detail, and if the flywheel was marked you'd know exactly where the noise corresponded with the position of the flywheel.

Here's a graphic to try and illustrate the idea:

 

[Noah4200]

Looks like you "solved" the problem, but I'm wondering what the actual difference is between the new and old flywheel? There wasn't anything loose in the old flywheel was there? Is there more clearance in the new flywheel? Slightly thinner magnets?

For other with noise issues, something here to consider. Maybe take a GOOD video (with high frame rate) and see if some analysis could lead to clues. Using one of the prior videos posted, I put it into a video editor and you could tell the "tick" was happening once per revolution, if that engine was running at around 750RPM when the video was done. If that video was done at 60FPS or faster, you could have more detail, and if the flywheel was marked you'd know exactly where the noise corresponded with the position of the flywheel.

Here's a graphic to try and illustrate the idea:

I think corrosion forms under the magnets and just pushes them out ever so slightly causing interference. The new flywheel number is a revision so I’m guessing they changed with material or process to address the corrosion issue. The tricky part was after 30-40 minutes it def did cause slight misfiring too. I see a lot of guys running them with the noise thinking it doesn’t hurt but it def will damage coils over time and cause heat/running issues. I searched “rubbing flywheel magnets rough running misfire” and couldn’t find any definitive case. Well here it is…. Thanks for all the help guys!