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Discussion Starter · #1 ·
Here’s the story:

Did a valve job. Fired her up and had a lot of tapping noise. Asked my neighbor if he thought it was normal. He’s an old timer. He gave me the okay then I look down and for some reason there’s a 875 shim in my toolbox. Somehow when using a magnet to hold the rocker arm in place to get its pin back in it picked up the exhaust shim and I never knew I was rocking only 3 shims in the motor. So I go to put it back in hurriedly and confused and drop it down the cam chain. I bought a new right side crank case cover to fix my weep hole oil leak and take the cover off. Can’t find the shim anywhere. I take the other shim out and drop it down the same spot to see it drop all the way through to get an idea of how they’re bouncing and where it could be. Here’s the problem: it never made it to the bottom of the cam chain. I’ve got four shims lost in this bad boy now. I’ve tried shaking, even turning the motor like a jackass. The shims are nowhere to be found. What on the cam chain side could stop a shim from getting to the bottom? They could magnetize to the chain itself but then I’d be able to see it plain as day. I look in and there’s nothing like they’ve disappeared. Bought a **** air compressor and no matter how much I shoot around in there and how much prodding I do with a magnet I can’t find nothing.
Any ideas to where it could be? My 250 is my typical daily transportation I’d like to get her buttoned up asap.
 

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More fishing around with a strong magnet on a rod seems like the first thing to try.

Next might be pulling the engine cover on that side (can't tell if you've done that or not).
 

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Discussion Starter · #3 ·
Clutch side cover is off as well as the valve cover, trouble is I have visual access to just about everywhere it could be but they’re nowhere. If they could have gotten under the chain somehow when rotating the motor it would have worked itself down and out but that never happened. I don’t think taking the alternator cover would be helpful at all since it went down the timing chain?
 

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Discussion Starter · #5 ·
I’ve rummaged around there with a magnet and haven’t gotten them. When I shake the bike I don’t hear them clanking around there which I should since it’s absent of all oil/coolant now. Really the issue is when I physically dropped the other ones down the chain to look at what they would hit from the removed side case they never made it to the bottom of the chain/the side case area. They’re somehow getting stuck higher up. Maybe I could put the bike on a fork stand only and the cylinder would be more vertical instead of tilted forward which could maybe have them lodged somewhere? Not a lot of space the bike is now in my kitchen since a snow storm came and the internals are all exposed.
 

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Could be stuck at cam-chain tensioner?

Use borescope camera to go down and look. Really helps to be able to see sideways and back up.

 

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Discussion Starter · #8 ·
Could be stuck at cam-chain tensioner?

Use borescope camera to go down and look. Really helps to be able to see sideways and back up.

I’m going to buy one of those right now.

pics:

Tire Wheel Automotive tire Crankset Vehicle

finger pointing to where I dropped them.

Tire Wheel Fuel tank Vehicle Automotive lighting

Case cover is off. They’re not making it to the bottom of the chain you can see just next to the clutch. I have a new case cover to go on to fix my weep hole oil leak. Bike has 35k on it it’s my daily to work 100+ miles per day and I got racetech/ohlins on it I bought a trailer and was hoping to start tracking it next year.
 

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I like Danno's borescope idea.

Odd for sure - but they are in there somewhere!

I dropped a feeler gauge down an engine when doing the valves back in the day. Now I pack rags in any openings if I'm working with a single feeler gauge or shim.
 

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I like Danno's borescope idea.

Odd for sure - but they are in there somewhere!

I dropped a feeler gauge down an engine when doing the valves back in the day. Now I pack rags in any openings if I'm working with a single feeler gauge or shim.
I almost did something similar, the nut holding together a pack of feeler gauges came off while I was holding it over the engine of an S2000. Luckily it missed the engine and bounced elsewhere, I made a lucky guess and found it in a few minutes under a tool chest. Maybe I like to like dangerously, as I still don't use rags, but I did locktite that nut in place!

Another +1 for the borescope. Its not magical, but pretty close. I found my 250's dipstick o-ring after it got forced inside, and after draining the oil. Many times its also helped locate sockets I dropped into car engine bays.
 

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Discussion Starter · #12 ·
Even with Amazon prime the scope won’t be here until Sunday. I don’t think poking around in there with a magnet is much good use of my time anymore so I’ll probably just take a break until then. If that doesn’t work, I know a lot of guys have success flipping dirt bikes upside down. For me it’ll probably be way easier to just take the motor out then to try and flip over a 350lbs bike and not damage anything. I guess I’ll keep everyone posted on how the next step works out.
 

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It's very possible they went down towards inside like jkv said and is in crankcase. To help follow path, drain all oil and spray carb-cleaner down there to make it easier for camera to see.
 

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Discussion Starter · #14 ·
Shipping has been delayed on the camera. I’ve managed to get 3 of the 4 shims out. They were as I expected trapped under the chain. I was able to push on the chain guide at the bottom to barely get enough room to grab them with a magnet. It seems like the final shim isn’t under there.
 

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Shipping has been delayed on the camera. I’ve managed to get 3 of the 4 shims out. They were as I expected trapped under the chain. I was able to push on the chain guide at the bottom to barely get enough room to grab them with a magnet. It seems like the final shim isn’t under there.
3 out of 4 ain't bad!

What did you use to get them out?
 

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Discussion Starter · #16 ·
3 out of 4 ain't bad!

What did you use to get them out?
I pushed on the chain guide with the end of a long extension and wedged a popsicle stick in it then wiggled it around to get them to come all the way to the bottom then made more room with the extension and caught them with a magnet. When I finish work today I’m going to strain the oil I drained I have a feeling the original lost shim may have drained out. If it’s not in there hopefully that camera will show up eventually and get put to use.
 

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Discussion Starter · #18 ·
Well the saga has ended. The camera never showed up, but when I went to strain my oil pan I immediately found it sitting in a pool of oil. Most likely what happened was the original shim made its way to the sump and was drained out then I purposefully dropped the other 3 behind the chain looking to see where the first had gone.

advice for putting the shims in: use a magnet to take them out AND put them in. You can line it up on the bucket then use a long thin tool to hold it on the bucket so you can pull your magnet off. This way you won’t drop it in there like everyone does with tweezers. Boy this was fun.
 

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Well the saga has ended. The camera never showed up, but when I went to strain my oil pan I immediately found it sitting in a pool of oil. Most likely what happened was the original shim made its way to the sump and was drained out then I purposefully dropped the other 3 behind the chain looking to see where the first had gone.

advice for putting the shims in: use a magnet to take them out AND put them in. You can line it up on the bucket then use a long thin tool to hold it on the bucket so you can pull your magnet off. This way you won’t drop it in there like everyone does with tweezers. Boy this was fun.
I had JUST purchased a extendable magnetic tool from harbor freight the other day thinking, "I might need this." Paid for itself when I did my tear down. I couldn't imagine using anything I had to remove or install those shims after that. Glad you figured it out! Amazon makes returns easy :)
 
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