Ytm 200 ticking

[Mike33]

So, I have recently bought a 1983 YTM 200k. When I have it running, I hear a semi-loud ticking noise. I had a mechanic friend take a quick look when he was over and looked at everything. He tightened the valves and also loosened the valves but no luck. He also checked the cam chain tightness and it being centered but also not luck. He says he still thinks it has something to do with the valves though, but doesn't know what. What could it be? Could the decompression arm be causing it somehow? I have noticed it has very little play compared to my honda. Are yamahas different?

[ATC King]

Check the intake valve inspection cover, to make certain it's not on upside down. It will go on either way.


It has a shallow and deep side, and a little arrow like protrusion on the inside. That protrusion should be at the top.

If it's on upside-down, there's a little bit sticking off of the valve lifter that can just contact it and make a ticking noise.

[Mike33]

Checked that, doesn't change the sound.

[El Camexican]

Take a piece of wood dowel and use it like a stethoscope to find the source.

Are your oil filter and oil strainer clean? Are you using the recommended oil weight? Does it tick all the time, or just when it’s hot?

[thefox]

Sometimes when the YTM top end is starved for oil it wears the rocker arm lobes. Pull the cam chain tensioner, cam chain sprocket, and cam. You can look in and see the rocker arms, they should be convexed without flat spots.


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[Mike33]

I adjusted the valves, cam chain tensioner, and checked the intake cover. Still making the loud ticking noise. More bad news is that when I changed the oil and oil filter, there was quite a few metal shavings and some were larger than I would like.

[El Camexican]

The primary clutch in that engine sheds metal by natural. Most of the shavings that stick to a magnet come from the housing and the ones that don’t probably come from your secondary clutch basket. A 1/4 teaspoon of shavings per oil change on that engine is not abnormal. Just make sure your secondary clutch is properly adjusted to avoid adding transmission gear chips to the pile.

Tore a YTM head apart on the weekend. Perfect condition with the exception of a worn intake rocker shaft. That might be the source of your tick. Can be removed for inspection fairly easily.