YTM Top End Noise

[_brad_]

Alright, well I bought my first 3 wheeler a while back and I have always noticed a evident tapping noise coming from the top end. The noise is evident at idle though all throttle ranges; with getting loader at higher RPM. It does not appear to cause any performance loss or anything of that nature... I took it for its first "real" all day ride where I burned a tank of gas and it performed great.

I'm just wondering where this sound is coming from... I was thinking maybe a valve adjustment would be needed? :wondering Or worst case maybe a stretched cam chain? :wondering

Any thoughts would be great. I'm just wondering if its worth tearing apart the motor or not...

[HEAD09]

check the rocker arms for adjustment...

[pickleweasel_00]

and i think the tension on the timing chain can be adjusted

[_brad_]

OK I need YTM pros here.

Doing a complete strip down of my 1984 Yamaha 200L.

So, I performed a valve adjustment on my YTM200L. Upon performing a valve adjustment according to the specifications of the manual;

"The clearance is intake = .05-.09 mm (.002-.004 in), exhaust = .11-.15 mm (.0043-.006 in)."

So the first time around I set intake at .075 mm (dead center in between recommended specs) and .13 mm on th exhaust side (also dead center in between recommended specs). Start it up, same tapping noise from top end. Took covers off again and the second time around I set the valve clearance to the absolute minimal specified in the manual; .05 mm for intake and .11 mm for exhaust.

Start it up and same thing. At this point I had pin pointed the top end noise to the intake valve rocker arm. It STILL just seems like there is too much space between the rocker arm and top of valve!! This is what is causing this tapping noise on top end.

SOOO I need other YTM owners!!! Do any of you have a tapping noise coming from intake rocker arm area on top end after performing a valve adjustment according to the Clymer manual??? If so, I will just ignore this sounds and move on. Its just annoying. I just think that despite what the manual says it seems like the intake valve clearance should be smaller to sound down the rocker arm tapping noise... I mean, .05 mm is a pretty big gap dont ya think?

I dont know. I have always stuck on the strong side of always following the manual. This time it just seems whack! I know I could shut up this rocker arm noise by going in a little bit more on the intake rocker arm but I dont want to burn up any valves either! :eek:

Secondly, I have adjusted the cam chain at the same time. Problem is, the Clymer manual is very vague on EXACTLY HOW MUCH MOVEMENT "SLIGHTLY" IS. I mean, it basically says that the pin should "move slightly" how in the hell much is "slightly"? I mean one persons version of "slightly" will not be the same as anothers... Ya know? So my question is, how much would you guys think "slightly" is in accordance to the cam pin movement during adjustment? I mean the pin seems to always have a slight move to it even on its tightest position... But you can hear the wear on the cam chain guides when its 100 % tight so I know the chain and guides still have some wear left... I just backed it out until it started to really wiggle back and forth...

Any help would be great!

[WIkid500]

Here is your other YTM owner with ticking noises from the top end. It's common. Mine ticks when it's hot. I adjusted the cam chain as per spec in the book, then I adjusted the valves as per the book to the tight side, and it still ticks. The problem is the rockers, and the cross shafts get worn, and I assume the cam lobes too, then things start to tick.

When I change oil in it I don't find much for metal in the filter so I don't care that it rattles any more. I used to freak out about the noise, but after this winters abuse I don't think it will be a problem. We rode hard on the ice this winter, 4 hours at a time wide open around the lake shifting gears and hammer down. I constantly have my thumb to the peg on this thing, and it's holding together so don't worry about it.


Ride it like you stole it and worry about it later.

[filipinoredneck]

I just did a top end rebuild on mine and it also ticks. I think i'll wait for the clunk and the boom before I worry any futher.LOL:lol: She's running strong and that's all I care for right now. I got three other trikes on the go.:beer

[burnoutboy]

The YTM's are prone to developing a flat spot on the rocker arms. Nothing to worry about.

[_brad_]

Would it be feasible to shorten up that space between the rocker arm BELOW the specs of the manual to sound the noise down?

Or would that just be stupid? I guess I'm more leaning towards ignoring it. What about the cam chain? How much is "slight movement"? Any thoughts?

All these replies are great! Thanks everyone!