Should I tear into my engine?

[smiles79]

Hi all,

Some of you may have seen an earlier post of mine about some top end noise I've been noticing on my '75. Here's a video:

I replaced my tappets (stock ones were pitting pretty bad), checked cam chain tension, and set my valves (.002" on the intake and .004" on the exhaust). Unfortunately, I'm still hearing the noise. Should I tear into the engine? I think it'd be fun and interesting, but I'm not sure if it's necessary or not.

If you 650 masters think I should, what are some things I should check, regarding the top end noise as well as just general maintenance and things to look out for?

Let me know!

Thanks,
Smiles

 

[XSLeo]

The XS650 doesn't have tappets. It has rocker arms. They ride on the cam on one end, the valve stem on the other. They have adjuster screws in the valve end for clearance adjustment. You have your clearances a bit tight. .003 I, .006 E is better. To tight they might not seal as they should.
Leo

 

[smiles79]

I guess I've just always heard them called tappets, but yeah the adjuster screws is what I was talking about.

As for the clearances, I just went off the Clymer manual.

 

[deadchef]

i dunno, if you've set everything correctly, oil is pumping and you aren't fouling plugs, i say run it. if you feel inclined to do a top end rebuild, do it over the winter.... or after she blows! lol

 

[smiles79]

How does one know if oil is pumping to the top end correctly?

 

[5twins]

Have you tried setting the cam chain tension while the motor is idling? It's the easiest and most fool-proof way to get it set right. If it's too loose now, that could be the source of the ticking.

 

[smiles79]

I haven't. Will it make a mess?

 

[angus67]

Take off the left side intake rocker cover, and start it. There will be some misting of oil if pumping oil, or loosen the oil delivery pipe on top of the head and start it. Just loosen them, it will make a mess.

 

[5twins]

Setting/checking the cam chain while the engine idles doesn't make a mess. A little oil may ooze out resulting in a couple drips but just fold up a paper towel and set it on top of the engine case under the adjuster. That will catch the couple (if any) drips that might occur. The oil doesn't squirt or shoot out all over the place.

Observe the plunger in the end of the adjuster as the motor is idling. It should pulse or bounce in and out about a MM or 2. If it's bouncing in and out more, the adjustment is too loose. If it doesn't move at all, your adjustment is too tight. If you're set too loose, as you tighten the adjuster up and take out the slack, the ticking will go away.