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Discussion Starter #1
Just adjusted the tappets on 1986 JDM spec 750 but have found that the procedure in the manual (see pics) doesn’t quite work.

When it says adjust number 1 for example, the cam slots are facing outwards and the “T” aligned on the rotor as per the manual, both number 1 cam lobes are pointing out towards the outside of the casing. If I rotate the crank I find that the gap is bigger on the exhaust when the cam lobe is pointing up, hence adjusting it when directed would mean the clearance is tight..?

This is also true for number 3 exhaust - the cam is up when it suggests adjusting it, but the gap gets bigger when it’s facing the outer casing, and 4 exhaust it says adjust when facing the casing but the gap is bigger when the cam is facing up.

This is only true of exhausts 1, 3, and 4, number 2 is basically the same gap forward and up.

I tried this 3 or 4 times as I wondered if I was going mad. The cam is worn, you can see slight ware on the lobes but I’ve decided to run it and sort it out later.

Has anyone else found this, does this point to wear on the cam, journal or head..?

I think I’m right is adjusting the clearance at the widest point, it’s just that I’m bothered it doesn’t match what the manual says...

Help...

576136
 

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Likes to race old junk.
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I just rotate the crank, until the desired cam lobe is facing straight up...so that's base circle, zero lift at that point...that's when you adjust the valve clearance.
The manual's instructions will let you perform the valve set with the least amount of cranking, do it or don't...just keep track of which cylinders you've done, torqued etc. You can turn it over 16 times, if that's your preference.

Most people overthink this.
Valve clearances are a range...too much is bad, too little is more bad.
Using a dial indicator is far more accurate than feeler blades...does it really matter, as long as we fall some where within that range?

If your cams are worn to the point, that the wear is beyond the lobe's surface hardness...then the rocker pads usually aren't too far behind.
 

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Discussion Starter #3
Agree, that’s what I usually do, and that makes sense, BUT how the hell can the clearance be more when the cam lobe is facing the front of the bike, I.e 90 degrees on from fully up...? It’s definitely the case, I’ve been thinking about it, it can only mean wear the hence unevenness ... hey ho...
chz for the reply
 
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