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Just to be clear, I would want to get the clearance to .11mm and not .08mm? You'd want it bigger because over time, the gap closes?

Awesome advice, thanks!
That’s correct. For example, the exhaust clearance spec on my R6 is .23 - .30mm, so when I have to adjust them, I shoot for as close to .30 as I can with out going over. Look at your own results. The only ones that have moved off of .0889 are smaller, right? This are the ones that have moved. The gaps have closed up, not gotten larger. This is because the wear method is not friction wearing down the cams or shim buckets. It is the valve base trying to beat its way into the valve seat hundreds of times each second. As it beats it’s way into the valve seat, the stem gets closer and closer to the cam lobe.
 
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The nice thing is that it appears your bike is "shim over Bucket" so you don't have to remove the cams to perform the valve adjustment. You will need a tool like the one in the link to push down on the shim bucket and remove the shim. But here is a warning.... DO NOT ROTATE THE ENGINE WITH ANY SHIMS REMOVED!!!! You will end up scoring cam lobes and/or getting metal grind filings in your engine. On my GS, the shims are about the size of a quarter, so when I remove a shim, I insert a coin in its place as a fill in. That way I can remove more than one shim at a time and replace them or swap them around.

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Any recommendations on where to get shims?
Z1enterprises, 4into1, BikeBandit.... any online store that has them in stock.

First you need to figure out how many and what sizes you need. Then decide if it is better to buy a few individual shims, or an assortment kit.

The other option that I’ve used is to make nice with a mechanic at a local shop and see if he’ll swap a few shims out with you. They always have a stash of shims in a drawer somewhere.
 

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CB750 DOHC is probably better motor than the 900 as it's a shorter stroke motor. Saying that, they do have multiple issues.
Exhaust valves tighten up due to seat/valve face wear but intakes can stay in spec for 20,000 miles (after yje first 10,000 have been done)
Primary chains seem to wear much faster than 900, probably due to owners 'wanting' a 900 but for various reasons (usually financial) getting a 750
Biggest issue I saw with the 750 and 900, the front cam chain guide wears and /or breaks allowing loose chain to contact front of cylinder then 'sawing' a slot through it. Usually caused by not having dealer service motor and only adjusting the 'easy' (front) tensioner and ignoring the one underneath carbs.
The alloy is pretty poor quality so welding 'slot' was pretty hit or miss and usually still leaked some oil.
The only other 'fault' was the ignition units (the little silver 'block' not CDI) overheating and melting but they are easily swapped for GM units
 

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Discussion Starter · #48 ·
CB750 DOHC is probably better motor than the 900 as it's a shorter stroke motor. Saying that, they do have multiple issues.
Exhaust valves tighten up due to seat/valve face wear but intakes can stay in spec for 20,000 miles (after yje first 10,000 have been done)
Primary chains seem to wear much faster than 900, probably due to owners 'wanting' a 900 but for various reasons (usually financial) getting a 750
Biggest issue I saw with the 750 and 900, the front cam chain guide wears and /or breaks allowing loose chain to contact front of cylinder then 'sawing' a slot through it. Usually caused by not having dealer service motor and only adjusting the 'easy' (front) tensioner and ignoring the one underneath carbs.
The alloy is pretty poor quality so welding 'slot' was pretty hit or miss and usually still leaked some oil.
The only other 'fault' was the ignition units (the little silver 'block' not CDI) overheating and melting but they are easily swapped for GM units
I plan to eventually upgrade/update all of the electronics and wiring. I was able to check the condition of the two tensioners and seem to be in pretty good. The valve seating us within spec when I did the measurements. So overall the motor is in alright condition.
 
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