Way too much valve clearance on intake valve

[Rockclimbnyc]

Hi Everyone,

I'm new here and I'm seeking out your wisdom. 

So I bought a 1978 Suzuki gs 750 and the engine had the top end off. I honed the jugs and the head had all new valves in it so I began to assemble the motor and when I went to check the valve clearance everything on the exhaust side is perfect and the intake side was all good except cylinder 4 which even with a 3.00 shim I still had a .013 gap. Not feeling great about this I removed the head and re seated all the valves and after putting her back together and I'm getting great on cylinder 4 and now cylinder 1 is doing what 4 did previously. I've never seen anything like this so I thought I'd ask before I wrote off this cylinder head. What do you guys think?  Warped head? Slightly bent cam? I'm open to suggestions because it's driving me nuts.

Thanks in advance! 

[wraith]

Welcome to OSS.

When you put the head back together the second time, did you put all the valves back where they came from and not mixed them up?

Could be a valve sticking, but if all are new and the head is clean?

Some one will be along to put some more ideas forward.

[Rockclimbnyc]

All the valves and springs were all bagged and labeled and reinstalled in their original locations. It's a mystery to me.

[coombehouse]

Is it possible that the valves might be bent?

If they seem ok, you could try setting the valve clearances before you fit the head. At least that way you will be able to see what is happening with the dodgy valves.

Edited March 6, 2020 by coombehouse
More info

[johnr]

were you scrupulously clean when you assembled it, it only takes a speck of dust under a shim to hold it up off its seating and assuming eveything is ok, its always good to spin the engine over a few times with a spanner on th crank before measuring the valve shim gaps just in case one of thee buckets hasnt seated right.

[BigT]

Where are you placing the cam when you measure?

Are you following the factory manual ?

[imago]

Are the collets seated correctly in the grove on the valve stem? If the collet was sitting above the grove the spring may be fully extended but the valve not meeting the seat which would make it sit low. It would still clamp to the stem because of the taper pressing inwards. Well, until you ran it up it would! 

Have a look (and take a photo) at the valve stem tops from above and see how they compare to one another.