AIRHEAD VALVE ADJUSTMENT with Pics

I use "Indian Head Gasket Shellac"
It's messy stuff.
But, its a great Sealant with adhesive properties.

 

WHAT BIKE? Pleeeese put it in your sig so I don't have to go look it up.

Pre-YICS: the "half-moons" are separate from the gasket itself and I haven't replaced mine yet (my 650 is still a slow WIP.) I would say no on initial use (silicone or other grease) and maybe on re-use.

YICS rubber gasket: I put a tiny dab of RTV in the sharp corners where the half moons meet the head; but only on the subsequent re-uses of the gasket. The first time, it just gets "greased" (silicone lube or whatever grease is handy) on the head-side. I "glue" the gasket to the cover as outlined in this article.

 

Thanks fitz. Its a YICS engine. A 1982 XJ650 Maxim. I'll add that to my sig shortly.

 

Does the engine have to be stone cold when doing valve checks? I have to ride it 15 miles to work and use the warehouse to do my work.

If it has to be stone cold, I may just do the valve cover after it cools off for an hour or so. Then come back on Sunday morning to do the valve clearances.

 

YES..it must be COLD. As in "STONE COLD", or "OVERNIGHT COLD". If you've run it AT ALL, your measurements will be off.

If you're gonna do it at the warehouse, ride it over and park it. Wait til the next day to do the work. No point in waiting an hour to pull the cover. That'll only take you a few minutes to pull off anyway. You'll waste an hour waiting for a 5 minute job.

Dave F

 

Dave,

Well I wanted to put a new gasket and "donuts" on the cover... Figured I could at least do that much on Saturday, then all I have to do is valve clearances on Sunday Or is that a stupid idea?

Figured removing those donuts from all those bolts will take some time... cleaning the valve cover and putting a new gasket may take some time too...

 

What Dave is trying to tell you is that the bike WILL NOT cool down enough in an hour to give you accurate valve clearance readings.

He's right. It won't.

Go ahead and pop the cover; then lay a couple of shop rags across the top of the motor so nothing falls in there, and do yo' 'ting. Come back in the morning and check the clearances when the motor is truly cold.

No need to reinstall the cover, it can sit overnight "open" as long as it's covered up. I usually end up having to do that, for various reasons.

 

thanks Fitz. Im doing the donuts right now. 45 minutes and still don't have a single one off yet. Any help would be greatly appreciated as I'm running out of valuable time right now!

 

So there I was trying to cut metal. Nope, just bend the metal with a diagonal cutter, then cut away the rubber, the screw will just slide out of the metal washer. Phew, that was rough but it's done!

 

2 of my intake valves are at .11. Should I size them down just to be safe? They'll probably be too tight within a thousand miles I'd assume if they're right on the cusp.

let me know while I've got the valve cover off!

 

Personally I would go down a shim. It'd bring you to .16 which is .01 over. But better than being too tight IMO. Plus you have the cover off so mine as well do it now than wondering how long you have to wait to check it again.

 

Fitz has said it before and others as well. When it comes to the shims you are 100% in or 100% out of spec. If your intakes are showing .11 and you are using metric only gauges so you are 100% positive that you are at .11, Leave them in there. remember in about 5000 miles you are gonna have to check your clearances again. So if they are too tight then, then replace.

 

Steber and Osprey, 2 competing comments! I dunno what to do now!

I checked the shims in every valve.

I'll post the results later. I dunno if I should drop a size on the .11 valves...

 

What shim is in there now? Will one of your spares once shims are replaced be a step down in shim size? My suggestion would be put the next smallest shim in there, remeasure and see if it falls in spec. You never know, you may have had too much drag when you measured today and find that the smaller shim gives you .15. That or order the shim you need and do the same. If it puts you out of spec throw the old one back in there. I'd personally feel alot better with being on the looser end than the tighter end. If it turns out you don't need the shim hold on to it and 5,000 miles down the road you'll probably need it.

 

OK here are my results

Intake: clearance/shim installed
1- .10 (280)
2- .08 (280)
3- .11 (275)
4 - .11 (265)

Exhaust

1 - .17
2- .14
3- .18
4- .14

So I think this is what I need

Intake:

1. 275
2. 275
3. Spec
4. Spec

Exhaust:

1. Spec
2. 265
3. Spec
4. 265

Am I correct here?

 

You are correct.

 

You forgot to post the exhaust shims

 

Oh yea damn. I forgot the paper at work too.

Ill post tomorrow

 

I remember actually. All my exhaust shims were 270

 

Please discuss this in YOUR thread; this is now 14 pages long.

Thx--- Fitz