AIRHEAD VALVE ADJUSTMENT with Pics

SurfingBob. Those all sound like symptoms of carb + valve neglect. For the shims you need. PM Dave - username "hogfiddles" - he runs a shim pool, and can hook you up. Also, you may want to post your question in the "XJ Chat" area, you will probably get better responses. thx

 

Thanks for the advice I appreciate it. I'll remember to contact Dave if I do end up needing a shim to check that properly. Once I have the shims changed and the carbs cleaned properly and re assembled and if I still run into issues I'll be sure to post any questions I have in the XJ Chat area.

 

Thanks for the write up! Just finished the process a couple of weeks ago and while I probably could've mucked through it without your expert advice, it's a huge relief to know *exactly* what I'm supposed to be doing before diving in.

 

CHecked my valve clearances today following instructions of this fantastic writeup. I ended up with all of my valves being in spec, even if barely for three of them (#2 intake at 0.11 as well as #2 and #4 exhaust at 0.16 mm).

I was amazed by the amount of oil under the cams in the lowest parts of the head. It was like little puddles of oi next to each shim. I assume that it's correct, the opposite (no oil) would be more of a concern.

The most difficult thing was to remove the ignition cover, one of the bolt head was so butchered that my electric shock screwdriver was totally useless and I had to use wisegrips to break it free.

Next, I'll have to order donuts and cover gasket to finish this job.

I also worked on my front brakes but this is another story...

 

No concern..... Sounds like a straight - up shim check.

Lots of oil - normal
A few shims barely in or even out of spec....that's why we check.

 

No concern about the shims, of course. Maybe next valve check will be more work-intensive.

I was a bit surprised that all of the eight donuts look the same, I expected to see the four inners different from the four outers, it seems that the Seca900 differs from Ftiz's bike on this point. One of the front ones has been leaking for a while, somebody probably overtighted the front ones too much to compensate, and as a result the cam chain has slightly worn out the inside of the cam cover.

 

Excellent write up Fitz. Thank you! Ill be attempting this one new to me 82 650 maxim. Would the feeler gauges sold from advance auto parts work ok for this? They're 7 bucks and seem to come with many "feelers". Or do I need gauges with .1 mm increments?

 

You're welcome.

You're better off using "pure" metric feelers such as K-D Tools' #2274 which is widely available for generally under $10. Some auto parts stores (NAPA for one) have a K-D tools display and may have them in stock. Sears too.

You can use Imperial ("American") feelers and convert but it often gets confusing.

quebecois59; if your bolts have stop collars then overtightening isn't possible. The cam chain "kissing" the cover occasionally is more likely due to it needing adjusting; or to 30 year old guides not being as "responsive" as they once were.

 

Fitz, thanks man. Had a few "ebay bucks" so I just placed my order for one.

Now hopefully I can remove my valve cover, replace the gasket and the donuts and check clearances.

Once I do that, you think my gasket will hold up so when I take it off in a week when the shims come in I wont need another 50 bucks for another gasket?

 

Fitz, one last question before I make an order with Len...

According to Len we need a special tool to turn the engine? You say a 19mm wrench will do. Home depot has those for 3 bucks and Len has a special tool for 19... I'd rather spend 3

No offense Len but money is tight and I'd rather have a wrench I'll use again vs a tool that only cranks the engine....

Its an 82 XJ650 Maxim if that matters.

 

19mm wrench works a charm. It's all ive ever used when adjusting my valves

 

Sweet, thanks again Mtn!

 

Yes. The YICS motor valve cover gaskets can be re-used many times over, as long as your "donuts" are in good shape. They're what actually press the cover against the gasket/head.

 

That's good to hear, just emailed Len for a quote. Where on earth did you get a hammer handle like that? I looked in 3 stores today and no one sells a hammer handle nor do they sell a hammer that isnt sealed so I can't even buy one and take the head off

And another newb question, how do i "clean" the mating surface without gouging the block? I know it has to be spotless for the gasket to sit properly...

Thanks a million for your help, looking forward to doing this soon!

 

go in to a real old school hardware store.... not Lowes or Home Depot, or sears..... go in to your local down home hardware store... they will have wood hammer handles

 

Will do that on lunch today. There is an old school hardware store near my work.

I bought a torque wrench a while ago, it was 15 bucks and I don't trust it fully. What does 8 lb of torque feel like if just using a hex bit and my socket wrench? Would hate to overtighten and ruin the donuts i just paid 40 bucks for!

 

Oh you won't ruin the donuts; the bolts have stop collars and if overtightened you'll strip out the holes in the head.

Since you can't GET TO the inner ones easily with a hex bit, use a long 5mm allen wrench. About as much torque as you can put by hand on a standard allen wrench is about it. Then just use that on the outer ones too. "Just tight" is all you're after.

 

Don't use the Socket Ratchet Handle.

Use a Long Allen Wrench.
7.5 ~ 8.0 FtLbs is roughly equal to "Pinky-finger Tight"

Just the Pinky.

 

Right on, I'll use the socket handle to get them off, but I'll pinky tighten the rest to get into the correct torque range. Thanks guys

 

Fitz do you use any sort of sealant on the half moons? That's where I'm leaking from nwo and would like to NOT leak from there when I get a new gasket