AIRHEAD VALVE ADJUSTMENT with Pics

My god,this motorcycle looks so new like it was bought yesterdays.Its like it came from an exhibition show!!!! 8O 8O 8O

 

i checked my clearances today to find i need 3 shims. out of curiosity, when i was done, i checked the clearance all the way around the bottom of the cam lobe, and found that as a rotated the engine ccw, when the cam lobe was about 90 degrees PAST straight up from the bucket, pointing in a line parallel to the shim, i measured more clearance then when the cam lobe was straight up. is this normal?

 

Yes; well, sorta. The cams are kind of erratically cast, and only "precise" in those areas where they NEED to be.

Check the clearances where the book says to; with the cam pointing straight up away from the face of the shim.

 

got it. thanks!

 

Bigfitz,

Thanks a lot for posting the pictures and instructions. I will get to this since the engine that is going on my XJ is not mounted yet. It is great to find out this "How to" threads with lots of pictures for us newbies on how to work on a bike.

This is one thing that I will do to the engine that is sitting in the shed waiting to go into the bike.

 

Great write up. This makes it seem so much less daunting.

 

I die a little inside everytime I see pics of Fitz's bikes....I could only dream to have mine that clean. I would LOVE to see a video of it running!! Don't suppose you got one huh Fitz?

 

The best of it is, the thing's his DAILY RIDER! 8O :lol:

 

He uses a special product to keep it that way. It's called elbow grease

 

Hi. I have owned my XJ550 for about 5 years now. The bike itself was running at the time but poorly and it has gotten to the point where I am today and that it doesn't run at all. The previous owner kept the exterior in great shape but the more I used it the more I discovered it was never properly maintained. Initially I thought dirty carb was the problem so I cleaned it a few times and it seemed like it wasn't helping. I remember BigFitz mentioning that carb cleaning is pointless without checking the valve shims so that's what I decided to check next. Thanks to this writeup I have discovered that I am in the same spot crewwolfy was way back on page 4. They all are out of spec measuring 0.102mm and one which is also not even measurable so I'll need to see if the other valves have smaller shims I can swap. I am looking forward to ordering the new shims and seeing what results this will give so I can get this bike back on the road. Out of curiosity, if it wasn't already mentioned, would the consequences of having the valves out of spec cause my bike to flood at high rpms and just bog down if revved up? And also be the cause of starting issues? It seems like if I could get it to start and idle it was sort of fine as long as the choke was on and it ran but forget about accelerating too fast it would just bog and almost stall going up small inclines.

Thanks!
Raymond

 

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

 

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