AIRHEAD VALVE ADJUSTMENT with Pics

I have a 1982 XJ650 with a 5N8 engine. It never ran good at all. I could never turn the choke off. I had a guy across the street perform a compression check with a Mac Tools compression checker. He said Harbor Freight testers are junk. From left to right 150 140 140 140. So it's getting great compression. So what does tight valves have to do with the piece of junk not starting? The valves have to seal to get the compression so what's the deal? I am getting brilliant spark, compression and I know the backwards petcock is working because the only way fuel flows from the tank is when it's on PRI. I seen this in another post about those worthless hitachi carbs. It stated they cause the most problem of the bike. Do they still make those carbs? Because I am going to destroy them. They need to be put out of business. I also noticed the more fuel in the tank the easier it is to start. I am at a lost. I am in my 40's and I have NEVER NEVER NEVER seen a bigger piece of junk as the Yamaha XJ650 is. I think Yamaha should be told by the government to stop making motorcycles as they have no clue how to make them. They should just make musical items as that's what they started the company for. I can't even ride the bike on the roads because it's not inspected. Just because Yamaha couldn't use the standard 17 digit vin. Is there not another kind of carb to use on this bike? You can't tell me that someone hasn't put something else on the bike.

 

This rant about your inability to cope with your 31 year old motorcycle doesn't belong here.

Please start a new thread if you want advice; then take the advice given.

 

Just froze doing this. These are the readings I got. Ex 1 .004 In 1 .004, In. # 2 .004 Ex. 2 .005 or .006. In #3 .003 Ex #3 .005 In #4 .0015 Ex. .005 or .006. I just don't understand how you can have great compression but if your valves are a hair off it won't start. When you look at the difference between .002 and .0015 it's like a piece of paper. I have another engine is there a section on removing a engine?

 

Think about how much room, and velocity, a volume of anything needs in order to fill up a space efficiently. Then adjust your valves. Swapping the engine isn't the correct course of action. A difference of a hairs-breath in thickness is all that's needed to change the flow characteristics of a valve once it's out of adjustment.

 

First off, get some metric feelers, because .004" is actually closer to .10mm than it is to .11mm, which is spec. K-D Tools' pn 2274 is widely available for around $8.

Next, you don't replace the motor because your valves need adjusting. You adjust the valves. Follow the instructions carefully (or read Part Deux if you don't want to invest in the tool) and "read" the shims on the tight valves then order replacements. Replace the shims on the tight ones with shims the next size (or two sizes) smaller as needed to bring them into spec. Once you know what shims are installed, we can help you figure out what shims you need if the process is unclear.

This is XJ engine maintenance STEP #1 in all of the books. Not a reason to replace the motor. (Ya gotta do it every 5000 miles.)

 

New to the site, so hello all. Fitz, this was something I was going to have someone do for me, but this write up is fantastic! Making things a lot easier for a lot of people. I appreciate the time you put in this one for sure!

 

You're more than welcome. If you plan to keep and ride the bike, having somebody do it for you every 5000 miles can get expensive. So it really does pay to learn how to do it yourself. Keep a log book with what shims you install and the clearances, date and mileage. It will make the process easier next time. Once you "monitor" the valves, you can pretty much predict which ones might go out of spec by the next adjustment, and have those shims at the ready making it a one-step process.

 

Man this is gold!!!!

 

Thanks!

You might also appreciate Part Deux: http://xjbikes.com/Forums/viewtopic/t=29209.html

 

Ok I dont get it. I am almost ready to do this. How do I know wich shims to get before disassembling it? I only have the cash for one gasket these things cost 0ver 70 dollars. Is it possible to buy a ful set of shims then resell what i do not use? Also can I get the shims out witute using that custom tool? I am doing this in a 8 hour time window in my carport so I can only disassemble once. I plan on buying the gasket and donuts when I get my taxes.

 

get the gasket and donuts, have them ready. You CAN'T know the shims unless either you or someone else did them before and wrote down what sizes went in.

You HAVE to pull each shim to see what size is stamped on the underside of it. It's on the underside so the cam doesn't wear it right off.

First you check the current clearance, then you pull the shim and check the number, and put the shim back in. Then you do your math and check the chart to determine the correct shim. Do that for all of them. Then you figure out what can swap around, and what few shims you need to get. Then contact me for the shim pool, or buy new from Len. Either way, an hour and you'll know what you need. Then when the shims arrive, swap them out, put on the new gasket and donuts.

You do NOT have to use 'the tool'. You can use zipties. That's my preferred way, and I have TWO of 'the tools'.

If you need help and want to be walked through it, start a conversation with me and I"ll help you through.

Dave Fox

 

thanks dude. I will let you know. I am also considering letting my local shop just handle it. Still haven't decided yet. Basically I will be going out of town at the end of March and may be putting the bike in for shock seal replacement. may have them to valves too while they have it for that week and save me the aggravation of a rushed carport surgery.

 

I bet they don't know what to do. At least make sure you get a sheet showing:
What the original shims were
what the clearances were
what the new shims are

That way you can correct it.

 

I asked a local shop how much for a valve adjustment, the answer was $300! I ended up doing them myself. fortunately for me, I had prior experience with the late '70s water cooled Volkswagens (rabbit, scirocco) from my auto repair days.

FU

 

what shim set on amazon do I purchase? As far as the shop goes they are a very professional shop.http://www.hudsonmotorcycles.net/default.asp very professional and knowledgeable.

 

your way over thinking this pal, take your measurements, read the sizes on the ones you need, put it back together with the ones that's in it now use the old gasket for awhile, when you get all your stuff, change them.
if you read all the shims, maybe you only need one or two, why buy a whole kit.

 

If you'd rather spend a couple hundred buck for a whole shim kit, that's totally up to you. ME?.......I'd rather just swap out the few shims I'll need for only a few $, but do what you want. Who am I to tell you to save your hard-earned money for something else that you might need it for?

dave

 

I will attempt the measure-close-order shim-re-open and replace method. Because yeah, I do not want to buy a whole shim set either. I found this on ebay http://www.ebay.com/itm/Yamaha-XJ-7...pt=UK_Motorcycle_Parts_13&hash=item53fcb537d2 I may get two for good measure. Just need to find the donuts too

 

Chacal has all the parts you'll need. Start a conversation with him. You don't need to order parts from the uk.

 

Get you parts from Chacal.
Have the gasket in hand prior to doing your first measurement / shim thickness documentation.
Chances are really good that when you remove the cover that your existing gasket will not cooperate.
Do not fret!
Mine was a mess - meticulously clean the gasket material from the engine and cover (make sure no debris falls in the engine). Put a thin bead of gasket sealer on the cover side of the gasket and a light film of oil on the engine side.
I have been able to remove my cover multiple times since doing this without damaging the new gasket.

 

Thanks Stump that makes sense about the new gasket. I have put my part list together and am anxiously awating my taxes.

 

ordered my gasket and bolts and stuff from chacal! Recieved my feeler gauges my hex sockets my oil filter...just waiting for the gasket and a new oil filter screw thing.. then i will begin my operation. Received shim tool.

 

Sunday. Sunday. Sunday!

 

Don't forget the torque wrench. Those bolts don't go on very tight. And they snap off very easily and a pos to get out if ones breaks. Trust me.

 

I got one for Xmas. http://www.amazon.com/gp/product/B000MB53ZE/ref=oh_aui_search_detailpage?ie=UTF8&psc=1. That is why I picked up the hex sockets. I have tons of allen wrenches.

 

What do you do when all of your buckets are turned and you cant get into the groove to pop the shim out?

 

You use a small screwdriver or your fingers to turn the bucket around.

 

I tried to spin it with the tool in place and it wouldnt budge. Is there a specific position the cam needs to be in to rotate the bucket?

 

you CAN'T spin it with the tool in place.....It's wedged in place with the valve spring and the tool! BEFORE you put the tool on, or the ziptie in.....when the cam is rotated away from the shim, you can EASILY rotate the bucket. BUT....make sure that you hold the bucket in place as you rotate the cam again, or it will spin the bucket out of reach again. If you're going to use the tool....rotate the cam a few times and watch just how far the bucket rotates. You'll get a feel for where to index it so that the cam rotates it right to where you want it.

NOW....all that being said-- if you go with the ziptie method instead, you can rotate the bucket all day long since the valve is held open from inside the cyl rather than by holding the bucket down.

You don't need a torque wrench for the valve cover bolts....they have a shoulder on them. run them down til they stop, then give them just a tweak and you'll be all set.

Dave F

 

Sorry if this is a silly question, but I have pools of oil in the low points which covers the lower lip of the bucket where the tool goes and makes it hard to see. Any tricks for draining this oil? (see pic below)



Thanks!

 

absorb it out with a clean paper towel or similar. also cover the cam lobe with a towel when removing the tool, sometimes the shim will pop in and squirt oil some distance, and somehow find it's way into your eye. no kidding!

FU

 

Thanks! I figured it was something simple like that. And good tip. I've already had a little oil squirt up.

 

Yeah just absorb it.... It's not hurting anything there though

 

If the oil has been neglected in the past there may be sludge there. Never a bad idea to clean up while your in there , but just remember that you will have to add a few ounces of oil after you run it

 

Question?
For the high tack gasket sealer does anyone have a tried and true brand they've used?
Would rather go into it with the proper tools.
Thanks,
-EM

 

Permatex. It is commonly available, and works as well as any.

 

I got a problem.
I've tried to follow your instructions, but I can only rotate the crankshaft (once) to the "F-mark" on the timing plate... Then it stops.
What to do then?

 

Start at thread of your own. You have problems that need to be looked into thoroughly.

 

Before I crack this thing open is there still a shim pool going on?

 

Yep.... Once you know what sizes you need, let me know and I'll see what I have. Also, if you are unsure of your calculations, run the numbers past me and I'll check them for you----

Dave fox

 

Dave, thanks. Might not be till just before Christmas.

Thanks again!

 

Whatever/whenever

 

Sorry , I had too.

 

I just found out what not to do.
I had a valve job done. Before that, I popped out all of the shims and recorded. Got the head back, reassembled, and checked clearances. Everything was tight as expected. Using the chart, I found out what size shims I would need to get into spec. I noticed that the 270 shim in intake 1 could be used in intake 3. By moving 3 shims around, I only needed 5. I used the insulated #12 wire, popped out the shim in intake 1. I then rotated the crank to move to intake 3 so I could remove that shim and put in the 270 that I just removed. At that point, the intake 1 cam lob moved into the empty bucket. As I continued to turn the crank, the cam lobe came into contact with the inside edge of the lip of the bucket. I guess I assumed I could pull all of the shims out at the same time, swap as needed, then order the ones I don't have. I didn't realize the lobe would get hung up in the empty top of the bucket. I'm ready for the scolding I deserve, but I didn't see this mentioned. I suppose I'm going to have to pull the cam to get myself out of this mess.
How would you go about swapping shims to different positions without this happening?

 

Yes you can swap shims from valve to valve. But first, you need to have the one shim that will start the " chain if events" for the swap. If you have a situation where all shims can be shifted around, then either have a "surrogate", plastic, etc. shim to start with. Then dont forget replace that one ...

Some people have gotten away with rotating empty buckets.... Personally, I wouldn't recommend doing that.

You may be able to carefully and slowly rotate the engine backward to depress the bucket again. Put the ziptie/wire in. Rotate forward, Make some thin discs that can easily fit in the bucket, and build up enough to get the bucket to depress far enough to open the valve enough so that you can get the thicker ziptie or wire in. Once there, pull the thin discs out and put the right shim in.

Now you're back on track....

 

The plastic disc is a great idea, thanks!

 

Contact listmember " Polock ". He can set you up with some. Let him know I sent you to him.

Dave F

 

I did my very first valve check last weekend. In 30 years of ownership, I always paid the Yamaha dealer to do it, and not frequently enough.

I purchased the valve bucket tool from Chacal. Some have reported problems with it. I have a few lessons learned from a newbie to add to the discussion:

- On the valves where there was a bolt hole on the engine block near the valve, it was very difficult to get the valve bucket tool aligned properly. The tool was too wide and couldn't get square with the cam because of the bolt hole sticking out. Using a dremel, I ground the sides of the "bend" on the shim bucket tool to make it narrower right at the bend. After that, no problems at all and it worked great. I also was expecting the tool would keep the ring around the shim from moving up when you turn the cam up. When it came up with the shim, I thought it wasn't working when it really was. The shim still popped right out.

I purchased all new gaskets and grommets. To replace the grommets, I used a dremel tool to cut the old grommet off the bolt. Order the brass "thingy" (cone) from Chacal. Using it, the new grommet will slide right onto the bolt. I forgot I had bought it, and just about ruined the first new grommet trying to muscle it on the bolt. It doesn't come with instructions, but it is obvious how it works when you look at the bolt and new grommet.

If you are over 50, I also recommend knee pads on the list of "must have" tools...

 

I have the donut tool too. I like it and the price was well spent. Tried installing donuts with and with out tool just to see the difference.
even as a throw away too it is good after all how many times are you going to replace donuts.......

 

if you clean the bearing caps with brake cleaner and write the shim size on it with a "sharpie" next time you do the shims you'll know what's in there.
i didn't think it would work, but it did.
talk with Chacal about those plastic shims, he's your man