Help with my 82' XJ550

I've got a long one so feel free to answer in bits and pieces.
I acquired this xj550 around a year or two ago in hopes of building a cool cafe racer project. I had just started college and wanted something to wrench on over the summer that could turn into a fun little toy. I have little to no mechanical background, I've done a couple of lift kits, changed some brakes, and maybe some spark plugs but didn't realize how in over my head I was until I began working on this thing.

The day I brought her home

I love a good challenge so I made it my goal to get this ole girl running like a top. It came with the rear chopped off (the previous owner tried to make a cafe racer) and no air box (again... cafe racer). He had given up on it a couple of years prior even though this was the exact bike he learned to ride on in the 90s. Despite the huge red flag, I decided I had $200 bucks to offer and took her home the same day. I watched tons of youtube videos and after lurking on here for a while, rebuilt the carbs, got pod filters, replaced the intake boots, and rebuilt the carbs again and again. I got it running all right a couple of times but nothing permanent. It progressed to the point where I could start it pretty easily but then it would take off and rev bomb to the moon, I assumed air leak and replaced the boots but it continued. Now it doesn't start at all so I began toying with the idea of the valve clearance being off. Measured it and got these measurements.


I know these are off and was attempting to get the size of the shims when I saw these holes near the spark plugs outer ring.



These are two separate holes each on the outer spark plug (left and right).
Now with my limited mechanical knowledge, even I know that holes in anything related to the engine are BAD. Can I just throw some JB weld on them and send it? Is the entire engine toast? I honestly don't know, I assume it was like this when it was running a couple of months ago.

Another thing that concerns me is the amount of oil on one side of the engine compared to the other. With the valve cover off the left side is full of oil and wet while the right side is almost dry in comparison. (PIC of dry right side)


(pic of left side)

Again, no mechanical background so I'd love to know if this is just a bad gasket and I could top it off with oil or if this means catastrophic failure and I'm better off buying a new engine.


The dried out brown part is on that right side that was dry so I assume this gasket needs to be replaced either way.

Also, the spark plugs look horrendous so i'll just throw a pic of those in as well.


This thread is kind of my last hail Mary in an attempt to see this beauty running again. I guess I'm just looking for answers or any insight as to what my next step should be. Should I continue where I left off and try fixing the clearance? Should I forget this complex stuff and rebuild the carbs again? Should I scrap the entire project and buy a boat?

I definitely should have came here and asked the pros for help sooner but any and all help is appreciated. Please feel free to offer your opinion or ask any questions. Thanks!

 

1. Those "holes" look to just be casting errors. The larger of the two is actually supposed to be larger (see the other side of the head for reference). Nothing to be concerned about (Yamaha didn't think so, or else the head would have gone into the scrap pile to be remelted).

2. You're off to a good start. Valve clearances do need to come first. Yours are out enough that it's likely the main reason she wasn't running. Begin by doing some reading, and then get the vlaves in spec. @hogfiddles runs a shim-pool; the only cost is postage.

http://www.xjbikes.com/forums/threads/read-this-first.110898/

https://www.xjbikes.com/forums/thre...valve-adjustment-with-pics-parts-i-ii.116006/

3. The valve cover gasket needs to be replaced. @chacal has every part that can be had for these bikes (even some parts that are no longer in production, though that stash is getting smaller). Check the rubber parts on the valve cover bolts. They are what provide pressure to seal the gasket, and not the bolts themselves (tightening the bolts beyond their torque specification will crack the head, as the bolts bottom-out on a shoulder). If they are as hard as the gasket, then they should be replaced too. Instructions are in the valve clearance link provided above. Check the valve cover for flatness by placing it on a granite counter-top, or a sheet of glass. It should lay perfectly flat. A minor oil leak from the valve cover is common, and not really of concern as long as you're not needing to add oil on a daily basis and not messing your pants with oil.

 

I modified a shim worksheet that was made for the MaximX and sent it to @hogfiddles to upload. This makes it very easy to calculate shims needed.

 

I’ve never had to calculate anything… I just look at the standard chart

 

Some may not have access to the charts. This worksheet makes it much faster and allows the moving around of shims to see how the outcome works out before moving/replacing anything.

 

That’s fine.

suggestion...change the caliper picture to one that has the 29mm shin instead of X-shims

 

Everyone on this site has access to the charts though...

 

As someone with a slow-working brain at times this Excel sheet did help me clear things up (I double-checked with the chart).
I waited a couple of days for the valve tool to come in only to realize it didn't really work like it was supposed to so I went back to the zip-tie method. I guess something clicked in my brain today cause I was able to do it perfectly for each shim.
The buckets were pretty stuck on most of them but I was able to pop them out eventually.

I sincerely appreciate y'alls help and will keep this thread posted once I get some new shims in.

 

This is why I just use the standard shim chart. All the in-between numbers are totally irrelevant. The sizes are in 5’s....
270, 275, 280, 285, Etc......

either you are in spec or you’re not.
263, 274, 279..... those numbers mean nothing. If you use the standard chart, you:

1. find where your measurement is in the left column
2. Find your current shim size in the top row
3. Read the number where they cross for your new size to install. In spec is in spec. Out of spec is out of spec.

 

Me too, great ain't it.

 

New shims (thanks to hogfiddles) and valve cover gasket in, the bolts and their gaskets looked fine in my opinion. Clearance measurements check out but I'm still having issues with idle taking off and only starts/runs with choke. I have some cheap intake boots from ebay that I suspect are the vacuum leak/idle issue since the brass fittings aren't glued in very well and come out with force. I replaced them with the oem ones with a little sealant on the tiny cracks to try tomorrow.

I'm also noticing fuel leaking from the fuel tee it looks like, would this prevent the bike from starting without choke since it's a different circuit? It's a sizeable leak but I feel like it wouldn't block fuel from going through completely. It could also be fuel level but I've dry setted them with the measurement tool and the measurements looked correct. I've been using an auxillary fuel tank with a simple on/off valve for testing and a cheapo inline fuel filter just incase the tank was a little dirty, could these be a culprit?

I appreciate everyone's continued help.

 

Still having the same issue, I sprayed all around with starter fluid and could not find the leak. The sync guage shows constant zero on all four guages. Starts with fluid/choke but immediately idles up then dies.

 

The fuel Tee leak won't prevent it from starting, but if its sizable as you say, you might want to fix this first before a fire.
Are you absolutely certain the throttle isn't cracked open by tension in the throttle cable, causing the runaway rpm? Maybe unhook the cable at one end or the other to be certain, or screw the adjuster just below the throttle grip in all the way so no threads show.
All 4 gauges reading zero...do you have the type with small shut off valves below the gauge, and are those possibly screwed closed?
After you swapped valve shims, did you recheck the gap with feeler gauges?

 

The throttle might be a little cracked open but I don't know if it would cause this high of idle. I have the bench sync set so that there is some light coming from through the butterfly valves as seen in this picture from youtube.
The gauges do have the shut off valves so I untightened them and saw more movement, still far from the green though.
Also I did recheck gap after a couple rotations with new shims and everything seemed fine.

I don't know if this is indicative of anything but when I tried choking airflow by physically putting my hand in front of the air intakes the idle shot up a bit.

 

It doesn't take much throttle to rev to 6 or 8k from idle. Definitely first check that the throttle is closing. Back the idle adjuster screw off (the horizontal screw in the middle, adjusted from the rear) till it visibly has a gap and it's not opening the throttle. Then adjust the cable coming from the twist grip so there's visible slack, or disconnect to be absolutely certain. Then see if it still runs away when starting.

Remember that the bench synch is just taking a stab at getting the carbs opening the same...synchronized. It does not set the initial butterfly position for idle. If your throttle was open as much as your photo shows, it would probably redline.

 

The idle screw was turned in a good bit so you were right on that front.
I decided to do a full tear down in order to see if there was any grime in the jets when I noticed that the pilot jets were completely wrong (thanks ebay rebuild kits). There was one correct one and the other three were way smaller with a different nozzle. I have a jet kit coming next week that will probably help a lot in addition to your suggestions.