XJ650 Starting issues

Well that's the thing, I was tightening it by hand on one of them with the hex, until it was snug, but it was still leaking, and I remember tightening it more until I started hearing a slight creaking, and then I stopped. It was still leaking (slightly). As this was happening the fuel in the tube was lowering (because it was coming out of the drain screw, cause I had turned off the aux tank at this point, which shouldn't have mattered because there's still fluid in the line and gravity should refill it.)

I went back to using the brass screws and I did this enough times to feel comfortable that I didn't drastically overtighten the drain screws, it was just seemingly a function of physics? Or something. It doesn't happen unless there is gas on a hose attached to the nipple causing some sort of static pressure

 

With these dissimilar metals (stainless doesn't like alloy castings or aluminum), I'd put either grease or anti-seize on the threads to prevent fuel from wicking out the threads. Of course, those lubricated threads now need less torque, so use the usual caution against overtightening....

 

That's what I was thinking, but I was worried about getting anti-seize into the fuel and clogging the carbs

Also no local location sells nickel anti-seize, it's all copper. I'd have to yet again send Len money

 

I erroneuosly said to leave the drain screws open, of they should be closed. Are you sure gas is coming out through the threads of the screws and not from the tube nipples and migrating along the bottom of the bowls to the drains? Your setup has static hoses attached and not easy to manipulate. If closing a drain screw raises the level in a tube, you just need to lower the tubing so that more fuel will flow into it and level off at the same level as inside the bowl. I do one bowl at a time with one, longer piece of tubing which I hand hold vertically. I can lower it to check the level as more fuel is entering the bowl. Just never raise it because the fuel in the tube will not be accurate.

 

Why not?

 

This is the setup that I had to do in order to get the carburetors level. I had bought a k&l carb rack on eBay but I had so many problems with it. I just clamped it, but then I had to stick wooden shims under it in order to make it level because the thing that the carb would attach to didn't actually fit even though it said that it would. And also didn't have any instructions that came with it.

It's not stupid if it works

I also attached what the carbs look like attached back on the bike

 

Trying to make sure that I don't over tighten this, what is the torque spec of this?

I set it to 2 lb, that seems like enough.

The most frustrating thing about all of this is when the shim doesn't perfectly go into the bucket, and you have to like make sure to lube it up and to stick like a hard feeler gauge in there and try to make sure it's as level as possible

 

Doesn’t need to be a whole lot. Just enough to hold the bucket down. About 1/4~1/2 of an ugga-dugga

 

Being inside of the engine always makes me really worried. Anyways, I've replaced three of the shims on the left side that needed replacing and now I just have to do all of the ones on the right side

Annnnnnd of course the intake 2 shim is off by .01mm, which means the spec was .11 not .1.

I'll have to put the shim back because technically that one was within clearance

 

Alright, I finally finished with the valve clearance and adjustment, here are the results:

Left to right:

E
.2 .2 .16 .16

I
.11 .11 .14 .13

I think it would probably be good to check these clearances again in like say, 500 miles, since intake 1&2 and exhaust 3&4 are right on the wire of being in-spec, and then rotate back to a 5000 mile valve check. Only really because I don't have any frame of reference to how long these valve shims last for! (Yes, I understand it's not the shim's fault, it's the valve's fault for seating further into the head, but you know what I mean)

Once I replaced the shim, I would rotate the engine and then check the measurement again, to make sure the shim I put in actually ended up being okay. I forgot today was voting day, so I went and did that and headed over to the bike. I thought this would take 2 hours, since I only had to replace 6 more shims. Instead it took four. Part of what took so long was once I replaced Intake #2 shim, I realized my measurement was slightly off, and by going down 5 it actually put me out of spec. (in effect, I only needed to replace 6 shims, not 7 of 8). I noted this and left the wrong size shim in there while I moved onto the others, and would put the original shim back in later. (I thought I had measured .10mm, but it was .11mm, so when I went down a shim size now the gap was .16mm not .15mm. Oops.)

The other wrinkle was when I went to put some of these shims in, looking at you exhaust #3, it would just bounce around on top of the bucket and I spent a bunch of time fudging with the damn shim trying to get it to fit back into the bucket. Since I had cleaned up a little bit of the oil that was collected in the top there, it was a little dry, and when I had measured this the first time around to know what shims to buy, I didn't really oil the shims after wiping them off with a rag to look and see what I was working with. When I installed the new ones however, I made sure to let them soak for a few minutes in some T4 Rotella oil before installing. Most of these were fine but some of these were a right pain in the ass. I also had some assembly lube on hand which was rather handy to just put like an 1/8 of a teaspoon on the bucket and tried to see if that would help, along with a minuscule (less than a cap) of oil to try and help with the install. I got it eventually but some of these would not want to seat easily and I struggled with that for a while.

Then, when I measured intake #4, which had a 305 shim in there, and all I could get in was a .03mm feeler before, I decided to go down to a 295 shim. Measured .03mm with the feeler gauge, so to get it in spec, you must add .1mm right? WRONG
Intake #4 had negative clearance. I didn't need to go down .10mm, I needed to go down .15mm to put myself in spec. uh oh. Three shim sizes from a 305 to a 290? WTF

Thankfully, the shim I had planned to install into intake #2 instead would work for intake #4.

Again, after every time I installed one, I went back and double checked, mixing feeler gauges to make sure. Was I sure this was .16mm? Could it be .17mm? What about .15mm?

So, of course, this took forever. People are like, yeah stick a screwdriver in there and pop it up, I tried that and I struggled with that. What worked was using my ex's air compressor, though. Blast some air at the notch and unseat that stubborn wafer. This worked pretty easily, except for when it blew back oil into my face and hair, thankfully I was wearing my glasses but ugh.

So with the adjustments installed and double checked, I took out the hi-tack (god this stuff STINKS) and a crappy little brush and tried to get it in the valve cover crevasses, though it loves to leave little streamers everywhere, and then installed the gasket. I didn't think I needed it, because previously the gasket was doing a decent job being held in by tension, but I bought it, may as well try it out.

I then got the black sealant gasket and tried to put a little bit on the half moon circles, but of course the tube had other ideas and it all came out in a blurp. I wiped as much as I could off the rubber with a towel and finger and just gave it a decent coating on the half-moons, not "i really love cream cheese and want a half inch on my bagel" amount of gasket, but a reasonable amount of "coat the toast with butter" amount of gasket.

I then put the valve cover on. I had got new rubber grommets installed on the valve cover screws, and put the center ones in first, tightening them by hand until they were...snug? (imagine me shrugging my shoulders) because there wasn't enough height between the valve cover and the frame to get my torque wrench in there with the hex head.

I did tighten all the 8 outside screws which I could get to, to about 60 inch pounds, which based on trying to gently turn them with the hex key, are probably tighter than the center screws, to be fair. I heard "no more than 7.2 ft pounds" so I made sure I went under because, with doing all this, my smartwatch thought I was going jogging, when I certainly wasn't.

Anyways, valve clearance is done

 

Also, one of my friends locally 3D printed me the STL files from the forum, to block off the petcock and the sending unit and the gas cap cover.

And I just got in my paint and stencils, for the new tank. I'm really excited. I probably won't have time to do anything with the xj750 tank this week, it might be next week or the week after.

 

I would recommend trying to get all of the cover bolts (inners and outers) to the same tightness, as much as is possible even w/o a torque wrench, otherwise.....as uneven force on the cover is how valvecover warpage occurs over time.....and you really don't want that.

If you have a scale (i.e. a bathroom scale or the like) you can "calibrate" your hand pressure by trying to mimic the "feel" of the pressure you're exerting. So go tighten the (or "feel" how much pressure your hand is feeling) on the outer bolts, and try to duplicate that amount of pressure by pushing down on a scale. Then try to imitate that feeling-of-pressure on the other bolts. Without using a torque wrench, that's about the closest you can come to "accuracy".

Of course, if you have a bolt that is known (via use of torque wrench) to be a 7.2 ft-lbs, then you can do the whole scale-feelie-thingy at a known torque, and you can duplicate that on a scale and maybe it ends up being around 10 lbs of downward force on a scale (which you now know = about 7.2 ft-lbs on a fastener).....recall that "foot-pounds" is how much pressure is being applied on/at the center of a fastener when you are applying "x" amount of force (downwards or sideways, doesn't matter) at a point exactly 1-foot (12 inches) away from the center of the fastener.............hence "amount of force applied 12" away from the fastener = FOOT POUNDS.

So if you apply the same amount of force (let's say 10 pounds of force) at only a distance of 6" away from the fastener (using a short wrench), you're only applying 5 foot-pounds or torque (since you're applying the 10 pounds of force at a distance of only half-a-foot away (6") from the fastener....10 x 1/2 = 5 ft-lbs.

And always remember....the use of anti-seize on threads reduces the amount of torque that a fastener should be torqued to.....unless the service manual already specifies that a fastener should have anti-seize applied to it (in which case the specified torque value in the manual is correct). On any fastener where anti-seize is not specifically specified, the use of anti-seize will reduce the torque needed by up to 10-15% in steel, or up to 25% in aluminum or other "soft" metals.

 

I'm not going to be back over there until Friday, but I can tighten the center four bolts down then a bit more.

They certainly could be tightened more, but, reading that it's really easy to crack the head, that leads me to not tightening it as much as I would initially be keen on doing.

 

"Less is more" when it comes to valvecover bolts........

 

One thing that really irritated me about the valve shim tool was the fact that I'd have it seemingly perfectly aligned, and I'd tighten it down (even to 2 ft lbs) and as I'd rotate the engine to raise the bucket, the pressure of the bucket would push against the tool, causing it to shift slightly away from the engine.

My fix? as the bucket would start to apply pressure to the tool, I would put downward pressure on the tool and hold it in place, and just holding my hand against it with decent pressure would be enough to keep it from shifting. Made me wish that there was another bolt or something in there instead of 1. Also, this would make it awkward because you'd almost have to have 3 hands as you're leaning over the bike.

also things that made my heart rate skyrocket, I would rotate the engine (sparks in) CCW towards the front, and it would go from being very easy to turn, to needing some tension. I would go very slowly, flipping the wrench I got from len (since it was thicker on one side than the other, so it would change how much distance your rotation would travel) while making absolutely sure to not touch the pick ups on the ignition timing plate. This would be the case in CW and CCW, but especially slow with CW (reverse) motion. The engine being easy to turn at certain points in the rotation and harder certainly made me nervous, if only because I just assume that's normal but my anxiety goes "yeah but what if it isn't and what if you, even though you've spent hours of research reading and watching videos and reading manuals, even though you think you've been excruciatingly careful, what if you broke something?"

Couple this in with not having a good working space, and tools are just kind of...everywhere, trying to have a system, and then going like "where the **** did I put that, I was just holding it!!" only to find it is literally right in front of me

Anyways, compression test on friday afternoon, if the engine does the compression test and doesn't make any expensive noises then I know I didn't. I don't think I did, I certainly feel like I was careful, but there's that little voice...

 

Lol yes. To everything you said.
Sounds like it's going well!

 

Cross your fingers for me or something cause all I need to do is:
1. put battery back and screw airbox back in and such
2. do compression test. if it doesn't make expensive sounds, continue on
3. hook up aux tank and hook up carb tune pro, and hope and pray I don't make things worse somehow, because setting these butterfly valves to be close was a fiddly pain in the ass
4. turn bike on and pray it doesn't explode (more likely that it just won't turn on and I will need to use starting fluid or something)
5. once bike is tuned, then change the oil. IDK if the last tech did so and i want to be SURE. I know what I did to this bike, and I'm making myself a "service history" excel sheet where I cover what I did, on what date, and what mileage it was at when I did it.
6. replace the front inner fork tube, I have an extra oil seal on hand in case I need to replace it, but I really think the steps are just going to be; take the fork off, take cap off, take spring and spacers out, drain fluid out of container, unscrew bottom hex bolt, pull inner fork tube out, put brand new fork tube in (god it looks so damn nice), and reverse order of install.

after that she should be good to go...barring any other new things happen...as working on an old bike is wont to be.

My next project for this bike?

With how hot the summers have been, I think I have two priorities:
1. install bigger 750 maxim tank I bought so I don't have to refuel as quickly, and strip the existing paint and clean out it's insides, and get ready to paint it glittery pink. I got stencils to go, and a vision and everything!
2. install an oil cooler, the Maxims deserve it, and I want this bike to last as long as possible.