Please, I need help deciding what to do with my XJs

I apologize in advance for the wall of text.

For my high school graduation, my loving parents got me an 81 XJ650! So it's got a lot of sentimental value to me.
If Fitz's XJ is a toxic asset, then this one is surely a radioactive asset or something. I've put more money into it than any sane person would have. Seriously chacal is probably all set up for retirement after all that I've dropped on this thing.

Anyways, this January, I was driving my car and an asian lady turned left right in front of me and I totaled my poor subaru. I had the brilliant idea of riding the motorcycle the next day because I'm a man and the cold doesn't affect me. However, I overlooked the fact that ice does, in fact, affect me.

So now my bike just sits there and I get so disgusted with myself every time I walk by I can't even look at it. I'm pretty sure that it's fine (i.e. safe) to ride, I just need to bend back the heat shielding around the exhaust pipe that is interfering with the rear brake pedal, and deal with whatever is going on with the engine case on the right side.

But there are other things:
Cons:
-frame may be a tiny bit bent
-starter doesn't work, I've been bump starting it for years
-engine knocks a little when cold, getting worse slowly
-engine damaged in crash
-engine has been leaking oil from the tubes that run up the right side to the valves for a few years, i think the oring right under the head is leaking. It has ruined every right shoe I own
-bike is losing power slowly over time and I can't figure out why.

But on the bright side:
Pros:
-brand new tires and brakes
-xj750 seca forks w/ dual brakes. I rebuilt them maybe last year w/ performance springs and most expensive parts, but one is leaking again, probably got a nick in it that is messing up the seal.
-nicely painted
-i semi-rebuilt the engine about 4 or 5 years ago when the damn chain guide exploded. I replaced a lot of wear parts while I was in there.
-i am emotionally attached (or is that a con)


So it seemed to me that the best course of action was to get a new motor to swap in and be done with it, at least until the chain guide explodes again. Lo and behold, yesterday I found an 82 xj650 that's been sitting for 8 years but has no title. Guy only wants 150 bucks for it. I went to check it out today and the engine was really hard to turn over but it freed up after a revolution and seemed smooth at the very least. He said he had another buyer lined up and I figured I could at least part it out and get my money back (and some) if the engine is shot, so I bought it.

I got it home today and hooked the starter up to my new subaru's battery (thanks geico) to do a compression test. Here are the numbers:
115
110
dry: 85 oil: >140
105
Corrected for altitude:
144
138
dry: 106
131

That #3 cylinder is bothering me.

So here are my options as I see them:
1. spend the time and effort to pop off the valve cover on the donor engine and check the clearances. if they're out of spec, take the time and effort and money to correct at least #3. if they are already in spec, i wasted my time money and effort, and still have a low compression cylinder.
2.spend the time and effort and probably money to clean up the donor bike's carbs or swap in the ones from my XJ too see if I can even fire up the motor. hopefully if it runs a little it will clean up any rust or whatever in cyl #3 and increase the compression enough to make it worth my time money and effort to do the swap.
3. part out or sell the new donor xj, and keep looking either for another parts bike, or a known good motor.
3.5 part out or sell the new donor xj, and bite the bullet and fix everything that needs to be done to the motor on mine. at least then the serials will still match (does that even matter?)
4.part out or sell both bikes, even though I really don't like the idea of losing my baby.

Pics:
my bae:

bae damage (oil is from leaking oring, not the crash):

$150 missing title donor bike


If you could please just let me know what you would do if you were me. I promise I won't hold you responsible if I follow your advice and end up f***ing myself Thanks.

 

Make them like new, and go ride.

When engines sit, rings stick. When rings stick compression ges low. The same thing happens when valve clearances are not kept in spec.

Start with the one with the best engine (the non-leaky one) and work on the leaky engine last. That one will need to be split to replace seals anyway, so you can rebuild the starter clutch at the same time.

 

Looks like you got a good buy. I' m assuming you got a bill of sale? In Indiana there is a state form for bill of sale, with this you can get a title after the police inspect vin as long as it does not come back hot good to go. If you can get a title transfer all your parts to new bike then take your time on original bike , fix it at your leisure.

 

how do i respond to the right post? EDIT: haha I forgot how forums work. nevermind.

anyway

k-moe:
I like the way you think. Unfortunately, I just don't have the funds to make and keep both of them road-worthy.
I think I will try firing up that new motor to see if the compression goes up just from running and possibly scrapping the rust off of the cylinder, and as you say, un-sticking the rings, then go from there.

jetfixer:
yeah there's really no way I could say no at that price. I did get a BOS with the guy's full name on it at least. I wasn't really considering getting a title for it but I might as well figure out if that's even possible (CO). I suppose if I transferred over the carbs and wheels it might actually be road worthy at little to no expense, besides registration and insurance.


So my plan of action now is just get this new(er) motor running, do a few hot/cold cycles, and then check the compression, then go from there.

 

time is on your side, the bike has been waiting for you to find it and will not mind if you take your time .

 

Pillow..... Looks like any other Xj project to me.... I don't see problems. Here's what I would do first:

1- bend the brake lever back out so it doesn't rub the clutch cover

2- degrease the engine. Looks to me like a lot of oil is coming from the valve cover. Did you do valve shims? Is so, you should have gotten a new gasket as well. If not, do shim clearances and a new valve cover gasket. out of spec valves can cause performance loss.

3. Swap an engine cover.

4. Bend the heatshield out of the way of the brake pedal.

5. Swap the starter

Question-- why do you think the frame may be bent?

 

Thanks for your advice, hog. I thought the cases had to be split to replace that right side cover, I guess I was thinking of the seal that goes behind there. The major leak is not from the valve gasket; it's either the head gasket or the o ring that's there for the oil tube, that's wrecking my shoes. My dilemma here is that if I want to fix that leak, I'm gonna have to pull the head, and maybe the jugs if I wreck the base gasket removing the head. And I don't want to do all that work if the knock gets bad enough to warrant attention. So I'd really just like to swap a new engine in there for the time being...

I think the frame might be bent because a few years ago I did a low-speed slow-motion high-side and the bike came down on the right side handlebar. It was really quite spectacular if I may say so. Anyways after I got the thing back together, turning left seems different than turning right. Like it takes no effort to lean over left, but it takes a little more umph to get the bike to lean right. Not really hugely noticeable, but I can definitely tell there's a difference. Maybe the lower tripple is bent? the upper was replaced after that crash at some point. seems to me like that cast aluminum would crack before it would bend though.

 

My bet is that you just twisted the triple, and your forks are out of parallel. Loosen all tube clamps, straighten them. Tie two broom handles across them... One near the top, other near the bottom. Sight down the forks, and when sticks are parallel, so are the forks. Tighten everything back up, keep checking as you're tightening.

 

Yeah I've had the forks out of the clamps many times, unfortunately

 

Nice buy on the parts bike, swap the engine, i would,nt worry about matching #, even more so if it's always going to be UR baby. You can never going wrong keeping a parts bike or any vehicle for that matter. I've been stealing bolts and clips and other small items off a junk bike my son drug home bout a yr ago, not even sure what kind it is and don't really care, it has metric chrome bolts and wire harness conectors and rebuilt a cluth lever switch from the one on parts bike.

 

But did you check to make sure they are parallel again?

I just don't see enough damage to indicate any hit hard enough to tweak the frame

 

I haven't actually measured the forks to see if they're parallel. In my mind just having the whole steering assembly loose was enough to get it straight. Although when I put on the front wheel, I have to pull out the right side fork about 1/8" before I tighten that clamp on the bottom of the fork to keep the disk from rubbing in the caliper... I think I remember reading here that other people have had the same problem and passed it off as normal...

 

Never assume. CHECK them.

Pulling one fork out farther than another so the brake doesn't rub is NOT normal.

 

On the never assume front....there are plenty of places where a leak from the valve cover can run and make it look like the head gasket is leaking. Same goes for a leaky cam chain tensioner gasket.

 

You were right k-moe! I decided to just use the title-less bike as a parts bike, and while I was swapping the engines, I had some penetrating oil sitting in the questionable cylinder. When I first fired it up it wasn't smoking anymore, and after two weeks of riding it hard, I checked the compression again:

Before Now
115 145
110 135
85 130
105 140

And if I correct those numbers for my altitude, I get 182 169 163 and 175, which makes me believe chacal's formula isn't correct, haha.

 

If you are talking about this:

NOTE: for readings taken at locations that are above sea level, the following correction factors should be applied to the readings that your gauge obtains:

- 1000' above sea level, multiply your readings by 1.029 to get a "true" compression reading.
- 2000' above sea level, multiply your readings by 1.060 to get a "true" compression reading.
- 3000' above sea level, multiply your readings by 1.093 to get a "true" compression reading.
- 4000' above sea level, multiply your readings by 1.126 to get a "true" compression reading.
- 5000' above sea level, multiply your readings by 1.160 to get a "true" compression reading.
- 6000' above sea level, multiply your readings by 1.196 to get a "true" compression reading.
- 7000' above sea level, multiply your readings by 1.233 to get a "true" compression reading.
- 8000' above sea level, multiply your readings by 1.272 to get a "true" compression reading.

those correction factors are absolutely correct! And except for the #1 cylinder, all of them are within spec:

XJ650 and XJ750 air-cooled engines:
Minimum: 128 psi
Standard: 156 psi
Maximum: 171 psi
Max. variance between lowest and highest: 14 psi

Remember, factory specs for compression assume a cool engine (60F) and sea level measurements. If you took those measurements at 8000' ASL, then you should apply the correction factors listed.

Why is #1 too high? Could be some carbon build-up on the piston on the head, a bad gauge (in which case all of the readings are probably too high), or a couple of other possible odd causes.

Also, it is critical that the air filter is removed, all spark plugs removed, throttle held wide open, battery fully charged, engine at about 60F, etc. It's actually recommended that for purposes of compression testing that the TCI be un-plugged and jumper cables to a large capacity battery (i.e. car battery) be used to make sure that the cranking speed remains pretty constant between each reading. Slower cranking rpms on a cylinder will reduce pressure readings due to blow-by (leakdown).

 

To add to that ^
The correction factors are used without taking into account local barometric pressure. If you took compression measurements during a strong weather event you would need to take the actual local barometic pressure into account instead of using the above correction factors.

 

^ very true.

 

I'm sure your mistaken.

 

..Iiiiiiii'm-a warnin' ya----

 

I know this is a bit off topic but that parts bike has some item's I'd love to purchase (especially the header pipes). Is there any chance that'll you be heading over to the Sale/Wanted section and selling some parts off of the $150 bargain?

 

Just a bump -- any chance OP could PM me?

 

Hey man just swap the front ends it's no biggie drop the 50 bucks and get some tapperd neck bearings it's worth it and you'll probably lose all the ball bearings anyways hahaha I did, you swapped the motor so when you got the time take the other apart rebuild better faster stronger, rip the one you got till it's ko'd and swap again and repeat for best results. I got 2 750s 2 650s and a 550 my lady rides trust me I feel you on the xj love shoot I got a YICS tattoo