Oh No!! I've got a big problem!

[Shawn27530]

Ok, Off it comes, I'll let you know what happens.

[Shawn27530]

removed the head

Well the head is off, and the problem still exists. Actually the head and valves etc. look really good. Still it will only go that 3/4 of a turn. I will continue to tear it down.

[TopCatGr58]

Well, Shawn,

IF you end up swapping the motors, and you do get the whole donor bike, you'll probably want and need to swap the ignition box, cause the 78 engine has both centrifugal and vacuum advance mechanisms on the left side of the crank. The XJ only has the pickup coils, the other advances are controlled by a separate vacuum sensor box and chips in the newer TCI. Also, the older bike uses a ballast resistor cause it had coils with lower ohms....1.5, the newer 81XS and XJ's use the higher 3.0 ohm coils and don't use the resistor. You should have no problems using the XJ coils with the older TCI since the newer coils don't need the ballast resistor anyways!

The XJ carbs should work just fine on the older motor, and should be easier to synch since you won't have the YICS porting!

With the engine spinning just so far and stopping, it's hitting on something. And since the topend is clear of FOD(foreign object/debris) then must be something in the bottom below the pistons, either a broken piston skirt, or else getting caught on and between the balance sections of the crank and the case?? Will be interesting to find out what it is!!
T.C.

[Shawn27530]

Yeah, I am real curious to find out also. Next I am going to pull the cylinders off the pistons and pull the oil pan. Maybe all this investigating will help someone else in the future.

I called one of my friends in Maryland last night, and guess what I found. A Midnight Special with 2,326 miles on it, sooo, the XJ will get parted as soon as i ease my curiosity about what the heck is wrong with it. And I am going to buy that bike. It looks really good in the pictures. I asked him if he was sure it was only 2k and not 102K and he said it is documented and he will show me the paperwork. I am going to ask for a compression test before I go all the way up there though.

[DeanR]

Shawn, are you doing this dismantling with the engine still in the bike?

[Shawn27530]

Yeah the engine is still in the bike, the more stuff I take off of it the lighter it will be to get it out of the frame.

[Shawn27530]

Fair Price for engine

Hey guys,

What is a fair price for and 1100 engine. There is a guy selling one on ebay for 450.00 (BIN only) and I think that is a little steep.
And there is another one that I want to bid on, its minus the ignition on the left side, and off course the carbs and boots. So I should be able to swap all the XJ ignition onto the left side right?


Update on XJ engine: I can not get the dang cylinders off the pistons and I don't want to pry against the case and head. I tried a few methods that me and wingnut talked about but that sucker is on there. Any tips?

[fxrer]

Wow, that doesn’t sound good. Were you able to move the cylinder up at all, and just can’t get it above the pistons? Or is it that you can’t break the cylinder free from the case?

If the latter, the book says to tap lightly around the base of the cylinder with a plastic or rubber mallet. “If necessary, gently pry the cylinder loose with a broad-tipped screwdriver ONLY in the area of the two pry points.” These pry points are at the front side of the motor, at the bottom between cylinder and case, right above the boss where the motor mount bolt passes through.

If it’s the former, maybe whatever is keeping it from coming off the pistons is the same thing that prevents the crank from turning more than ¾ of a turn? If that is the situation, you’d have to pull the engine, split the cases, and come at it from the bottm.


Good luck

[TopCatGr58]

Hey Shawn,

That price does sound a bit steep!? For a bit more than that, you can have the big bore kit installed!

As for the XJ engine, sounds more like there may be a large deposit of RUST inside one of the cylinders? Perhaps one that had the valve(s) open to the atmosphere, either intake or exhaust, and humidity and vapor got in and rusted the cylinder walls pretty thickly?? I know I had a bit-o-trouble getting my cylinders off due to corrosion around the case threaded rods that the head nuts bolt onto, as well as RUST in the cylinders!

I just checked the parts fiches, the crankcases and crankshaft are the SAME for the 78E and the 82XJ, so you should be able to just bolt the XJ's pickup assembly onto the older engine, and keep all of the XJ's electrics!! They even show the dowel pin sticking out of the side of the crankcase around the crankshaft!
T.C.

[John]

Shawn

I ran an XJ engine in my 80SG for many years. The ignition pieces from the 80 went right on the XJ's engine. You will have to remove everything ignition related from both engines and swap them out, but it will all just bolt right up. Remeber the XJ has an oil level sender in the oil pan, and the XS doesn't. If you should swap engines, and want to keep keep the oil level warning system working, you will need to swap oil pans. You will need to swap out the alternator windings and rotors also, but this is a direct swap also.

[Shawn27530]

KUDO's

You guys are awesome! Lots of info between you guys' ears for me to pick out. Thank you.

[prometheus578]

Method of last resort...

Update on XJ engine: I can not get the dang cylinders off the pistons and I don't want to pry against the case and head.

Hate when the base gasket bonds the cylinder to the case! Ok, method of last resort...
Now I know that the thing doesn't crank all the way around, so you'll have to figure which pistons will meove enough.. whether to use #1 and #4, or #2 and #3. I'd say 2 and 3 preferrably.
Depending on how much room there is in the cylinder... wad up two or three shop rags and place them in either 1 and 4, or cylinder's 2 and 3. Put the head back on (CAMS REMOVED), and bolt it to the cylinder with just using the two 10mm nuts that come up from underneath, in the middle of the engine.(One is by the cam chain tensioner) (having the cams removed ensures that all the valves stay closed)
Ok... we now have the engine put back together, with rags stuffed into two cylinders.. #1 and #4, or #2 and #3. cranking the engine now will push the pistons up, compressing the rags against the head, which wants to push the head up, taking the cylinders up with them. At least enough to break the bond of the base gasket. Again... other's may disagree.... but like I said, last resort time... better than smashing cooling fins.
As the engine won't spin all the way.. you need to check the travel to make sure that you'll be using the right cylinders... ones that can move up on their rotation.
Yeah, yeah, yeah... I can hear it already. But I don't think there will be enough pressure to warp the head... (especially if using the two middle cylinders), but as always, I welcome comments.

[GNEPIG]

.. how about if they put the bike in fifth gear and roll it back and forth in the space that the engine moves.. this might tell them if the cylinders are what is causing it to be stuck, if it is the cylinders then this might help to release them from the case
..i have freed up frozen motors this way

[mro]

Method of last resort...

I'm a torchy kind guy.

Heat the front and it should only take a little tapping/prying to get it off the gasket.


mro

[Ken Talbot]

Back to basics first, by spending some time, using a large quantity of penetrating oil or solvent, and some fine, angled picks to remove all of the crap that builds up where the headbolt studs go through the holes at the bottom of the cylinder block. Over time, all sorts of stuff collects in these holes around the stud and bakes on to form an impossible to move plug that will keep the cylinders from moving up. I've done a couple of these, and neither base gasket was glued. The problem was just this build-up in the holes.

In this photo, you can still see some of this build-up at the bottom of each of the studs, and this is after they were cleaned up enough to get the cylinder broken free.