XJ650 Seca Seized Engine Help

Hi everyone. I recently purchased a 1980 (Australian model) XJ650 Seca from its second owner for the princely sum of $500, so although it looks complete, I'm under no illusions that it will be perfect. It has about 56,000km on it and although dirty from country dust, it's in excellent condition.

I've progressed through a carb rebuild but when it came time to turn the engine over, electrical issues prevented me from doing so. However I can't even turn it over with a roll start or by crossing the solenoid terminals. It appears to be stuck hard. PO had described a flood of fuel from the carbs and then left it for a couple of years completely drained, so I'm guessing zero oil anywhere.

So before I rip the head off and look further I was wondering if you had any obvious steps I could look at? So far I've done the following based on the extensive information on this site:
- Removed and tested the starter - it's all good
- Opened the left shifter case and looked through the inspection hole for guide breakage - all clear and in great condition in there
- Poured ATF and Acetone in a 50/50 mix into the cylinders and left them for days, just bumping the bike in 5th to try to loosen up possible stuck pistons - no dice
- Removed the left crank cover and used a 19mm spanner to turn the crank - little to no movement

It feels like stuck pistons and I can deal with that but before I settle on root-cause is there anything else that can seize it?

Thanks in advance.

 

Next is pull valve cover and see if any valves stuck down with big clearance to cam
Try diesel in cylinder and heat from head gun for a few hours or more
Next is try a propane torch on each cyl
Were any of the plugs rusty when you took them out?
with no oil and was full of gas at some point rings are probably rusted to cylinder
If all fails go looking for a spare engine (750is a direct drop in) just a touch of rejet or use 750 carbs

 

Thanks for the quick response! I'll pull the valve cover tonight then heat it up a bit after that.

Plugs were surprisingly clean - bit rich on a couple of cylinders but no rust whatsoever.

 

I'm out on the wet coast and I have had many bikes lock up after sitting a few years from rusty cylinders.

 

You shouldn't need a complete engine. Just the cylinders and pistons if you find that the ones you have are badly damaged from the seizure.
Not sure what the parts availability is in OZ but you could do a 750 crank, rods, pistons, and cylinders if necessary. Just be aware that using just 750 pistons on the 650 crank/rods will give extremely lower compression. You need the complete assembly if you go that route.

The XJ750A would be your same bike with the 750 motor in it and was available in your market. Its also very possible that you might have gotten the XJ750E in your market which is a fuel injected version. Just to give you a couple possible option for parts.

If you come across any OZ based parts diagrams in your searches. Please post the links for them. I would like to have a look at them.

~Ghost

 

Will do MiGhost and thanks for the feedback guys. I'm still hopeful that I won't need any parts given the good condition of everything else. The bike was in a shed in what we call the Wheatbelt which is inland country areas in Western Australia. Dry and hot during summer, dry and cold at night during winter.

 

Valve cover is off and all the valve clearances look fine. I'm wondering if I pop the head off or try heat first. Any opinions?

 

Heat first with diesel in the cylinders. Try and
Free up the engine before you pull the top end

 

If you can borrow a block heater that would be best. It'll heat the cylinders evenly without risk of damaging o-rings, or starting a fire. A heat gun will also work, or a torch with a diffuser tip.

 

Have even seen a hot plat under the engine set about an nick from the oil pane and left for an hour or 2 and wrap cylinder wth foil to keep the heat in but remove exhaust first

 

I have to say... that looks like a nice bike... especially for the price. Hope you free it with minimal expense.

 

how can you check clearances without turning the crank? If you turn the crank then the pistons are moving...

 

He couldn't have, without removing the head.

 

i quoted the wrong post! but... yes i think its odd he said the valve clearances are in spec

 

Sorry, I wasn't very clear with what I said. The valve clearances looked fine, not in spec - i.e. there wasn't a huge clearance indicating a stuck valve.

So by way of update, I used a heat gun for a while on the block (both sides) with penetrant in the cylinders. No difference so I got heavy with it and removed the head. Again, valves are fully retracted so no issue there. Cylinders have evidence of surface rust, particularly #2 and there was quite a bit of crud in there mixed in with the fluids. I've cleaned it all up and sprayed more WD40 in just to keep it soaking.

Next step is to wait I guess. I'll keep trying to move it but is it possible it's something else? Just to cover my bases, I'm happy to eliminate other possible causes.

 

WD-40 isn't a penetrating oil.

Make sure the transmission is in neutral. You might want to go ahead and remove the clutch basket just to make sure the transmission isn't the culprit.

 

Good point - I'll grab some diesel.

I may have eliminated the transmission earlier when I tried turning the crank from the 19mm square plate thing under the left crank cover. It was in neutral and still wouldn't turn but now I have the head off I'll give that a go again.

Thanks for the help so far guys. Very much appreciated.

 

If the shift forks are bent, the transmission may not be in neutral. If the alternator chain guide has failed, a chunk may be preventing the input shaft from spinning.

 

take a block of wood and a hammer and tap the front then back of the pistons, not the top or sides. keep tapping harder, if it doesn't break loose, start unbolting your new boat anchor.

 

Seeing that there is no Airbox.... And not even pods on the carbs--- could be any number of things, not just rain, could have crawled in there....

 

Wouldn't it be creepy if there was a skeleton?

 

Hehehe, maybe a mouse skeleton. There was lots of mouse cr4p in the airbox!

She's soaking in diesel now, so we'll see what comes next.

 

this little guy could be in there

 

You could hang it next to the bell---

 

Ha! You guys are funny.

So I've had some success tonight. Getting about 10mm (sorry, metric here in Aus) of movement which is very encouraging. The outer pistons are just slightly before TDC so it will be interesting to see how they free up. I'm one very happy camper!

 

Quarter rotation judging by the movement of the timing plate. It's slow going but I guess that's to be expected? It won't just totally free up in one go or should it?

Would hate to get all this way to discover I've just been munching through a dropped chain guide :-\

 

nope, put some more juice in the holes and work it through, back and forth. trying to rinse any junk away, then keep going for more

 

Thanks Polock, I kept at it and now have an un-seized engine. I was working all weekend on the electricals and thought I'd give the starter a go to bump it over. Very successful!

Rookie error : don't try the starter with 4 cylinders full of ATF/diesel with the spark plugs out. Still cleaning it off the garage ceiling.

 

I was a mechanic for a landscape business for a short period. One day I got a call to go out to a job site, some workers had tipped over a diesel Ditch Witch on an incline and it wouldn't start back up. When I arrived, I found that the motor was locked up- presumably from oil in the top end (they told me it had been on its side for around 30 minutes). So I pulled the diesel injector lines off and had one of the guys bump the starter to pump the oil/fuel out.....

....I have never seen a geyser of oil and fuel like that any where else in my life. It was like an oil well erupting. I, along with the three guys standing near me, were all showered. As well as the truck, and my toolbox haha. Lesson learned!

 

Be thankful that you had the plugs out. You could have bent a connecting rod instead.

 

Must be fun to see a bit of movement I'm in the same process as you, was given a '82 650 with a seized engine. It's my first bike and first time working on a bike, did you pour the diesel through the spark plug holes? And did you get your movement by turning the crankshaft bolt?

 

Yes, pull the spark plugs and load the cylinders up with diesel. I use an oversized syringe and tubing from an auto parts store to do it. Hopefully you notice it draining but regardless, put the bike in a high gear (4 or 5) and rock it back and forth regularly. Get 1mm of movement and hopefully that moves to 10mm after a week or so. I had to remove the head and knock the pistons lightly with a rubber mallet and a block of wood to just get some movement into the pistons. Also tried a heat gun on the block and had a 50/50 mix of acetone and automatic transmission fluid (ATF) in there.

Good luck buddy. Took 3 weeks of patience for me but now it spins easily on the starter motor.

 

Thanks for the info, I'll take it slowly so I don't break anything.

 

Some bad news with the engine. It all went back together ok (really well actually) but initial dry compression tests are really low in two cylinders. Probably all four to be honest.

So before I pack it up and think about another hobby, I guess I need to eliminate head gasket and valves? Wet compression test and then a "leak test"?

 

Umm... unsticking it is only a means by which to hone the bores and put in new rings if the bores measure out as useable at the standard bore size.
Engines that stuck can only rarely be run after getting freed up.

Sorry that wasn't mentioned earlier (maybe becuse we weren't sure how stuck it was at first).

No need for a leakdown test. The rings are what was stuck to the bores, and it'll be the rings that are not letting the cylinders build compression.

You could take a gamble and see if it'll start and maybe get the rings to seat again, but the risk with that is ending up with a broken ring (if one hasn't rusted through already).

 

What happened between this..

And now

I see no mention of honing the cylinders and replacing the rings that were ground down by the corrosion on the cylinders walls. While I have heard the stories of having an old seized engine fire right up after being freed up. Taking weeks to free up the pistons so the engine turns over is a good indicator that the rings are history.

~Ghost

 

Good call guys - Looks like a rebuild. PO had said that it was running recently (within 2 years) and stored in a shed so I thought I might get lucky.

Thanks again.

 

Maddington wreckers in Perth has an XJ 650 on there web site right now !! Worth a look?
maddingtonmotorcyclewreckers.com

 

W

Wow, good pickup! Just threw them an email. Thanks!

 

Just an educated guess but I would bet the rings are still sized in the pistons.
~Ghost

 

Are you near them or is it a long drive

 

How many times have we heard, or been told similar things? You didn't really believe him, did you? The thing to do is:

EVERY time you get the "it runs perfect/ran yesterday/ never needed any work/huh.......never made thatnoise before/battery was good yesterday/shop went through it/etc....." type of line, you say to yourself," yeeeeaaahh, rrright.......so I'll have to fix that, too---taking some more off before I make my offer".

Dave

 

Nope, she turns over easy as. Both with the starter and the timing bolt and spanner.

 

Not far at all but the guy said he's not sure about the state of the motor. He has already disassembled the bike.

 

...I think I interpreted that as still seized pistons. I agree, the rings might be stuck for sure.

 

Well, that could mean the rings are seized in their grooves, and you have a very low compression.....that would allow it to turn over really easy too

 

Exactly!

~Ghost

 

If the motor is out he can still run the starter and do a compression test

 

True. For a bit of context, I paid $500 (Australian) for this bike, so next to nothing. It's in fantastic condition overall so I'll probably rebuild the motor if it's viable. The wrecker was going to charge $550 for the motor alone if he could turn it over and it looks rough as guts.

I really appreciate everyone's help on this forum. I'm going to take a bit of time away from the bike to work out my next step, but a check of the cylinders and a rehone/rebuild is definitely on the cards.

 

Priced up the rings yet ? They will be close to the 500 (AUS) you already paid I reckon..
I got lucky with some NOS for my 600 a full set (bar one ring) and it still cost 100 GBP.

I take that back - I checked an Chacal does them for 170 USD - a bargain actually.