Seized?

[daveyg]

Hello All, I just got a '80 XS1100 special as part of a multi bike deal, and since it was the best of the 3 I got to work on it, now, it seems like it might be seized, but the weirdest I've ever seen, I got my 17mm box end on the bolt under the stator cover, and I can get it to turn with a small effort about 3/4 of a turn, and then it sticks again, and so i can go back the other way, to the same point, and it sticks again. What are y'all ideas before I tear the head and cylinders off? Also, if I were to go the overbore/rebuild route, how do I get the timing chain off? Do I need some special chain breaker and where would I get one? Also, where can I get overbore pistons/rings for this baby? Thanks for helpin a newb out!

[The Lorax]

Might not be seized, check if the cam chain is intact, you may be running into valves, these are interference engines, so pull the valve cover and see if the chain is there, see if it turns with the motor. you may have some bent valves or something, but it may not be seized. on the other hand, it could be that there's a spun main bearing allowing you to turn the engine a certain amount before stopping, definitely pull the valve cover and see what's going on under there, hopefully it's not as bad as it seems. also, I believe Weisco makes a big bore kit for these. have a nice day and ride safe

[daveyg]

Yeah, I already got the VC off and the chain is intact, as well as the cams moving with the crank, for the 3/4 turn I can move it, that is.

[DGXSER]

Check that the cams are in time with the crank. I believe you use the T mark for timing. If the tensioner was left to go and the chain skipped a tooth or two you could be off and hitting valves as Lorax stated. Possibly bent valves still, maybe even more likely if someone ran the engine out of time.

[trbig]

Pull the outside spark plugs and shine a flashlight into the cylinders. I'm betting you have rusty cylinders holding you up. It wouldn't hurt to pull all the plugs and put a tablespoon or so of oil in each cylinder while working it back and forth.

You won't feel any resistance when you hit valves with the pistons, so I doubt this is it. I was very careful one time and moving slowly... I never felt a thing as I bent several valves turning it by hand. The valves bend very easily.

When you go to rebuild one of these, you simply unbolt the cam caps and sprockets and slide them out from under the cam chain. No need to split the chain unless you're replacing it.


Tod

[randy]

daveyg;

A word of caution. When you get the motor freed up, replace the stator cover before you try cranking it over. There is a main oil galley plug there that is held in place by the stator cover. Run the motor without the stator cover and that plug will pop out shooting oil like a fire hose.

[daveyg]

Ok, thanks for the tips guys! So I can pull the cams out, and then will the chain just slide through as I pull the head and cylinders off? How do I get to the main bearings if it's one of them that's spun causing my issues? Will I just be able to replace the bearings? Or if I have a spun main, am I screwed?

[trbig]

Yes, there's a cam chain galley in the center of the head and cylinders that the chain will drop down into the bottom of the motor. When reassembling, tie a piece of string or something to it and fish that string through the middle of things so that after you get the head on, you can pull the chain back up through.

You'll have to split the cases to get to the main crank bearings. You don't have to remove the cylinders (which can be a MAJOR PITA) to get to them, but if you have spun a bearing, the block will indeed be junk and probably the crank also. If you have spun a bearing, 99.9% of the time it will be one of the outside ones. You can take the side covers off and pull up and down on that rotor or the timing plate. If they have really any play up and down at all... it's bad news. Both the timing plate and the rotor are connected directly to the crank.


Tod

[fredintoon]

Hi Davey,
the XS11 engine bottom end is all shell bearings. The 3/4-turn & stop can be a bad main on a roller & ball engine but on a shell bearing engine a bad main is usually asymptomatic until the engine fires up and you hear the deep booming knock. I'd suggest pulling all 4 plugs, dosing each cylinder with penetrating oil and letting it sit overnight. Next day put the bike in high gear and shove it back and forth to see if the engine frees up.
BTW, if you are new to XS11s you may not have noticed, the engine runs backwards.

[daveyg]

Hi Davey,
the XS11 engine bottom end is all shell bearings. The 3/4-turn & stop can be a bad main on a roller & ball engine but on a shell bearing engine a bad main is usually asymptomatic until the engine fires up and you hear the deep booming knock. I'd suggest pulling all 4 plugs, dosing each cylinder with penetrating oil and letting it sit overnight. Next day put the bike in high gear and shove it back and forth to see if the engine frees up.
BTW, if you are new to XS11s you may not have noticed, the engine runs backwards.

Well, that's good news about the bearings, I'll try the penetrating oil idea, what brand/type would you recommend? PB blaster or what? Thanks a bunch, and I caught the backwards engine thing on someone else's thread. Thanks again!

[trbig]

I'd use penetrating oil if it was indeed stuck... but in your case, I'd just use regular oil to get it slicked up. Just my opinion though. I'd definately look down into those cylinders though and see what I could find.

Good luck.

Tod

[DiverRay]

A good alternative to PB Blaster is to put some Automatic transmission fluid in each hole. It has anti foam, and ANT-RUST additives, so it makes for a good first choice. Fill all 4 pistons via the spark plugs, leave for at least 24 hours, and then try turning over with the plugs still out. It WILL be messy, but should free things up if it's rust causing the problem.

[wa407mpp]

While you have the plugs out look into the cylinders for objects a po may have dropped in and forgot about. It could be a broken rod I've seen them break at idle and jamb up an engine just in that way. What ever you do don't try to strongarm it or you may break something expensive or irreplaceable, even if you have to tear it all the way down.

[daveyg]

Ok, I filled 'er up with ATF... and she soaks... If that don't work, I'll start the teardown and keep you guys updated.

[daveyg]

Ok, so whatever is causing the holdup is still there, so it apparently isn't rust because the ATF would've made quick work of that, and the red geyser was pretty neat, by the way... I ended up draping an old rag over the top of the bike, with one underneath, to keep it from spraying the roof of my truck, that the bike is in the back of... Anyways, looks like I'll be ripping the head off tomorrow, and follow that with the cylinder block, if it's not something in the head, like a bent valve causing my issues... And while I'm at it, thought i'd ask what benefits, if any, can I gain by porting the head? Will it net me any extra ponies? Would I need to bore the carbs too or do they flow pretty well? Thanks guys! I'll post pics of the culprit when I find him... And I'm keeping my fingers crossed that it's not a broken rod...