broken engine!! :(

well it happened just like bigfitz said it could, fortunately it wasnt anything that i actually did wrong but just a freak accident. while replacing the valve shims, i kept forgetting where i put the tools i was using, so i laid a shop rag over the bike to put the tools on, as i did this i somehow crossed fuses and the bike engines turned over (the keys wasnt even in it!) for the split second that it turned over i heard a crack and something go flying the thing that went flying was the shim removing tool attached to a piece of my engine! as i realized what had happened i started screaming in disbelief and crying :cry: ... i was so close, SO CLOSE!! to having the bike running! and now this, i have no idea what to do now, im sure a new engine head is not cheap and im sure i cant afford it no matter what the price. my whole dream just shattered along with my engine. i really needed this bike to be running and soon and now this... so now im not sure if i should try and find a replacement part or just part the bike out and hope that i can get enough for it to buy another one? this is just now the worst day ever. is this piece even replaceable? or would i have to take every thing part?! or replace the entire engine? im looking for some sorta ray of hope here but im just not seeing it....

 

OUCH!!!!!!!! Sorry to hear that it broke. Either you can find a new head OR you can pull it and have it welded. I've had it done before aloooooong time ago.

 

You'll need to find another cylinder head; or another engine. Either way, it won't be quick, cheap or easy. But it is totally do-able.

This is why it's important to disconnect the battery when doing any work on the bike that involves disassembly. Even if it seems unrelated.

I realize that's no consolation at this point; hopefully it's a lesson for other owners who are getting started doing their own work. If it's any help, don't feel too bad; you're the second member in a month that's broken his cylinder head with the valve adjustment tool.

 

man that sucks. I thought my situation was bad.. Spent all winter restoring my bike. I just put new tires, new paint job, new hard saddles bags on my bike. Then the engine let loose the first day I rode it. I to am looking for motor.

 

Here is a head for a good price.
http://www.ebay.com/itm/1981-Yamaha-Max ... 6f&vxp=mtr

I have never disconnected the battery when working on the bike. I think I will start doing that now.

 

Yet another reason why I prefer the Zip Tie method instead of that lousy tool.....

Try JB weld and Duct Tape. If anything can fix it, they will

 

fitz maybe your should edit your write up on shims and put a warning in there to disconnect the battery. (even though yes it should be obvious and i dont know why i didnt do it as i normally do)

ok now i need a nod of approval on this ebay listing.... does it look okay? its a lot cheaper than i expected so im thinking about buying it... what do you think? http://www.ebay.com/itm/1981-Yamaha-Max ... 6f&vxp=mtr

 

Damn, what a bummer! Sorry, man!

Looks like that ebay listing already ended.. maybe this one?

http://www.ebay.com/itm/1981-Yamaha-XJ5 ... 5075wt_746

Hit me up if ya' need a hand with anything.

 

Hell, yeah. Do it.
You can have the valves ground while it's off and get your valves all shimmed up before you install it, have it media-blasted with walnut shells, replace guides and seals while you're at it. You will be in better shape than you were last night.

 

it ended because i bought it, lol . now how do i get this beast off there, aka how do i get the chain off?

 

Not to mention you will have a bunch of spare parts such as valves, shims, springs, cams........

 

Good on you!

 

THAT ONE! (The second one.) http://www.ebay.com/itm/1981-Yamaha-XJ5 ... 4118wt_928 It comes with the camshafts (a concern when shopping for a used head.)

I've found that pre-owned heads often go for cheap. I got my spare, with camshafts, cam chain tensioner bits AND valve cover for $10+ shipping.

You want to try to find one complete with cams; so you don't have to worry about journal bearing clearances.

 

AHEM.

Got your manual yet? You DON'T "get the chain off." It stays behind, and hopefully stays engaged with the crankshaft. The sprockets come off the cams which then slip out, leaving the chain in place.

There is a lot more to it than I've described. DO NOT try to pull the head without benefit of a service manual.

 

Shame you're on the other side of the pond or you could have had one of my spare ones.

 

ok chain stays got it, ill give my manual a read through (why didnt i think of that...)

 

OK so i did it! the head is off! all in all it wasn't that bad. i wish i didn't have to do it in the first place but well.... yah.

here is it with the head off.

and here it is next to my exhaust on the garage floor. my finger is pointing the the piece that broke off.


now i plan on ordering a new gasket, and all. new hardware. is there anything that i can do in the mean time to kinda clean up this area, as i does need some cleaning. there seems to be a bit of build up on the piston heads, what the best way to remove it, with out being to invasive?

 

WHERE IS THE CAM CHAIN? It should be sticking up out of the crankcase, hanging from something...

The BEST way to clean up the tops of the pistons, etc., is with your shop vac. That way you're not breaking loose a bunch of crud to get into the gaps between the pistons and the cylinder walls.

TIP*** Stuff a rag into the cam chain gallery so a stray nut or bolt doesn't end up down in the motor.***

You'll want new valve stem seals too; and take the "new" head somewhere to have the valves lapped, the "flatness" checked, and the new seals installed.

I'll be adding a line or two to the valve clearance "how to."

 

the chain is there its kinda flopped over the front of the motor, it blends in with the frame.

and i will definitely put a rag in there thank for the tip!

 

I don't know how close the upper engine is to a 650 but if there are tall rubber grommets (they aren't rubber but more of an elastic material) that sit between the very right vertical steel dowels, don't forget to replace them.

Also, if there are two flat copper washers on the right hand side of the engine head where the chrome oval nuts tighten down onto the vertical steel dowels, replace those.

I know it from experience on my 650. I've had the head off several times because of little things like that I missed. The critical one is those tall elastic o-rings I mentioned in the first paragraph. If you don't replace them with new engine head gasket, trust me you'll have oil start to seep and mist across your legs in the hot summer time. Of course, this is all on a 650 maxim so I don't know how closely related these tips are for ya. Just giving you some experience..

 

It could be worse!
You could be from Moore, Oklahoma.

I've seen 'em all now.

 

Why would being from Moore Ok make it worse?

 

Probably because of the tornado today: http://www.huffingtonpost.com/2013/05/2 ... 09844.html

 

Sucks for sure but it looks like you're on track.

Get your valves lapped and new valve stem seals while you're at it.

Also, disconnecting your batt ( pulling off the neg. wire) is a good idea, also take this time to upgrade the old glass tube fuse box with a new blade style box that has a cover. Then you won't jump a fuse if you lay a wrench accross it by accident.

Lessons learned, it will all work out fine.

 

Perhaps this will enlighten you:

The Tornado's Path

 

you'll want to keep that cam chain tied up instead of flopped-keep tension on it. I would stuff lint-free rags anywhere you can when you go to clean. Take your time and be careful. On the plus side your engine looks clean and once your done will have a head that is practically new.

That is the second time in less than 15 years that Moore has been nailed by a monster tornado. If you lived there your XJ would be crumbled up tin foil by now! Personally I wouldn't rebuild there unless it was a 10inch reinforced concrete home from top to bottom.

 

Damn Raven sorry to see all of this. If you need a hand working on it let me know. I sent you a PM the other day with my number.

 

ok so i was checking out new head gaskets and they are way more money then i expected, i clearly need a new one, but i wonder if there is a way to refurbish the one i have? it seems to have 3 layers, 2 rubber/sticky layers and a metal type layer in between. is there a way to just replace the rubber parts seeing as my metal is still in good shape? i think the cheapest gasket i found was around $50-60! any ideas? and whats the best way to remove some of the older gasket pieces that are stuck on?

tat2demon ill keep it in mind thanks!

 

The head gasket is an ASSEMBLY the "layers" aren't independently replaceable. And no, they're not cheap, unfortunately. Check with XJ4Ever, you're going to need some o-rings and other bits with it.

Gasket remover (be careful it removes PAINT) or lacquer thinner and a suitable scraper. Be careful that whaever you use as a scraper doesn't gouge up the gasket surfaces in the process.

 

I'd also advise taking your time, and being OCD about organizing all the parts you uninstall and/or will have to reinstall. The manual is a must; I'm assuming you have one by now. And if something doesn't fit right, stop, think, take a break if you have to; something's probably out of position somewhere.

That said, this is obviously something you can totally do on your own.

If you want something to clean, how about that exhaust?

 

Have you looked into an entire engine gasket kit? Theyre just a bit more than the head gasket is by itself but then youll have everything else if/when you need it later down the road.

Being that youre putting on the new head, it would be a good idea to not only lap the valves but if you have the gasket kit you could also change the valve seals. You would also have a new valve cover gasket that way.

Separately I think the head gasket, valve cover and valve seals already put you over the cost of the entire kit.

 

i did see a few good prices on the kits, and figured that would be the way to go, better to replace them all now then replace one and have to take it all apart to change something another time. but i always look for options, especially if they save me money. i just want to make sure its done correctly as well.

thanks everyone

 

got my new valve cyclinder head, its in decent shape just gotta clean it up a bit (carn cleaner? brake cleaner? gasoline?) as it appears to have been off bike for a bit. also got all of the old gasket pieces off the motor, still waiting for the whole gasket kit to arrive (its coming from japan off ebay, got a great deal on it). quick question once i get everything back together im guessing i have to remeasure for the valve clearnences and redo the shims. but should i rotate the engine a bit to get everything moving and in place? or just put it together and mesaure the clearences?

also i cleaned up the bottom of my il pan the the exhaust today as well, still could use another good srubbing, but its much better than what it was this morning. on the topic of exhaust on the new valve head i noticed that two of the bolts that hold the exhaust on are missing, but it looks like i can screw in new ones, i tried getting the one off of the old head but they were pretty stubborn even with vice grips. would it be easier to just get new ones? and could i find a double threaded bolt like that at a hardware store?

 

NO NO NO NONONONO!!!

That head needs to be taken apart, the valves lapped and the valve stem seals replaced UNLESS YOU WANT TO GO THROUGH THIS AGAIN IN A COUPLE THOUSAND MILES.

DO NOT just "clean it up with some carb cleaner" and throw it back on. All you'll be doing is throwing away the money you spend on new gaskets when you have to pull it back down because you've got a couple of leaky valve stem seals.

You say you want to do it right but you continue to look for shortcuts. NO you won't find proper replacement exhaust studs at the hardware store. Get REAL ones, good ones; check with Len or on the aftermarket.

***TIP*** Forget about the hardware store. We're not fixing appliances, we're working on motor vehicles here. You go to an AUTO PARTS store; a good NAPA is a goldmine of cool old-school stuff. If it has a creaky wooden floor, you know you're in the right place.***

UNFORTUNATELY, Yamaha (and the Japs in general) used thread pitches that often aren't commonly available. Pretty much anything that screws into the motor will be a "not corner store" item.

Let me give you a tip that applies to this entire process:

DO IT RIGHT THE FIRST TIME OR YOU WILL BE DOING IT AGAIN. Any money spent on "shortcuts" will have to be spent again PLUS the cost of the stuff you thought you were saving money on when it turns out you have to do it again.

Slap that pre-owned head on it without doing a proper valve job and you'll just be wasting the money you spend on the gasket set. On the upside, you'll get a lot of practice pulling the head.

The downside is all the time spent fighting with this instead of riding the bike. We haven't even gotten to the brakes yet.

Understand something:

You've already broken the motor by not heeding advice given. We just don't want to see you keep screwing yourself up; right now you're your own worst enemy.

 

Forgot something: If you're not familiar with lapping valves, valve spring compressors, valve stem seals, etc; just take the head (with a new set of valve stem seals) to any COMPETENT automotive machine shop; they do valve jobs all day everyday. Ask your local "big box" motorcycle dealer who they "farm their heads out to." Or ask the guys at the previously recommended NAPA for a reference to a shop that does small-displacement multi-valve heads. Any place that can do a valve job on a 2L Ford ZETEC head can do an XJ. But they'll need the new valve stem seals.

It's not expensive, BTW. A shop that actually knows their stuff won't charge you over maybe $100. And quite honestly; even though I have a set of valve-lapping "cups" and lapping compound, and a seat cutter and the whole nine yards--- I'd just take the head someplace and have it done too. A pro will knock it out in no time and it will be right.

 

Fitz while appreciat your advice and knoweldge, i think you need to step down a bit, on the cleaning i was reffering to the exterior shell of the head, the grease and grime. and excuse me if i said hardware store i constanly referre to autozone type stores as hardware stores because, well nuts and botls are hardware. and im not looking for short cuts, im looking to save time waiting for parts to arrive in the mail if i can go to the AUTO PARTS store and pick it up. and the motor breaking was not because i was trying to take short cuts or didnt read the advice given, it was a complete freak accident that im sure no one couldve forseen. I am trying to do it right and that is why i am asking on here, (unfortunatly my service manual isnt much for conversation). i planned on lapping the valves and that is what i was getting at by having to remeasure the clearences, aka what did i need to do to make it right; sorry if i dont know the correct lingo (lapping). i never said i was gunna slap ot on and hit the road. please put your self back to when you started working on bikes, im trying to learn and you yelling at me and saying that im just gunna mess everything up isnt doing much for my confidence. you can write a responce with out sounding so negative. "more flys with honey"

 

I'm not being negative. It sounded to me like you were going to re-install the head without first disassembling it to lap the valves and replace the valve stem seals. My apologies if that was not the case.

If you do lap the valves, then of course you'll need to re-check the clearances since you'll be removing metal and putting them a few thousandths deeper into their seats.

That's why I posted the advice about taking the head in; I would and I've lapped a few zillion valves in my day.

If you do it yourself, pay attention to the orientation of the valve springs; the inner and outer springs "rotate" in different directions and have to be re-installed the same way they came out.

The Clymer manual covers the whole valve job procedure on pages 83 ~ 87; valve lapping is on page 87, that's pretty much the final stage in the whole process.

The sticks with the suction-cup ends and valve grinding compound are available at most good auto parts stores. Be careful on the suction cup tool that the one you get is small enough. XJ550s have tiny valves compared to Ford V8s.

 

Just saw this thread for the first time. That really sucks Josh. :cry: At least you're on the right track to getting it back together again.

Just to reiterate what others have said, take your time and do it right so you don't have to do it over again ( not trying to insinuate that you're not doing it right, just a reminder ). Hang in there!

 

Josh, not trying to sound like Donny Downer here, but Fitz's point(s) are well-taken.
I've been wrenching on bikes and cars for over four decades and have been wrenching on aircraft as a profession for over three decades. That being said, I will throw my .02 in......
Take your new head to a good machine shop, as was mentioned. a good bike machine shop would be best, but any good automotive machine should should suffice. Have the following work performed:
a) Valves ground and lapped
b) Valve guides measured and replaced as needed
c) Valve seals replaced
d) Valve shims installed for clearance
If budget and time allows;
e) Head hot tanked and de-greased (it will look friggin' brand-new!)
f) Head checked for true...many times a loose head will warp and twist over time
g) Cams inspected and plasti-gauged for fit (you are reusing your old cams in the new head, right?

This work alone may cost you more than you anticipated, but reason with me here....if done correctly, your head will give you many, many miles of trouble-free use before you even need to check valve lash again.

While you are saving up your pocket change for the machine shop, some other things you can do are:
1) Using a scraper made from a piece of plexiglass, you can put each piston at TDC and scrape off the carbon using ScotchBrite as a chaser. Vacuum the loose carbon with a shop vac before moving on to the next piston dome.
2) When finished with all four, put each piston at BDC and wipe the cylinder wall with a clean rag lightly oiled with an appropriate bike oil. Make sure your cam chain is adequately supported throughout the entire operation.
3) Use this opportunity to mic out your cylinder wear (comparing BDC readings to TDC readings. Because if you need a ring job, there was never a better time....
It's also advisable to make a few aluminum tubing sleeves to slide over the head studs and thread down the cylinder head acorn nuts to keep the piston movement from breaking the seal on the cylinder base gasket.
Understand that we are trying to prevent you having to re-do anything and it's with the best intentions......

 

The bolded sections are things you can do yourself with the right tools and patience. If you aren't confident or don't want to put in substantial time, go machine shop route for all of it. But some of it is really pretty easy like the lapping, seals, checking for true, and plasti-gauging. Obviously the other things can be done by a home mech, but they are way harder and require more skill & tools.

A good machine shop is better if you go and talk to them first, you can seek out advice on a good one, but my experience is call around and see which one seems interested in the work. Go see them, talk slow, and be nice-i.e. don't act like you need this done 'now' or your pushing - just try and get in their good graces and I promise you will get your work done right and reasonable. Most of these guys love to work on motorcycle parts as more than half the time they are dealing with much more cumbersome parts.

Don't get discouraged or take any advice personally. It's just love of motorcycles and experience that makes it sound negative. Just use what information you receive to your benefit and forget the rest. After all it really is all meant with the best intentions. And no doubt once it is all done you will have one very nice and practically new XJ head.

 

is grinding the valves the same thing as lapping? 2 of the shops i called seemed confused when i said lapping.

 

A machine shop should not be confused by this. Lapping is the finishing step, done by hand with the little suction cups on a stick fitz mentioned and lapping compound is used as the abrasive. You basically turn the stick attached to the valve (in its seat) rapidly between your two palms.

Grinding is done on a machine and it will take away far more material than lapping. grinding would be the first step, if needed.

 

I'll annoy everyone by suggesting that plasti-gauging the cams is not going to help you much. I thought you said that you had a set of cams with the new head, so you should use that as the parts will be worn in to each other. If the oil supply hasn't failed then the cams will be good enough. If the supply has failed then you will see the damage visibly.

The reason I say to skip it is this - you use plasti-gauge to check your crankshaft main bearings. Yamaha had a range of sizes that they ground their cranks to (presumably coping with worn machine tools and allowing for errors first time around) and there are shell bearing inserts that vary in thickness (just like the shims). You use the plasti-gauge to check the clearance to find the right shell thickness to use to get the right oil gap.

The camshaft bearings are line bored and the shafts run straight in the heads with only the oil to protect them. If the plasti-gauge says that the gap is too big the only option would be to throw it away. Unless you can see deep grooves (and even if you have deep grooves, you can still use them if you have no replacement, though I wouldn't buy the gasket kit to rebuild such an engine - I'd save that for when I had new bits) then the head and cams are okay to use.

If you are going to use the plasti-gauge anyway, do it first, before spending on anything else though.

 

You are not annoying me! While you are correct that there is little that can be done with a too-large gap, a too-small gap is more critical and can & will cause cam seizure and possible total engine failure. This can be corrected before engine assembly by align-boring, which is why I brought it up. And I believe he said he bought the head without the cams, though I could be wrong...

 

both cutting new angles on the valve and grinding the valve seat will change the shim size. hand lapping not so much. depending on your shim sizes now you may run out of sizes.
valve guides take specialized reamers that ain't cheap so if you go that route your going to pay for a little more, unless the shop already has them. do they even make valve guides for these ?
i think your best bet is hand lap the valves and put on some valve stem seals and call it a day

 

Good point. But we are advising him on how to install the head for minimal maintenance in the future, right?
Yes, the valve clearances may have to be adjusted now, but that should cover it for a long time.
On the other hand, I've gotten great results by hand-lapping using only thumb pressure on the valve and a piece of rubber tubing slid over the (unsprung) valve stem with good high-quality valve lapping compound. The proof is in the grey line left after lapping on both valve face & seat. Nice, wide even grey line indicates a good seal. You can check your results by filling the chamber with stoddard solvent and checking for leakage past the (unsprung) valve.

 

Unless the valve are burned I would not worry about grinding them. just lap them replace the seals and check the the head for warpage. Also check the cam bearings (first by the way) for any scoring. If they are scored bad the head is trashed.

As for hardware stores,,, I have never found any problem getting the proper bits and pieces for my bike. As a mater a fact I have better luck there than where I work at,,,,AUTOZONE. But those studs will be a specialty item that would not be at either place. Try Len, our online parts guru.

 

ok so i just got my gasket kit (which came really fast! even from Japan) and i recognize a lot of the gaskets that are there, clearly the head gasket and valve cover, and im guessing the larger round one is the clutch cover. but there are some that im just not too sure about where they and im wondering if there are any that i should give to the shop when i get my valves lapped?

these are the one i am unsure about.
the large square one (oil pan?)
there are 4 of the round copper color ones, what are they?
the 8 tall green ones?
there are 4 of the flat round one with with little wings (intake?)
the 2 tall black rubber one those i recognize from under the head.
the 4 large rubber o-rings?
all of the other small o-rings, 2 red ones, 2 larger one and 2 really small ones?
and the 2 (green and grey) flat gaskets?

let me know what i have here, unfortunately it didnt come with instructions or a contents list. still calling around to find some one to do the lapping

 

The 8 green ones are the valve seals, the ones with the wings are intake boots, guessing the coppers are crush washers for your fill and drain plugs? Round ones should be timing cover and clutch I think. No idea on the o-rings. Square should be oil pan.