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xs650 > > Motorcycle Systems > > Engine > > Trying to change leaking head gasket.


Trying to change leaking head gasket.
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yamakofu
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PostPosted: November 16, 2009, 1:15 am    Post subject: Trying to change leaking head gasket.

I have a 79 xs650f which has been stored for around 5 years. I cleaned the carbs out (one was pretty clogged) and got the bike running with new oil and plugs. Then, just recently, I have replaced the points system with Pamco ignition.

In order to remedy a long standing oil leak problem, I decided to replace the head gasket.
I have the engine out and am stuck unable to remove the centifical advance adjust unit and the housing with the three screws.
1. I am not sure how the centrifical unit comes off.
2. The three screws that hold the housing are really on tight, and one of the screws is damaged and looks hard to get a bite to turn.

I have chosen to wd40 the screws wait overnight and post for the first time here on 650 rider.
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nj1639
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PostPosted: November 16, 2009, 7:04 am    Post subject: Re: Trying to change leaking head gasket.

That's where the impact screw driver and proper bit is MOST NEEDED if nowhere else. They are a bear.
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yamakofu
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PostPosted: November 16, 2009, 12:36 pm    Post subject: Re: Trying to change leaking head gasket.

Right, I looked into mikesxs and saw that there is an impact driver available for $19.00 with the tag:
"Impact Screwdriver with bit set in case. A must have tool used to break loose engine screws with slot or phillips heads."
sure nuff.
Thanks for the quick reply, nj1639, I just may place an order for one.
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yamakofu
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PostPosted: November 16, 2009, 3:16 pm    Post subject: Re: Trying to change leaking head gasket.

the overnight wd40 may have just done enough where I was able to remove the three screws by tapping a phillips bit and turning it with a 8mm wrench.
I am still not sure of the removal of the sprocket like nut, is it? that seems to be holding the centifical advance weights' unit... considering tapping the notches with a standard driver hmmm.
and uh, just sprayed wd40 on the points side housing to let it soak in...to remove those three screws, also rather tight.
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yamakofu
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PostPosted: November 16, 2009, 9:30 pm    Post subject: Re: Trying to change leaking head gasket.

managed to get the three screws off from the points housing as well.
now, still wondering how to get the sprocket like part off the right side.
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dpmphoto
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PostPosted: November 16, 2009, 9:41 pm    Post subject: Re: Trying to change leaking head gasket.

its threaded and u should be able to tap it off by putting a screwdriver in one of the slots and tapping it counterclockwise until its' loose and then u should be able to turn by hand.As long as your doing the head gasket you might as well port it replace the cam chain guide if need be et. Really should get a shop manual especially when you go to put the cam and cam chain back on otherwise you might have a bike that wont start.Just my 2 cents
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yamakofu
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PostPosted: November 17, 2009, 2:43 am    Post subject: Re: Trying to change leaking head gasket.

thanks dpmphoto I thought tapping with a standard screw driver may do it, but since it didn't easily turn, I thought I'd let is be till I got a more info, and that would be you... I had a Haynes, but it has been misplaced but I think it will turn up somewhere someday. meanwhile I am grateful for all the informations available here. I will try it tomorrow. When I remove the cam, I intend to mark the sprocket and chain link to return it in the same position. And to not let the chain get slack by tying it and keeping a tension to maintain its lower positioning... I will halt the project to order parts when I find a need for example chain guide. I am anxious to see the valves, I may ask around for a shop which may port. I don't have all these tools, but it may be a chance to get them and learn...depends on how much the port job may be (any ideas how much?)
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despecial
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PostPosted: November 17, 2009, 8:51 am    Post subject: Re: Trying to change leaking head gasket.

manual
-all in english

XS650 Models 78-80 - (11616-XS-61) www.biker.net


...service point chart...
www.xs650.de/literatur...points.gif

...motor breakdown overview...
www.xs650.de/literatur...engine.gif

...manual for XS650E including later supplements - in english

www.xs650.de/literatur...-intro.pdf ...introduction

www.xs650.de/literatur...artung.pdf ...maintenance

www.xs650.de/literatur...-motor.pdf ...motor

www.xs650.de/literatur...rgaser.pdf ...carb

www.xs650.de/literatur...hrwerk.pdf ...frame

www.xs650.de/literatur...ektrik.pdf ...electrics

www.xs650.de/literatur...ektrik.pdf ...electrics

www.xs650.de/literatur...ung-se.pdf ...supplement SE

www.xs650.de/literatur...zung-e.pdf ...supplement E

www.xs650.de/literatur...ng-se2.pdf ...supplement SE II

www.xs650.de/literatur...g-sf2f.pdf ...supplement SF II/F

www.xs650.de/literatur...ng-gsg.pdf ...supplement SG/G

www.xs650.de/literatur...ng-hsh.pdf ..supplement SH/H

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yamakofu
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PostPosted: November 17, 2009, 12:20 pm    Post subject: Re: Trying to change leaking head gasket.

thanks despecial, i have the carbs appart and have noted my jets are 140 and 30 for the pilots. The specs you provided tell me the stocks were 135 and 27.5. I am cleaning the carbs again since one of the new spark plugs got pretty black right off installing the new Pamco sytem. NOT the pamco's fault at all. I was thinking that maybe one of the original coils was beginning to fail since it seemed like there was a stumble... so with new single coil plugs and wires, and pamco ignition, I am re-examining the carbs which I would have liked to blow out with air (compressor) but it is unavailable and I blew out what I could with my mouth... but this is a different topic... which i may post after checking to see if the problem disappears. (last carb note, both mixture screws' orings have a split in them and I am waiting carb kit from mikesxs) ... oh and of course coming back to the head gasket, I am thinking the leak is affecting the spark plug's blackness.... opinions?
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yamakofu
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PostPosted: November 17, 2009, 12:22 pm    Post subject: Re: Trying to change leaking head gasket.

Note: regarding jets, carbs had K&N filters and exhaust is 2 in 1.
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yamakofu
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PostPosted: November 17, 2009, 10:42 pm    Post subject: Re: Trying to change leaking head gasket.

OK I got the top of the engine off, exposing the cam... I read about moving the bearings out will allow the cam to slide out... will look around for that post for now. I wonder do I loosen the cam chain tensioner ...
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yamakofu
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PostPosted: November 17, 2009, 10:44 pm    Post subject: Re: Trying to change leaking head gasket.

oh yeah, check despecial's manual pdf...
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yamakofu
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PostPosted: November 19, 2009, 6:04 pm    Post subject: Re: Trying to change leaking head gasket.

OK I have the top end off here is a web page of what it looks like:

web.me.com/yamakofu/he...moved.html

I am now thinking whether to take the cylinders off or not (I would at least need to get 2 ring compressors wouldn't I?) To replace the base gasket while I have come this far... I am thinking of replacing the rings, mmm and honing the cylinder... to have a shop do this along with cleaning the valves and seats...I don't have the tools.
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yamaman
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PostPosted: November 19, 2009, 6:25 pm    Post subject: Re: Trying to change leaking head gasket.

Well it's up to you, I guess you don't have a compression reading on this motor? If it had good compression say 125psi +, you could very carefuly remove enough piston to get at the gudgeons, remove the gudgeons & leave the pistons in the bore. Same for reassembly, either with pistons left in place, or if you remove the pistons, set them up like this first anyway.

Tilt the motor forwards so your not fighting gravity. Some kind sole might take the time to find retiredgentlemans pics on this subject.

You only replace rings if they are out of spec, so remove the pistons, measure rings & go from there. If the rings are way out, or there is any scoring or major wear, then take the pistons & pots to a engineer for measurment.

Cheers

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yamakofu
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PostPosted: November 19, 2009, 6:47 pm    Post subject: Re: Trying to change leaking head gasket.

just what I needed to hear, thanks. I don't have a compression guage and did not know the compression, but I am betting it is adequate. I will try looking through retiredgentleman's posts as well.
any opinions on getting the carbon off the cylinder tops? brass wire brush? and brake parts cleaner?


also wish for feedback on the uneven carbon of the two cylinders the right is sootier... I am guessing it is a carb thing and am cleaning it again.
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yamakofu
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PostPosted: November 20, 2009, 2:15 am    Post subject: Re: Trying to change leaking head gasket.

thanks yamaman I went ahead and pulled off the cylinders with the pistons in them... I came across retiredgentleman's
www.650rider.com/index...sc&start=0
and will see what I can pick up from it...
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yamakofu
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PostPosted: November 20, 2009, 6:02 am    Post subject: Re: Trying to change leaking head gasket.

a post by 5twins from the link mentioned in the last post:

"For cleaning the carbon off, I use paint stripper. Paint it on, let it sit 10 minutes or so, and wipe it off. Several applications may be needed but it will literally melt away most of the carbon. What's left will be softened and can be easily scraped off. This also works well for gasket removal. Clean the carbon off the heads and test the valves for leaks before you disassemble them.

When you get to the re-assembly part, read over the "Leakless XS Assembly" thread over at the Garage, there's some good tips in there. In particular, adding a small bead of sealer to the head gasket around the cam chain tunnel and 4 outer oil flowing stud holes. This is just some added insurance against the problem David encountered."


I don't have paint stripper, but am contemplating oven cleaner, I'll give it a try in safe areas, and follow up with brake parts cleaner.
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benztech
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PostPosted: December 3, 2009, 11:47 pm    Post subject: Re: Trying to change leaking head gasket.

for carbon removal go to NAPA and get a can of SEA FOAM. it will dissolve the carbon to nothing... super great stuff and it's very cheap.
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yamakofu
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PostPosted: December 4, 2009, 3:31 am    Post subject: Re: Trying to change leaking head gasket.

thanks benztech, I've got to look into that stuff... I have scraped off much of the carbon with a metal pot scrubber mesh... and some bamboo chop sticks' back, flat end as well as ... brass and metal wire brushes... pretty much experimenting to see what removes without scratching... the mesh pot scrubber was rather efficient... the oven cleaner did almost nothing... I am at this point debating whether to buy a valve spring compressor or to find someone to loan me one some how... otherwise, the cylinder is painted black on the outside and back on the case with the new base gasket. the valves seemed ok , but I am just waiting for some opportunity to lap the valves... before installing the new head gasket and top of the engine...

and for anyone keeping track of a side issue of one spark plug getting noticeably more carbon on a pair of fresh plugs and newly installed Pamco ignition, the culprit seems to be a hole in one of the carbs floats... (one of the floats was partially filled with gas) so the one carb was getting more gas that it should have I am guessing.

I used small amount of JB weld to seal the pin hole size hole in the brass float for the time being, to replace with something better when the opportunity allows.

I will post picts and a link for the page when I compile enough images.
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yamakofu
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PostPosted: December 4, 2009, 3:55 am    Post subject: Re: Trying to change leaking head gasket.

mmm a little revision / update...
I have managed to remove the cam by sliding it under the cam chain, not having to cut it, by removing the cam bearings (even just on one side)
which allowed enough slack. thanks to forum tip. the Haynes manual which turned up by the way, as many other sources, say to cut the chain, but it seems a waste.

Now, the cam chain guide is worn with the plastic kind of coming off, so I am waiting a Mikesxs shipment for this... (adjuster is ok)

Earlier, I posted, I will mark the chain and sprocket and wire the chain to keep from loosing its location on the crank sprocket... I was a bit naive there...
so now, I will feel for top dead center with the head still off and notice it at the first notch on the timing markers... then with the front of the timing chain taught, without slack, I plan to use the notches on the cam that indicate it is in the top dead center position... on top ...That is what I am planning on for the moment ...
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despecial
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PostPosted: December 4, 2009, 4:23 am    Post subject: Re: Trying to change leaking head gasket.

- just beware that there are 2 TDCs each complete firing cycle...this is because although the pistons rise and fall together only 1 cylinder fires each time

- the easiest way to determine which cylinder is firing is with the engine complete...find TDC and wiggle the rockers, the cylinder with both rockers free is on the firing stroke

- brass floats can be soldered

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yamakofu
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PostPosted: December 4, 2009, 4:49 pm    Post subject: Re: Trying to change leaking head gasket.

oh yeah soldering iron, I could do that...

eanwhile, since I now have the Pamco ignition, with one coil firing both plugs every cycle, with one side's firing wasted each cycle, I am wondering... well I will think it over... let's see, is it the cam goes round once for every two crank cycles or twice for every one crank cycle...
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yamakofu
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PostPosted: December 15, 2009, 12:57 am    Post subject: Re: Trying to change leaking head gasket.

So finally I have the valves out and... well I will try posting a pict...
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yamakofu
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PostPosted: December 15, 2009, 1:07 am    Post subject: Re: Trying to change leaking head gasket.

to try to sort the situation out, it looks like the one cylinder which was more carbon covered, which I am attributing to the leaking float, had been going on for some time.
some of the seat is detonated away, and I am not sure if cutting the seat is enough or if I should get a used head to replace mine with.

I am now pretty sure that I will get new rings, having been told that when the head gets the much improved seal, blow by will increase past the rings unless replaced, or rather, it is worthwhile doing at this stage.
I will likely get new valves, guides and guide seals... wondering whether to get stainless valves or standard ones.

But right now, I am looking on ebay for used head. Mine is a 79, so I am going to see which years will work with my year...(looks like 70-84)

Oh I should mention, I was hoping to just be able to get away with a lap job, but after the lapping attempt, the condition revealed its damage.
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