HELP!!! I broke it!!! Won't start. Warning LONG!!!

I'm in heavy construction as well, but in the field portion, so I'm always outside. For me, the heat is in the tools, lol. One good thing I do have to say about this business though is the ability to scrounge amazing stuff. I can't believe the good stuff they throw away on these big jobs. I have a little welder and have built numerous little projects over the years, all with steel scrounged off job sites.

When all is right, these are very easy starting and nice running engines. I just pulled mine out the other day for the first time this season. It had been sitting since last November. I put one petcock on Prime to replenish the fuel in the bowls, put the choke on, kicked it twice, and it was running. Like RG, I also have about 8 years on my topend. I probably should have bored it but instead just replaced the rings, cam chain, front guide, and did a valve job. I'm happy with the results and service it's given me. I will bore it the next time I'm in there, probably within the next couple years. I've since acquired enough parts to build a whole 'nother motor so that's my plan. Swap the spare motor in and re-do the original again.
 
5twins....I do mostly light commercial 1-6 million.

You're right.....I could bring enough left over stuff from work to be able to fiddle around for DECADES!!!!! I have PLENTY of angle, threaded rod, unistrut and such.....to much really, but I'm never hurting for a peice.

I'm always willing to learn...and I had to go out anyway so I stopped off at my local cheapo auto parts chain store and picked up some 120 grit grinding paste. :thumbsup: It was sold as some off brand but I see that it's made by Clover....same company that made the tub of 280 I've had for years. Figured the seats/valves could stand another round (now there's a pun) of lapping so I gave it a try. I swear at first it felt like it had boulders in it instead of grit!!!! :yikes: :laugh: :laugh: but it didn't take long for it to lay down and I did all four sets with it, then followed it up with my ole trusty 280.

Lapped%202%20003.jpg


Lapped%202%20006.jpg


Lapped%202%20007.jpg


In the first NASTY photos I took of the valves/seats it does look like there was rust....BUT I got lucky and all it was was carbon and there was no pitting at all. What do they say? Even a blind hog finds an acorn from time to time. :laugh:

I'll drag some K1 home tomorrow after work ( I need a YUK! Smilie) and give it a test....hopefully this part of the job is done for now.

Parts should get here by Tuesday.....I'm pretty much ready and chomping at the bit.

Take care......Gordon in NC
 
kerosene is what I always used too. I always leave it sit for a couple hours and put cardboard under it to tell if it comes out. Gas is thin and you are trying to get the same thickness of oil or close too. Gas is dangerous to handle anyhow. Bad for your skin too.
 
Okay, I'm taking my time since this is my first time inside an XS engine. Parts are here and I'm moving ahead....slowly but still moving. The valves passed "my" leak test. :) Sorry guys, but I gave a lot of thought about using kerosene and I just couldn't do it. I'd rather wake up with my sister in a whore house than to have that stuff around the house. :wink2: So I went with my ole trusty gas. :thumbsup: I've been in the construction industry in one form or the other pretty much all my adult life....except for a few years in the service to our country (graduating high school in 1968 wasn't timed very well) and I've inhaled, swallowed, got covered with just about anything you could think of.....if a little of this stuff they call gas now a days kills me.....I have no regrets and have lived a full and interesting life. :)

Now.....I have a bit of a problem I need some help with. I have the cylinders w/pistons on the cases and I'm ready to install the head......BUT I keep worrying I forgot something :confused: and want to be sure before I take the next step. All I'm going by is the parts manual....and if you've ever worked on BSA's and used their manuals.....you know they can be wrong....a lot of times. (That's my excuse and I'm sticking to it.)

I got the two (2) large o-rings on the cylinder liners.......was there supposed to be o-rings on the 2 locating dowels??? I see them for the head.....but my parts print isn't all that clear and I don't see them on the cylinder to case connection. My parts bike's cylinder is still stuck so I can't look at it.

Help a brother out please......:)

Gordon in NC
1975 XS650B slowly going back together
1975 XS650B pile-o-parts
and a room full of BSA unit singles......mostly in bits and peices.
 
No o-rings on the studs, where the dowels are or anywhere else, at the cylinder base or between the cylinder and head. There are o-rings on the top hat shaped sleeves that fit into the four outside stud holes on the top cover, but if you didn't remove those sleeves then no need for new o-rings. What most of us do is add some thin lines of sealer to the head gasket, actually it's easier to place properly if applied to the cylinder top and head bottom, like so .....

HeadGasketSurfaceSealer.jpg


The 4 outside stud holes drain oil from the topend to the bottom, that's why they get ringed. The cam chain tunnel is prone to leaking into the combustion chambers, so it gets ringed too. The front of the head gasket seems more leak-prone than the other areas, hence the line of sealer across it.
 
Hey, Gordon. No o-rings on the locating dowels.If any resurfacing work is done on cylinder or head, the seating depths of those dowels needs checking, to ensure gasket crush. Without the resurfacing work, look up "leakless xs assembly". Another nit, I like to have the wristpin clip gaps facing up or down. I'm sure you're already familiar with ring orientation...
 
Thanks fellows.....I knew I could count on you guys to set me straight.

TwoMany.....yea, ring end gap orientation I got. :thumbsup:

I got so excited about having the rings on the left piston....I forgot to check and record the end gaps on the right piston and had that puppy in the cylinder before I noticed...no notes/figures for the right piston.:shrug:
Why would a fellow do that? So......out with the piston and off with the rings and start from the begining. :(

Thanks for the circlip (wristpin clip) tip......I do like to hide the gap but really never thought about it. I'll do it UP or DOWN on the XS...thanks

I've read the "leakless" thread a couple of times and printed off the important stuff so I have it in my manual.

5twins I've seen your other photos where you had the sealer on the gasket....and also read where you found having it on the mating surfaces worked better....so you wouldn't miss the surface of the chain tunnel.

Here's what bothers me.......I've been using Hondabond 4 for years and as far as I know it's the same as the old Threebond 1104.....and I see that you guys use Threebond...lord not sure what number it is now, was 1104 then 1194 now it's a different number. What KILLS me is that I only work on one...maybe two engines at a time.....then there's a LONG spell where I don't turn a wrench, or at least where I need that sealer. If you look on the BIG tube...it tells you plain and simple....it's got a 12 month shelf life. So.........if it's something I can take off easily...I'll use the older stuff but for stuff like the XS's head gasket.....I GOTA go buy a new BIG tube or I'll worry myself to death about it. They know we don't use that much at a time....why not sell it in a MUCH smaller tube. I'll go buy a new tube....put the newest used on the shelf and throw the oldest away. :( Now I know somebody will chime in and say they've had and used the same tube for 5 years with no problems....wish I could feel warm and fuzzy about that.

Rant over......gota quit crying and get back to work.

Thanks fellows......Gordon
 
Hondabond 4, Yamabond 4, and the Threebond are all the same stuff. Threebond makes it for Honda and Yamaha. I've actually never had any of the Threebond, only the Honda and Yamaha stuff. I continue to use it until it hardens in the tube which, unfortunately, happens before I get to use it all. I think that may be what the shelf life refers to. It's always continued to work well for me up until I can't get it out of the tube any more.

A reminder, lest you forget ..... the oil baffle that fits up into the head. Many find it laying on the work bench after assembly is complete .....

OilBaffle.jpg
 
The circlip gap placement (up or down, not facing either side) is an old go-kart racing tip. If placed to the side, high RPM operation might compress the clip, allowing it to pop out. Makes sense if you think about it.
 
5twins said:
The circlip gap placement (up or down, not facing either side) is an old go-kart racing tip. If placed to the side, high RPM operation might compress the clip, allowing it to pop out. Makes sense if you think about it.
Click to expand...

Yes, that does make sense.

Got a new tube of Hondabond 4 and it DOESN'T say a thing about shelf life. I just looked at my older tube and it happens to be Yamabond 4 (our local shop is both Honda and Yamaha) and I'm thinking it's over a year old???? The Yamabond has the note about shelf life. We'd need to be sitting around the camp fire for me to tell you the reason I heed those warnings...so I'll spare you this time. :) NOBODY around here sells Threebond and some of the places you go in and ask....and all you get is a blank stare and a "never heard of that" :shrug:

Got all weekend to work on the XS.....should be close to starting it up Sunday if all goes well. :bike:

Take care, Gordon in NC

1975 XS650B back together soon
1975 XS650B pile-o-parts but I'm sure glad I have them here....I've used some already.
and a few BSA unit singles
 
Quick update.....things are going slowly...for several reasons that have nothing to do with the bike. :(

I got the head on and buttoned up today. I have to be honest....I REALLY didn't like dealing with the Yamabond 4 on the head to cylinder deal. For a first timer it was a lot to deal with and I kept thinking the stuff would set up before I got finished...(and it probably did but we'll see how it goes) I got everything ready and started by laying the thin lines of yamabond....that was a pain enough but when it came time to get the cam in place I was a wreck....way to much time had passed even though I had though it all out and had everything sitting there ready to go. I was in such a twist.....that I got the chain one tooth off. Just as soon as I turned it over slowly...I heard the same "tap" I'd heard and read about already and knew what was wrong.....damnit. Off with the rocker cover, out with the cam bearings, slip the chain over one tooth and then clean all that Yamabond off........it wasn't fun being me during all of that.

Good news is this time it worked correctly and IF the head gasket stayed sealed....I'll be okay. :confused:

Now......a confession. After I torqued the head down.(the second time)..I adjusted the valves...I was dying to feel some compression...BUT I adjusted the wrong side first. THAT'S what peanut was talking about :) and I understand it now.

BUT....When I first got the bike I adjusted the valves on the bike BEFORE I started it up and it did run. The next time I did anything to them was when the bike wouldn't run.....that's when I found them out of adjustment...but I think most of that was caused by stuff stuck under the seats.

I now have myself a BIG note in the manual telling where the locating pins need to be for which cylinder's valve adjustment.....oh.....After that, I backed the valves off so I can check the torque tomorrow morning. I haven't measured the compression yet....but it'll blow my finger off the plug hole. :)

I want to get the engine back in the bike tonight....and I'm pretty much ready to do that. Then spend tomorrow putting all the other stuff back on.

Take care...it was a BEAUTIFUL day here in NC.....hope your's was too.

Gordon in NC
 
All in all, a good day, but you're worrying about the wrong things. The Yamabond (or Threebond, or whatever) is semi-hardening. It never gets totally hard. That's the beauty of it and probably why it's recommended. It really doesn't matter how long you take for the re-assembly, it'll still be fine. Well, maybe waiting a year or two wouldn't be good, lol.
 
5twins said:
All in all, a good day, but you're worrying about the wrong things. The Yamabond (or Threebond, or whatever) is semi-hardening. It never gets totally hard. That's the beauty of it and probably why it's recommended. It really doesn't matter how long you take for the re-assembly, it'll still be fine. Well, maybe waiting a year or two wouldn't be good, lol.
Click to expand...

5twins.....you're probably right. It's just that I've used this stuff a long time and sometimes it gives me fits if I just back up to fill in a spot.

You are 100% correct about it being a good day. Overall I'm happy and excited about hearing this bike run again. I'm going to let the rings bed in before I check compression with my gauge......but I can tell a BIG difference already.

Got busy and haven't got the engine back in the frame....but that's first on the list tomorrow. :thumbsup:

Take care and hope you had a good day too.

OH my......off subject but I think you will understand since I "think' I read somewhere you were a SR500 owner at one time???? I sat on a new (2015) SR400 yesterday......I'm a small bike/singles guy at heart and man oh man was that thing sweet.... I'd bring it home in a heart beat. :bike:

Gordon in NC

1975 XS650B going back together
1975 XS650B pile-o-parts
and a few BSA unit singles
 
Oh my, don't get me started on this "Singles" thing ...... too late ..... as you might have read here recently, I picked up some 650 stuff off Craigslist. Turns out the guy was a big time SR500 nut. He had several, some all tricked out (alloy tank and swingarm).
 
Gordon in nc said:
Now......a confession. After I torqued the head down.(the second time)..I adjusted the valves...I was dying to feel some compression...BUT I adjusted the wrong side first. THAT'S what peanut was talking about :) and I understand it now.
Click to expand...
thank you for that Gordon :) its more common than you might think.

Good luck with the rest of your rebuild ...it sounds like you're doing real well and enjoying it which is the main thing.:thumbsup:
 
peanut said:
thank you for that Gordon :) its more common than you might think. <snip>
Click to expand...


Yes sir, I can see how that could happen and NOT get caught right off the bat. Just as soon as I reached across the engine and felt the "other" sides valves....I knew what had happened and thought of what you had said. Saying something about it was the right thing to do.

Yes.....I do enjoy working on these things but I enjoy RIDING them better!!!....:bike: :laugh:

I just jumped another hurdle. I had to go in to my real job for a couple of hours this morning and when I got back.....I slipped the engine back in the frame. :) Like pulling it out, I was a bit worried it'd be a pain.....but I just tilted it a little, wiggled it a bit and it dropped right in place. :thumbsup:

LORD, where did all this stuff come from????? Why is so much easier/faster to take stuff off than it is to put it back on?????? :shrug: :confused: :shrug:

Mowing the grass can wait until the middle of the week....I'm going to see how much of this thing I can get back together before dark.

Later......Gordon in NC :bike:
 

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