1975 XS650 Build Ep 1, Unseizing the Engine

Short intro to a new project and unseizing an engine that has been neglected for years.

[@guypigache2105]

Glad to have you back. Dismantled my engine a few weeks ago. A few bits still defeating me. Valve guide removal a swine. Good luck

[@sandmanGT350]

Great to see your taking on another xs project. Those 650's are such a hearty bike. Looking forward to the build. Good luck

[@NatsNackersYard]

You are a very patient man mate!

[@xs650abear6]

I freed up a stuck Triumph Bonneville engine using Marvel Mystery oil and a oxy acetylene torch with rosebud tip. Heating the cylinders was what did it for me.

[@2wheelworkshop]

I'll give that a try if I ever need to do it again.

[@giancarloferrari333]

Thank you! I will try to do it in the same way!..

[@Tater-]

Fuck yeah and we are back!!!

[@juscozcustoms]

you definitely got a challenge this time. can't wait to see the build take shape and what style you build it into

[@juscozcustoms]

Sounds good @@2wheelworkshop cant wait to see it

[@juscozcustoms]

@@2wheelworkshop are you doing the same color tank as the last build? You know... for cheaper rego 😉

[@juscozcustoms]

That's an awesome idea. no good trying to share number plates if your riding together

[@guypigache2105]

Brodie: Sorry, a long boring post. Engine dismantling tips (ie bits I fouled up). Cross-head screws: 4 or 5 components are fixed within the engine using normal Japanese butter steel cross-head screws (eg the stator; cam chain tensioner bracket). Remove using penetrating oil and then an impact screwdriver with exactly the right head. I ruined at least 6 bolts. Rocker arm pivots. Haynes manual says to use a 6mm bolt and broad washer to pull them out. That is half the story. You need a series of different length bolts; washers, and hollow tube/sockets. You can only screw in about 4 mm of the bolt thread before it hits the end of the thread in the rocker pivot. At which point remove the bolt and use a shorter one. Gradually the pivot is pulled out 4mm at a time. When the pivot emerges from its hole you will need to pull through a socket/length of tube that fits around the pivot. Splitting the crankcases: My engine had never been disassembled and was also seized, in any event, the cases just would not separate. So I got two lengths of 4"x2" wood. One ran down the length of the engine between the cylinder head studs (I had removed the pistons and cam chain). I used thinnish slotted angle iron to bolt the wood beam to the front and rear engine mounts on the top crankcase. The other beam I ran lengthways under the lower engine case. Angle iron connected it to the lower crankcase's rear engine mount. At the front, there was no engine mount so I used webbing tie-downs to connect the beam to either end of the crankshaft (stator removed as well as first drive cog). The idea now is that you force these two beams apart and they pull the two crankcases apart. To do this drill 4 vertical holes through the 4 ends of the beams; push a long piece of 10mm threaded stud through each drilled hole of the top beam down through the holes in the bottom beam. Use nuts and big washers to fix the stud to one of the beams; with the other beam you just need a nut and washer on the inner surface of the beam. You can now drive the beams apart by opening up the length of stud between the beams using the inner bolt. (I wish I could have sent a picture). This technique worked immediately and the crankcases slowly separated. Note: using webbing at the front was not ideal as it stretches. I got a crankcase gap at the rear quite quickly. At the front, it took longer (at no point did there ever seem to be undue bending forces on the crankshaft). Gear selector forks: Tricky to get out because they each have a pin system (to engage in their selector drum slot). These should "drop out" once their retaining split pin is removed. Mine did not. I used penetrating oil plus a feeler gauge inserted between the selector fork and the selector drum and this gave the ends of the pins a slight nudge to come out, enough to allow the forks to move freely on the drum. Valve guides: Putting the head in an oven at 220 C (my BBQ) has not worked. They did not just "drop out" per Haynes or the XS650 Forums. To get the specialist drift tool will be tricky at the moment (Xmas, Brexit). I plan to use: heat again; a heft G clamp; a valve spring collett (fitted around the large head of the valve guide); a fabricated driver = a bolt of the same diameter as the valve stem + two copper washers (to bear on the end of the valve guide) + a wide steel washer under the bolt head to bear on the copper washers. I hope I can tighten the G clamp and that: the copper washers will save damage to the end of the valve guide; the bolt's threaded section should help locate this fabricated driver; and the valve guide head can be pushed out within the valve spring collett.

[@guypigache2105]

@@2wheelworkshop Had a better idea with the valve guides. Ordered 3 very long Allen head M8 bolts (110mm, 120mm, 130mm). Thread diameter (8mm) is the same as the valve stem and allen head is circular and the same diameter as the end of the valve guide. Add a copper washer then push the bolt through the valve guide and then through either a deep 22mm socket or my valve spring collet. Add a bolt and washer on the end. Now after heating I think I should be able to tighten the nut which should draw the guide up inside the socket/collett. Might not have enough reach to draw it out fully but should get most of the way with a brass drift to hammer out the final bit.

[@justheretoinspireyou5803]

Seized oil you don’t take the spark plugs out they’ll break in there

[@louisvanderwilt5438]

Wouldn't an impact driver be a better than a breaker bar? Maybe not the hammer impact drivers, but the electric or pneumatic.

[@2wheelworkshop]

You want to apply nice even pressure. If you use an impact driver you will either over torque the rotor nut or loosen it depending on which direction you try to turn the engine. Also, a lot of the impact will be absorbed by the bearings, potentially damaging them and applying minimal force to the piston.

[@rakistangel]

I have the same challenge with my xs engine. Just a question, what can be a replacement for penetrene? I wanted to do this first before I tear down the whole engine. Might work. Thanks in advance

[@rakistangel]

@@2wheelworkshop thanks for this really appreciate it

[@jerrybigrig9475]

Did you get your engine freed up..??

[@cheeseburger_man1457]

Just bought a Honda xr80r with a locked up motor for 150 dollars lol

[@2wheelworkshop]

That was a good buy.

[@brandonroach2152]

Why were you tightening it then making it loose, then tightening it, then loosing it, tight, loose repeat for duration of video

[@2wheelworkshop]

I wasn't tightening or loosening anything. I was using the rotor nut to try and turn the engine one way, then the other. I was limited I the torque I could apply by the tension on the nut (too much clockwise and I would over-torque it and too much counter clockwise and I would loosen it).

[@brandonroach2152]

@@2wheelworkshop ahhh okay, I understand. That was my faut