CB750 Barn find project - First Timer

[Rob62]

It should come out with two people holding it, too heavy for one. Put a load of rags round the frame and remove the exhaust stubs first then carefully lift out

[Nurse Julie]

Agree with Rob, the more protection you give the frame, the better. But, too much protection, you wont have room left to lift it out. Still very difficult to do even with 2 people, if you twist or tilt the engine in the frame even by a few mm, it will get wedged and then it is a nightmare. It is a pain but in the long run, stripping the bike down and lifting frame off is easier in the long run.

[K2-K6]

In the dim and distant past we always lifted them out of the bike standing up,  it's only on here currently that I've seen the lay down method.
Quite a few done on F2 for the valve guides etc.
Usually strip anything possible off,  newspapers about five sheets thick and taped around the frame tubes to stop chipping anything,  get a box or similar to load the engine out onto and with two people you can juggle it out.  if you got a support like the box you can stop and look round it at any point to see how you've got to move it.

With exhaust stubs removed and looking from the rhs it rotates a little clockwise to get the rear of the cases to clear the frame but it's only by a few millimeter. It only just clears.

I suppose with a bit of lateral thought you may be able to use a lift.  If you got something like a 7inch roof joist and put it vertically across the back where the carbs go,  then ratchet strapped it to the engine to secure.  If you had about a couple of meters sticking out the side of the bike and got the lift closest to the engine,  you could use the sticking out bit to counterbalance the engine while you withdrew it. S'pose you could call this the Catholic method with all that withdrawal going on.

[Underdog1]

Maybe this is the solution!

[Bryanj]

Having met you and thinking back to when i was your age and working on them all the time we used to lift them out by hand and carefully!

[K2-K6]

That looks most of the way there.  If it had a sleeve going over that scaffold pole to hold the engine straps you could pull the engine along the pole to get it out rather than shuffle the bike sideways, perhaps by using a ratchet strap to move the sleeve along the main pole.

As you say Bryan,  we normally lifted them out with two of us on it.  Quite a few friends had F2s which where in and out a few times 

[Trigger]

By the time you think and worry about getting the engine out sideways, you could of popped the wheels off, dropped the forks and removed the swing arm 

[Underdog1]

By the time you think and worry about getting the engine out sideways, you could of popped the wheels off, dropped the forks and removed the swing arm 

Yeah fair one, suppose trying to save time in this way might be a false economy.

With I hadn’t just fitted the new chain with roger link on. It’s a 100 link chain and the adjusters are almost all the way out so I can’t get it off the sprockets by moving the wheel forward. Maybe I can just pop the front sprocket off to get it off that way

[K2-K6]

Just pull the rear spindle out and roll the wheel forward to get the chain off the rear sprocket.

If there's no chainguard on it you can just lift the chain off and move it to the left to get the wheel out.

[Underdog1]

Well wrestled the engine back out this morning. Used the laying in the side method originally felt strong and tried with the wheels on but it definitely wasn’t happening so had to strip a few things off but got it out. Protected the frame with rags but let’s just say the new paintwork doesn’t look so new anymore

Going to split the cases this afternoon and see what’s up. Hopefully get the lump back in some point on the weekend

[Underdog1]

Well... found the kickstart problem.





Kickstart gear installed incorrectly. Seems to have been able to run the oil pump fine but when kickstarting it has caused this arm to hit the casing and do the above damage.



I’m not an expert (durh, that’s why this happened) so unsure of the best course of action. Does his need repairing or is it even possible to repair? The bit that’s broken off isn’t full thickness so there’s still a divot there for the spring to sit in

[philward]

Glad you found that - not just for solving the kickstart issue but dread to think what that chunk getting stuck in the gertrin would do

[Trigger]

Something wrong there, you should not be able to move that spring with your finger and it should be under high tension against the case 

The roll pin needs to come out and it all needs to be rotated. If i get time later i will put one in to a case and show you how it should look.

[SumpMagnet]

Anything ( well...within reason ) is repairable. That can be welded, but yoiu would want to take it to a specialist who understands what is needed and how to avoid distorting the cases.

My pop restores old Triumphs, and he has a regular welder who does wonders with smashed crankcases. Rod through the case....snapped chain torn through the gearbox....all possible. Not cheap...but in those cases, preserving an original set of crankcases is owrth the expense. Sometimes...it's not an option to replace as the parts are not readily available anywhere.

Couldn't say how important getting the metal replaced would be...but I definitely think that confirms you were right to pull the motor and find out hte cause, rather than just press on. A few marks in the frame paint are nothing compared to a ruined gearbox

[Underdog1]

Something wrong there, you should not be able to move that spring with your finger and it should be under high tension against the case 

The roll pin needs to come out and it all needs to be rotated. If i get time later i will put one in to a case and show you how it should look.

Yeah realised that as soon as I opened her up. That roll pin is a rascal, I’ve had it out once before and probably gave it a hefty tap back into place, doesn’t want to come out this time. Spend 30 minutes applying heat and pulling on it with pliers but no luck yet. Anyone got any tips?

Discovered the downside to hondabonding gaskets. No doubt they would have been Uber leak proof but they’ve obviously all been ruined now. Anyone got a spare clutch and gearbox gasket they don’t need