CB750 Barn find project - First Timer

[Trigger]

Don't think much of Bryan's wiring or is this the new fashion  kick start should always return, two springs to do the job.

[Underdog1]

I’m hoping it’s something to do with the clutch cover stopping the Kickstarter returning properly as this has been the issue for at least one bloke on the US site. Fingers crossed I haven’t assembled the kickstart spring incorrectly!

[Underdog1]

Charged the battery up today and gave it a good spin up off the starter but no pressure. Had a look in the tappet covers and it’s still dry up there. Going to have to do the Vaseline trick tomorrow.

Got the front brake set up, the actual bleeding was easy, the difficult part was tightening the fittings without the hoses kinking up.

None the wiser with the kickstart. Hoping that when I’ve got oil pressure it will all get the lube it needs and magically start working

[Rob62]

Maybe a good idea to get some engine oil in an oil can and give a good squirt through each tappet cover just to help avoid any damage until the pump starts pumping.... good luck with it UD!

[Underdog1]

Dropped the oil pump back out seems it was binding in a certain position and sticking tight. Took it apart and on the inner rotors the little dent marks were on opposite sides, flipped one of them round and it’s now smooth. Packed the rotors and oil ways full of Vaseline, reassembled and no cigar. Little disappointing as I was sure I had it!

As suggested above I’ve poured some oil into the tappets to avoid any damage but there’s graphogen in there so it will probably have been fine anyway.

When I packed the rotors with Vaseline I expected it to be pushing/sucking in Vaseline as I rotated the pump back and forth but it didn’t really - is this correct?

[K2-K6]

Something odd about that kickstart,  I'd be surprised if oil will make that return correctly. Looks like you'll have to get in there to see what's happened.

For oil pressure,  pull the oil filter off to see if it's present there,  it goes from the pump straight to filter first and comes out of the hole in the crankcase (not the filter bolt as that's the exit route to rest of oil system) if you put a bowl under it the oil should appear there first and you can put the filter on to continue.

Agree with Rob62,  you need to be careful how much you turn it over with no oil supply. Youucant do much about the main bearings but you can supply the cam with some oil manually via the tappet covers.

[K2-K6]

I crossed over your posting there.

With the Vaseline,  it'll only cause a vacuum and not go through the pump generally.  You need to make sure the oil is getting from tank via oil line to pump entrance,  if so then the Vaseline will pull the oil through with the vac it causes but if you spin the pump first before oil is available then it may not work.

[Underdog1]

I crossed over your posting there.

With the Vaseline,  it'll only cause a vacuum and not go through the pump generally.  You need to make sure the oil is getting from tank via oil line to pump entrance,  if so then the Vaseline will pull the oil through with the vac it causes but if you spin the pump first before oil is available then it may not work.

When I removed the pump just now oil poured out of the inlet oil way from the tank so it’s definitely got a supply that side. I’ll have a look if the oil filter is wet tomorrow.

Really don’t want to remove the engine again right now, to the point where I’d rather run it without a kickstart for a while before addressing it!

[Trigger]

I would not try running it until you have addressed the kick start problem, the cog wheel on the kick start can lock and then lock the engine via the clutch.

[Underdog1]

I would not try running it until you have addressed the kick start problem, the cog wheel on the kick start can lock and then lock the engine via the clutch.

Drat. I’ll Remove the clutch cover bits in case that’s causing something to bind tomorrow, if I have no luck.. well I guess I better gear up to get the lump out agin 

Last time I stripped it down to the frame and later it on its side. Are there any methods to remove the engine from a complete bike?

[Trigger]

Before fitting any engine you have to check that the engine turns freely via the kick start and every gear can be selected under load.
There are many problems if the oil pressure is not building up on a 750. It can even be a 0' ring at the wrong size or missing.

[Bryanj]

Trigger, that was before wrapping and whilst it was relatively straightforward it was switches from two models (LH and RH different) loom from another and bike a third so just about nothing except block connectors were a plug n play, still all keeps the grey matter working!!

[Trigger]

Trigger, that was before wrapping and whilst it was relatively straightforward it was switches from two models (LH and RH different) loom from another and bike a third so just about nothing except block connectors were a plug n play, still all keeps the grey matter working!!

Nice ! a ten minute job then mate   

[Underdog1]

Before fitting any engine you have to check that the engine turns freely via the kick start and every gear can be selected under load.
There are many problems if the oil pressure is not building up on a 750. It can even be a 0' ring at the wrong size or missing.

Well live and learn. I tested all the gears whilst turning the crankshaft but didn’t think about the kick start. Still hoping that maybe the clutch cover is interfering as it was quite a tight fit getting it over the kickstart spindle

[Underdog1]

Anyone got any experience pulling an engine out the side with either an engine crane or engine hoist? Can buy them second hand pretty cheap or even hire one for a day for £20.