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CB750F2 .... silk purse from a sows ear.
SumpMagnet:
No...the impact driver was fine. I do the same as you do K2-K6 ... I apply a little bit of twisting torque to the handle to make sure it is in contact with the screw surface it's going to press on. It also helps to let you 'feel' the thing turn when it starts to go.
I think the bit has just failed through long years of use. The large cross head is the one I used the most...and it's life is one of shock loadings. It's just called time.
Going to be a deep breath job if I have to seperate the carbs...but in order to fix the sheared pin part, I will need to do this.
No way I would try to move the thing back...made that mistake before. You think..I'll just ease it back...ping.
The slides don;t go that far up, so I will try an epoxy repair. I will also...assuming I get it all apart...stop drill the crack before I epoxy and maybe just 'V' the inner side a little to help the epoxy bond.
There also is a small grommet on the accelerator pump that has cracked and broken in two. It's part of part number 16201-393-004, and seems to form a seal and a support to the shaft on the accelerator pump. I can't tell if it is plastic or rubber.....but I think it was once rubber. It may explain why there is corrosion in the area below the diaphragm. Need to find a replacement for this while I am at it. Then order a set of carb rebuild kits..... but not until I have done the deed with the carb body!
Bryanj:
Got a set of 550k3 carb bodies you cab have cheap plus postage, i know that a lot of the internals are the same but not sure on the bodies. Have you got the pilot jets out to clean them? They clog up for a passtime, are a press fit and you need to twist and pull with vice grips
SumpMagnet:
Thanks Bryan....I'll do do e research and find out if the bodies are the same. Aside from the crack ..the carbs are not bad. Not taken the smaller jets out yet. Much still to do!
SumpMagnet:
Mixed dasy today. No work as I had a dentist appt...so some sneaky work was done on the motor.
Picked up a replacement impact driver as it was £8 to get the bit I needed....or £15 for a whole new one from Halfords with a lifetime guarantee. So....no brainer really. I got a few extra bits to replace ones that had been lost over the 30 years I had the tool...
It is only when you replace a worn out old tool with new that you realise how much slop has grown with time. New driver...3 taps...2 screws out. WOW. Didn;t even need a big hammer.
Flushed with success and with half an hour to spare, out came all the top bolts and into the prepared piece of card with the holes laid out...Flipped motor over. Lost the little screw in the top of hte neutral indicator thing I can't shift from the upper case...must go find that later. Undid all the bottom case bolts, breaking the torque in a sensible stress relieving pattern....gave the cases a few judicious taps on the big bits where the engine mounts are. Saw it shift. One section wouldn't budge. Resist the urge to 'pry' as I have seen a couple of minor scars on the cases where someone did...Find the bolt I forgot to undo after I slackened it...which forced me to turn the motor back over to get to it...then back over again...and hte cases parted like the Red Sea before Moses.
The Halleluia Chorus was playing on the MP3 and hte sun came out from behind the clouds.....
Nothing horrid met my eyes. I have not had time to check the shells or actually lift the crank out as I was now late for the appointment...but I am sure they understood. No time for photos either...so will do that later.
what I did have time to see was the state of hte crankshaft journals.
I had feared something looking like an aerial photo of a railyard.....rust....furrows....metal fragments. All these things were not there.
Instead, I could see a shadow line where the oil channel is in the shells, which was wiped with a lint free cloth....revealing a polished surface of shiny loveliness. I could not see a mark on the bearing surface. Not one. Which is how it should be. Running a fingernail across was smooth on all 4. That's a relief. Really is. Big ends all felt rock solid.
Of course...I haven't measured the clearances on the shells ( I have heard of Plastigage....understand the process...but it's not something I have ever done. )
Also...I am reluctant to mess with the big ends, as they all seem smooth and free from any slack I can detect. Should I? Or should I not. Bottom end on this thing looks really tidy aside from the gorilla knackered primary sprocket shaft and some idiot marks on the cases .
Also need some gasket sealant for reassembly ( Hondabond isn't it ? ... won't have instant silicon stuff anywhere oil lives )
After the last couple of days of hassle...today has started well.
Aside from the dentist.
SumpMagnet:
Stripdown is very, very nearly finished....and I am at the take stock stage....
I only have that annoying roll pin to get out to free off the kickstart shaft and the cases will be bare. How in the name of god does that thing come out? Do you just ruin it with molegrips...or can it come out in a state where it can ever go back in again. I assume they are available...
The other 'sticking point' is this damn thing...
Which seems fused on the shaft. Much WD40 and waiting. I have budged it around half a mill....if that. The soaking continues.
Had a good look at hte bearing shells in teh harsh light of day.
Don't look too bad, with only one of them really showing signs of wear. Don;t know whether they need replacing or if they would be OK to re-use.
Crank looks good...
Less good, with them free from their prison...is the rods. Quite a lot of surface rust. I assume this is a relic of standing long time. The rods themselves would only have got splash lube, and once the oil dried off...they were sitting in fresh air. The bores were fine, but....not the rods. Big ends feel smooth with no slop or noises. So....can these go back in...or do I need to budget for fresh. I'm out of my comfort zone here!
While I was in.,.I did notice something odd. I guess this might be further evidence ( if any were needed ) that someone was in here before me. The damaged clutch shaft...pry marks on the cases...and this. I assume the Japanese do know that 4...comes after 3.... Not here. By rods are labelled 1...2...3...and 3. That's not factory fit surely.
I also noted the pistons look more worn than I recalled when i popped the barrel off. I guess teh shiny oil has wiped away and with them in good light ( as in...not on the rods) it's a lot easier to inspect them. I have refitted worse....but that's something else I need to think about.
The crankshaft oil seal on the end was utterly buggered. I would be surprised if it kept oil in very well. Not as bad as the final drive seal though. The dried up chain grease was doing a better job of sealing than the rubber part.
One last thing.
I noticed a bit of marking on the bearing surfaces where the roller bearings for the gearbox and final drive sit. Is this normal? At some point some of those bearings look to have shifted. Do they need a few drops of bearing fit on assembly? Or has the case not been gripping them due to other issues? It's something I do not want to happen again.
Now to sit down and start writing up the shopping list.....and work out how long I am going to have to save up to afford what I need to do.
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