Separating top end from bottom end in one piece?

[alexdecker]

Hey all

I just found out that I can take the entire motor out of my Honda 550F in one fell swoop, without taking anything apart. That was nice. Now, I am wondering - I restored the top end of my motor, but I would like to replace my primary chain. I don't wanna take the entire top end apart piece by piece again. Is it possible to detach the entire top end in one go, or do I have to separate it piece by piece?

- Alex

[Bryanj]

You are going to have to take the cam out and disconnect all the con rods as you have to thread the chain over the crank. Its better to replace the 8 dampers in the primary drive at same time. Kawasaki chain is same but cheaper

[Sesman]

Rods can stay on.

[K2-K6]

Rods can stay on.

No they can't,  else you'd have to withdraw the pistons with the crank to get it out. Don't know if you can even get the piston to pass through upper crank case opening. 

Splitting the cases has undone the main bearings,  but you'll still have to split the rods as Bryan indicated.

[K2-K6]

Halfords advanced 1/4 drive sockets go up to 14mm size if that's any help, unsure what size those are.

Also Bahco 1/4 drive up to 13mm and really useful little set
https://www.screwfix.com/p/bahco-sl25-1-4-drive-socket-set-25-pcs/21134?tc=DX3&ds_kid=92700055262507126&ds_rl=1244066&gclid=EAIaIQobChMInorQ2NaD8gIVje7tCh0ZnwDtEAQYAyABEgKDWfD_BwE&gclsrc=aw.ds
Excellent quality and really tough.

[philward]

I've got the Halfords set of 1/4 drives sockets and the wall is too thick - I had to carefully grind a socket down when I did my 500

[K2-K6]

I've got the Halfords set of 1/4 drives sockets and the wall is too thick - I had to carefully grind a socket down when I did my 500

Just checked the halfords against bahco and they are within   .05mm from each other for OD so neither will work then.

[Sesman]

Eh…though we had split the cases? In which case the primary chain comes o with rods on. Either that or I have achieved the impossible…which is unlikely.

[Sesman]

Just reread the original post…pretty sure the pistons will come though the cases? It might even be easier to reinsert them given the generous barrel chamfer.

[K2-K6]

Possibly we are mixing visualization here.

If you flip the engine upside down and remove the bottom case (leaving the top end still assembled) then you'd either have to withdraw the pistons with the rods,  which may not be possible, or detach the rods from the crankshaft to lift it out and leave the pistons still in the bores.

Or are you saying that you'd remove the top end first,  in which case by undoing the main studs you've effectively separated the head and base gaskets.

[philward]

I think the confusion is what degree of 'I don't wanna take the entire top end apart piece by piece again' - does Alex want to leave head/barrel/pistons together or just head/barrels? I personally think the former would be best and just taking cam out so that crank can be withdrawn to facilitate primary chain withdrawal?

[Bryanj]

Correct Ken

[Sesman]

Just checked my dismantled engine. You are correct, rods off as the pistons will not pass the webbing.

[Bryanj]

Just for info later 500 you can fit 550 cylinders on but early ones the crankcase holes are too small

[Sesman]

Apologies for straying of topic, but did I read recently that if using the Vesrah gasket set not to use the 2 x O rings provided for the cylinder head oil control valve?. Do I just purchase two Honda items instead?