Topic: The Rebuild - A 550 Tale

[cabrala]

As promised; an update:

Spent Saturday tearing down the spare motor with hopes of finding good bores, pistons, rods and crank. Had no real issues except the occasional lack of patience and a cam chain tensioner was uninterested in being evicted from its home of 30+ years. I walked away a few times, which helped me to not bugger something up real good.



The beginning of a nest


Not so bad after all



The pistons and rods are moving freely and the bores, to my untrained eye, look to be very usable in my rebuild. I'll be having Anders take a look at them when I make my way back up to the New Hampshire shop in coming weeks.





Removal of clutch






Documenting case bolts







Took me a while to break the cases free due to thinking I removed all of the bolts until I kept finding more . A few whacks with a rubber mallet broke the seal and some finesse with a pry-bar got them separated.






I don't have the proper tools to remove the primary shaft (according to the manual) and while I have plans to have it removed properly, I couldn't help but research some options...

Spark plug


Thread in a spark plug and tap at the hex nut (on the plug) while rotating the shaft. This didn't work for me because
1) I have the option to remove it correctly soon, so why risk it?
2) The directions in the "Tips & Tricks" section were a bit vague in terms of tapping at the plug.

Tapping or drifting from behind the oil pump




There isn't very much of the shaft showing that I can get a wooden (soft) drift onto. Is it expected that I tap on the bearing, as that seems to have the most area showing?

Additionally, there was the option of using one of the long engine bolts (that attach it to the frame). The thread is again the same as the primary shaft and can be fitted with some weighted spacers or sockets; used as a slide hammer. I didn't try this method as I didn't have the proper materials at the ready.

In conclusion today, it looks as though I have most of the parts I will need to button up my cases and get another 30 years out of her. I'm also trying to take into account any parts that should be replaced because, well, it's already apart; so if you have an opinion please make it known.

[IAmCitizenMe]

Subscribed!

[dave500]

knock that shaft with a brass or wooden drift and itll come out easy.

[knowsnothing]

I have an assortment of brass drifts and a nice variety of hammers.  Give the word and I will have that thing knocked out quick.   

[cabrala]

Holy cow! It's been over a month since last post and I've been pushed out to Pg. 4; I better step it up.

Well, good New Year's Eve morning.

The holidays have made forum life a bit slow, but I have recently begun the hunt for parts to start buttoning back up the cases; getting the mighty 550 into running condition. Be patient with me here on this post.

Problem #1: I'm trying to select the bearings, both main and rod, but at the moment I've focused on identifying the mains.

The manual states to pull the crank and reassemble the cases without the bearings. Mic' the journals of the crank, with the measurement falling into either "1" or "2" in the table. Then, using a cylinder gauge, measure the diameter of the seats, with these measurements falling into "A", "B" or "C" in another table. You end up with each journal and seat having a specific number/letter combination which corresponds to the final table and lists the type of bearing needed, "A", "B," "C" or "D" (black, brown, green or yellow). See attached photos.

I have neither a cylinder gauge to measure the seat diameters nor a torque wrench to tighten the cases to spec, so I was hoping to find another method using the production marks stamped on the lower crankcase in conjunction with the numbers stamped on the crank. The lower case is engraved with "BBBBB", while the crank is stamped with "1A-M-1A-1A-1". I am most uncertain with the crank numbers but that was the best I could see and make out. My thought was to take the "B" off of the case and the "1" off of the crank, insert them into the final table (in the manual) to determine bearing color...in this case greens.

The "1A's" and "1" on the crank were stamped in a faded black while the "M" was actually engraved into the cast iron counter-weight.

I know the above is a bit wordy, but I'm hoping for some insight and experience.

Problem #2: The cases and jugs are fresh out of an ultrasonic cleaning and need to be prepped for paint. I was hoping to soda blast them but is there really any place to do that at this time of year; assuming most are blasting outdoors? Maybe you have some other ideas for prep that can be more...contained? I'm open to ideas here.

Additionally needed are thoughts and methods for masking off the parts for prep and paint. I remember reading about some MRieck tricks for painting the engine. Again, I am all for being sent some information to research.

I think that's all for now! Happy New Year!

[cabrala]

Last page of the bearing selection...

[rb550four]

The primary shaft removal tool I use is ( I forgot exactly as I haven't done it in a couple months) is either the top back engine mount or the bottom engine mount minus the pegs. I thread it into the primary shaft end on the clutch side, leave the nut as a stop on the other end,adjust an adjustable wrench so it just slides on the bolt, a couple light taps with a dead blow hammer ,and the whole shaft slides out easy.  slide it out slow because you'll want to see how it is put together as you take it apart, there is bearings on there too that you may want to check out and/or replace.  you'll want to do that before you put it all back together and have another failure . have you checked the slack on your primary drive chain? when they run slack, it starts to mark and eat the bottom mount (perch) for the timing chain adjuster.they don't just stretch lengthwise they swing left and right too, that's the action that eats the perch.
   If you haven't pulled the primary shaft and think that you can get away with it, please don't, you are right there,at least take it out and inspect it. Piece of mind is worth allot when you've gone this far.  RB

[cabrala]

Hey RB,

Ended up getting the primary shaft pulled using an engine bolt and slide hammer. The chain is in good condition with no deformation, or slack, in the linkage. No marked surfaces in the case from excessive wear.

You're right too, while I am in here I am going to get as much piece of mind as possible. I've got the parts I need, sans some main bearings, to reassemble the cases so I'm moving in the forward direction.

Next up is prepping the engine for paint and buying more parts for assembly.

[purf_man]

I like using an engine bolt and the flywheel.....stuff I already have.

[iron_worker]

On your comments about bearing selection... I think the method described by the manual is the method which will give you the correct bearing clearance even when considering wear on your crankshaft main journals.

The method you are describing would be replacing the main bearings with what was in there from the factory (I think). This will give the proper clearances given your crankshaft has not worn too much. If your crankshaft main journals have worn undersized then you may need a different color bearing shell than the factory had used.

I'm not 100% positive on this but maybe someone can confirm.

IW

[cabrala]

On your comments about bearing selection... I think the method described by the manual is the method which will give you the correct bearing clearance even when considering wear on your crankshaft main journals.

The method you are describing would be replacing the main bearings with what was in there from the factory (I think). This will give the proper clearances given your crankshaft has not worn too much. If your crankshaft main journals have worn undersized then you may need a different color bearing shell than the factory had used.

I'm not 100% positive on this but maybe someone can confirm.

IW

IW,

You are correct in understanding the method I plan on using; replacing the bearings to "default factory settings" per the cross reference of crankcase and crank numbers. I spoke to Anders and Mike R. about potential clearance or wear issues and came out of those still believing it's ok to go with the factory, which in my case were greens (blacks and yellows are no longer available).

Nevertheless I will be sure to mic and measure as much as humanly possible prior to assembly...

[minimo]

Crush, loving the documentation and crisp photos. Thanks for doing that. Following along as I stumble with my 550 rebuild. All the best to you and yours!

[cabrala]

Crush, loving the documentation and crisp photos. Thanks for doing that. Following along as I stumble with my 550 rebuild. All the best to you and yours!

Thanks Minimo! Things have been slow-going on the build. Weather has been too cold to paint, so I put that aside and bought a spare motor to run until I could complete work on the original. Went to replace the valve cover on the spare and found two bent valves so now I am replacing the gasket from the base upward. I hope to have it together in a few weeks once work slows up a bit.

I also picked up a 1975 CB750F that is taking up some of my time. Too many projects with too little time