Author Topic: Sandcast #97 restoration (Read 197260 times)

Magpie · « **Reply #250 on:** April 19, 2011, 05:35:48 pm »

"My other sandcast"! Too much for me to bear.

Cliff.

markb · « **Reply #251 on:** April 20, 2011, 05:43:36 am »

Sorry. Sometimes I wonder if one is too many.

markb · « **Reply #252 on:** April 25, 2011, 10:44:17 am »

I’ve finally got a solution for the crank. Out of the nine journals, four were fine, no pitting and in size. Three had some pitting in the center of the journal but were also in size. The repair guy said it would just be a pocket to hold extra oil and isn't an issue. The last two (one rod journal and one main) had the most severe pitting and varied more than .0002” (.005mm) across the width of the journal and smallest near the edges. Those two are getting repaired. Should be done next week and cost me about $350. More than I’d like to spend but I’ll feel good about running it. Once I get it back I’ll Plastigauge everything to make sure everything looks OK.

Magpie · « **Reply #253 on:** April 25, 2011, 11:08:50 am »

Nice, a happy ending! Cliff.

Greggo · « **Reply #254 on:** April 25, 2011, 05:55:34 pm »

Here here for progress!!

76CB5WI · « **Reply #255 on:** June 03, 2011, 08:13:04 am »

This is awesome...subscribed.

markb · « **Reply #256 on:** June 03, 2011, 08:48:40 am »

Thanks. Sorry there hasn't been much action lately. I'm still waiting on the crank and I've gotten busy with my other summertime hobbies, boating and fishing. That, and getting some work done on the house and not enough time. Hopefully I'll get caught up soon and make some progress again.

SohRon · « **Reply #257 on:** June 05, 2011, 10:11:41 am »

Quote

I've gotten busy with my other summertime hobbies... That, and getting some work done on the house and not enough time.

Mark, I know how that goes, believe me! I got stuck with two remodels at the same time and just couldn't find time for my project... I know you'll be back at it soon.

This is an excellent thread; I've learned a lot about these rare bikes from your very detailed pics and the equally illuminating discussion. What a monster you got to start with, but what a great opportunity it is for the rest of us to see how an expert turns a sow's ear into a silk purse!

Can't wait for more...

markb · « **Reply #258 on:** June 21, 2011, 03:34:02 pm »

Sorry for the lack of posts. I've been really busy and I finally got the crank back last week. It looks really good. Here's a before:

And an after:

Now to plastigage the bearings.

Greggo · « **Reply #259 on:** June 21, 2011, 03:46:48 pm »

Great to see some progress Mark!

y2kc0wb0y · « **Reply #260 on:** June 21, 2011, 06:40:59 pm »

how did the other side of the crank turn out?

CB750faces.com (Lecram) · « **Reply #261 on:** June 21, 2011, 11:20:50 pm »

Quote from: markb on June 21, 2011, 03:34:02 pm

Sorry for the lack of posts. I've been really busy and I finally got the crank back last week. It looks really good. Here's a before:

And an after:

Now to plastigage the bearings.

Great job,

How can you decide what size bearings you need? I can imagine that the standard bearings of Honda don't fit now.

markb · « **Reply #262 on:** June 22, 2011, 06:27:43 am »

Quote from: y2kc0wb0y on June 21, 2011, 06:40:59 pm

how did the other side of the crank turn out?

Sorry, not sure what you mean. The other side is the same. The other end didn't need repairs.

Quote from: Lecram on June 21, 2011, 11:20:50 pm

How can you decide what size bearings you need? I can imagine that the standard bearings of Honda don't fit now.

The journals were built up and then reground to exactly the correct factory size. So the standard bearings will be used.

y2kc0wb0y · « **Reply #263 on:** June 22, 2011, 10:01:27 am »

Quote from: markb on June 22, 2011, 06:27:43 am

Sorry, not sure what you mean. The other side is the same. The other end didn't need repairs.

The before and after photos appear to be shot 180 degrees from each other on the same end.

markb · « **Reply #264 on:** June 22, 2011, 10:42:35 am »

Just happened to be the way I put it up on the bench. Its the same all around. Here's a shot of the other side.

lone*X · « **Reply #265 on:** August 15, 2011, 02:12:21 pm »

Hey Mark, how about a update? Making any headway?

markb · « **Reply #266 on:** August 15, 2011, 03:25:50 pm »

Sorry, things have been pretty much at a stand still so nothing new. Too many things going on this summer. But about another month or so I'll be back into it.

Greggo · « **Reply #267 on:** October 02, 2011, 02:48:41 pm »

How about an update Mark?

lucky · « **Reply #268 on:** October 03, 2011, 12:14:13 pm »

Now spray down that entire crankshaft with Lube before it rusts. It can start rusting in 4 hours.

lucky · « **Reply #269 on:** October 03, 2011, 12:19:17 pm »

Quote from: markb on November 13, 2010, 08:56:09 am

Well, things aren't getting much better. I got the transmission cover off OK but wasn't happy with what was underneath it. I guess that's what I should expect.

I've got all the screws out on the rotor cover but one. It's stuck part way out. I was hoping if I could loosen up the cover I could get some rust loosener down by the threads. I wonder if this is the hole with the pin. I soaked all around the gasket edge hoping that will loosen it up. I've got a funeral to go to now so I'm going to let her soak.

I would cut the head off of that case screw and slide the case off. Then you can use a little heat on it with a propane torch and get some vice grips on it.

When it gets hot the lube really gets in there. Heat always helps.

All that stuff in the shifting case will be fine after it gets grit blasted and replated or dry lube technology applied.

lucky · « **Reply #270 on:** October 03, 2011, 12:23:35 pm »

On those petcocks I noticed also that the early petcock had steel fuel tubes instead of the inferior brass ones.

Brass and aluminum is the WORST combination galvanically. That is why many aluminum carb parts were destroyed. The aluminum sacrifices itself to the brass.

Old Scrambler · « **Reply #271 on:** October 03, 2011, 12:26:49 pm »

Summer progress is measured in miles on the road......not hours in the shop!

Rust starts NOW............We boiled a drive-chain clean and used WD40 for a quick lube to keep drag at a minimum during a speed run on the the Bonnevile salt-flats. The chain was rusted tight a few days later.

lucky · « **Reply #272 on:** October 03, 2011, 12:29:41 pm »

Quote from: markb on December 06, 2010, 06:07:04 pm

I hesitated posting this because I figure I might get some “I told you so’s”. But maybe someone will have some good input so here goes and I know I’m not the first one this has happened to. I had some time over the weekend so I decided to work on getting the starter motor out and tackle the studs. I took it slow and worked on the motor for about an hour and finally got it out. On to the studs. I already had one out and had been heating and soaking all week. A couple were a little stubborn so I heated and soaked them and moved on to the next ones. After about another five hours, everything was going good until I got to #14. I use a vice grip and if it slips I know the stud is still too tight. This worked on my last two projects and never had a problem. This one actually moved about a half a turn and SNAP. Son of a….

Here’s a close-up. It broke off about an 1/8” above flush. That’s the good news. I’m still thinking about what to do but I think I will make a bushing that’s c’bored on the bottom the diameter of the stud and a smaller hole drilled through the top so I can get a pilot hole exactly on center. Then drill out the stud using an 8mm x 1.25 tap drill and then pick out the threads. I’m thinking I might not keep track of my hours anymore.

Here is a suggestion that may help.
Get that case ultrasonically cleaned THEN remove the studs and bolts because the ultrasound may break up those molecular bonds and the corrosion.

lucky · « **Reply #273 on:** October 03, 2011, 12:32:53 pm »

I started working in a Honda shop when I was 16 and now I am 62 and still working on motorcycles. That engine you are working on is one of the worst I have EVER seen. It looks like it was underwater. Then dried out,then underwater etc.,.

lucky · « **Reply #274 on:** October 03, 2011, 12:50:13 pm »

I spent my life welding.
If that was my crankshaft I would get it x rayed for cracks. See if it is worth repairing.
But welding always has consequences. Like weakness in the HAZ (heat affected zone) and possible warpage, and on such a small crank it is not worth it.

I would replace the crank if it needs it, and change that 12mm bolt to a 10mm bolt.
I mean think about this .
What is better a original crank that has problems and could possibly fail even if you repair it, or a new crank that someone with a magnifying glass could say"it's not original.

I would want the NEW crank that looks like the original.

After all it is inside the engine and no one can see it. It is not like an aftermarket part on the outside of the bike that is obvious.

What good is a complete restoration that you would be afraid to ride?

News:

Author Topic: Sandcast #97 restoration (Read 197260 times)