1965 Yamaha YDS3C Resto Project

Hey Gents-

Sorta new to the forum and I promised on the New Member section to start a thread about my project. I finally got around to uploading some pics to my computer and decided now was as good a time as any to share some of my experience with the rebuild.

My father-in-law gave me the motorcycle back in 1987, just six months after marrying his youngest daughter. I guess he was really happy to get rid of her- the bike, that is…… Anyhow, I got the bike running straight away and was satisfied that everything worked. The only thing missing was the rear-view mirror. Prior to me taking possession, the bike had spent its life in California and New Mexico and was relatively rust-free. After I got it running in 1987, I neglectfully let it sit. Never did a thing with it until recently.

Fast-forward to one month ago. I found myself with a great deal of time on my hands and needed something to do. I was kicking around in the barn one day and uncovered this kind of forgotten, I'll get to it some day, project. I rolled it over to the shop and just started taking it apart. I had to assess what the years of neglect had done. For the most part I found it to be in surprisingly good condition. 27 years of dirt and dust washed away and I was ready to commit.

I had done much research trying to figure out what this thing was. I was able to reference the serial numbers and was excited to discover that it is a YDS3C Big Bear. Frame number is Y23C-15254, and the engine number is D10C-15254- A match! I knew it was going to need a few parts so I was quick to scour the internet for parts suppliers and it was soon obvious that there were ample parts to be had. Well, on to the pics…..

Started taking it apart before the notion occurred to me to take some pics. Gas tank, seat, side covers and exhaust pipes removed.



Still a lot of dirt. That little hand in the pic is my 2 1/2 year-old grandson. A great little helper!


Appears that many parts will need to be re-chromed.


9,909 miles. Already have the chrome bezel out to be trued-up! Found a website that sells reproduction instrument faces and tape digits.


Look to be original tires- Dunlop Universals. Wish I could find a new set of these. Closest thing I could find to the tread pattern are Kenda trials tires.


Carbs removed and cracked them open today. Frightening sight! Pics of those later. Appears I am missing the grommet for the oil injection pipes. Another part to order.


First time I have seen non-enclosed bearings. When I disassembled this and pulled up on the race, I thought WTF? The bearing had disintegrated? Don't you just love parts manuals to set your mind at ease? This is how it's supposed to look.


A view of the lower tree.



The coil boots/rubbers are trashed by dry-rot. The hot arid climate and 49 years have taken their toll on these guys. I cannot find a supplier for these as yet.



Enough fun for tonight. I forgot to mention that the seat foam had disintegrated into gravel-sized pieces. The seat pan is in good condition, so just some sanding and a repaint. New seat foam and seat cover on order. If you have any suggestions, please let me hear them. Those of you who have been down this path before and learned some lessons, please share them. I will do my best to keep up with you sharing my progress, frustrations and triumphs. A teaser- I split the engine case today and have some pics to share next time I update. Until next time. Regards~ Scott

 

Thanks. The cleaning is a real pain- even with the proper tools and consumables. Murdo, I've admired the results of your resto on the 5. You created a super-model from a skeleton! LOL. Really inspiring work.

I wish your take on the low miles and the engine condition were true. However, that is not the case. I will post more pics later today. The engine oil had the look and consistency of muddy syrup. Seems that some water or condensatoin got into the inners. With few exceptions, almost all of the internal parts have taken on a brown discoloration. It may be a form of rust, but not in the manner one would associate with the word. I am optimistic that all the parts can be reused and I can find some way to brighten them. Maybe some ultrasonic method?

Other than that, the gears are all in excellent shape. No wear or chips in the teeth. A couple of the bearings are obviously scrap candidates- those that were partially immersed in the oil took a beating. Those that were above the oil level seem to be reusable.

I'll take another look at the coil rubbers. I didn't think of superglue- thanks for that tip.

More later. Thanks again.

 

Here are a few more pics.

The shifter drum assy. Here you can see the discoloration I mentioned in a previous post. Granted, there is some rust, but I am hopeful a good cleaning will brighten things up a bit.





Right side crank bearing. She's an ugly girl but seems to spin well. Don't think I'll take any chances. Another part to order.



Top side of the shifter drum. It cleaned up nicely after I took the pic.



Shift levers and gears.



Same area wiped down a bit.



Carb bowl. Looks good to me- ready to reassemble. LOL Gotta boil these sinners. Nasty!!!



More ugliness….




Ready to split the case.



Had to do a lot of sweet talking to get her this far! Persistence and patience paid off…. Lotta banging with the rubber mallet.

 

More….


A few more turns on the screw…..



Five minutes later…..



Labrynth seal looks decent but will be renewed.



A shim fell out of the left side when the cases finally came apart. It goes on the ratchet gear that has dropped down.



Other than the rust, the gears are in pretty good condition. No chipped teeth or excessive wear.



Time to do the right side. This went a whole lot easier than the left side.



Freed the crank from the cases. Gonna need to press out the main bearings and install fresh ones. Also, new rod-end bearings.



Inside view of the right side case bearing. Looks like a bit of corrosion but should clean up easy enough.




That's all the pics for now. Making slow but steady progress. Today I finished painting the lower tree and the tail light bracket. YAY!!!

 

That Threebond looks like it'll do the job quite well. Just need to order some since it's not readily available off the shelf here in the US.

Murdo- great tip on the superglue for the coil rubbers. Worked like a champ! Thanks.

 

Thank you, Phil. Yeah, very disappointed about the condition of the internals. I had always stored it inside. If I had any idea that this would occur I would have tried to do something to prevent it. My fault entirely. I soaked some of the parts in a water-based degreaser at about 75% strength then hit them with a soft brass wire wheel. They cleaned up nicely but I will try soaking them in Seafoam for better results.

Thank you, Huntsman, for the Seafoam info. There is plenty of that on the store shelves! Gonna give it a shot.

I will post more pics tonight or tomorrow.

 

Thanks, Phil. I researched where to buy in the US and couldn't find any place that carries it. 1970's California has changed quite a bit over the years. Everything is known to cause cancer in the state of California and as a result the strongest thing you can buy is WD-40, LOL! I was able to find a web site where I can order Threebond but cannot find any stores that carry it.

 

While on the Threebond topic, I was wondering what product you guys have used to seal the engine case halves together. I have read that Threebond Liquid Gasket 1194 is a good product. Have any of you used it or can recommend something better? I understand that YamaBond #4 is no longer manufactured? Comments appreciated.

 

Thanks for theverification on the Threebond 1194 and No. 1 grey, Phil. I am nowhere in the process close to needing it but wanted to bounce the question here.

Sorry I haven't posted any pics in the last week- I have taken many to assist in the reassembly phase. I hope to post some of them this weekend. These smart phones are very handy little things to have.

I spent the past week doing more disassembling, cleaning and adding to my parts list. Finally got the entire engine taken apart with the exception of pressing out the bearings. Had to destroy the main gearshaft oil seal to remove the shaft. Oh well, it had to be replaced anyway. I also buggered one of the circlips on the gearshaft while removing the gears from the shaft- I was even using the proper tool! Go figure.....

Got around to inspecting the cylinders. For the most part, they are in very good condition. No broken fins, skirt rubbing, etc. Found some pitting inside the #2. I will get a pic of that posted this weekend. My plan is to bore them .025" over and purchase appropriately fitted pistons and rings. Additionally, I am gonna have to get them bead blasted- the soda blast didn't do as well as I originally thought. Question on the paint if anyone would care to comment- the black color I have seen on the YDS series in pictures appears to be something in between flat and gloss. I'm thinking satin? Murdo, you just recently did one of these- what did you use?

Carbs cleaned up nicely. Soaked them for a few days which got rid of a lot of the gunk. I have encountered a problem on one of them. I cannot break loose the low speed jet. It is recessed in the body of the carb and I cannot get it to budge. I'm afraid I have chewed up the head of the soft brass material. I've soaked the carb body in penetrating oil hoping that would work, but no. I've got it to the point now that I can't get any purchase on the screw head. Any ideas?

Shock springs are all going to need re-chromed. The front ones came off easily during the fork disassembly. The rear shocks, well, I have never disassembled one before this. Watched a fellow on Youtube use zip ties in lieu of a spring compression tool. As there isn't much tension on these shocks, it was fairly easy to do.

Anyhow, thank you for the advice and tips thus far, gentlemen. I will get some more pics of my progress posted in the next couple of days. Best regards~

Scott

 

Sounds good. Thanks for the info, Murdo. Looking forward to an update on your Bobber project.