Losh's 1976 Yamaha RD 400

[losh1971]

 

[losh1971]

Yesterday I managed to get the bike frame stripped. I had to use three different methods. First I wire-wheeled all I could. Then I used up some old paint stripper to remove paint from the hard to reach places. Finally I sandblasted the frame. Reason I had to use all three methods was because I only had about 6-7kg of sand. I actually had just enough to finish the job, thankfully. For a moment there I was thinking I would need to head up the road and dig some sand and dry it in the oven.

I ended up painting it with an epoxy enamel from SCA. I added two or three capfuls of hardener to about 350mls of paint just to help it set quicker. Been fortunate that today is about 22deg so the shed was nice and warm when I applied it. Think the skylights helped warm the shed too, which is good.

The paint is dry already but it will take another week before I can start assembling the bike as it take that long to fully cure. I have a lot to work on over the next month. Fortunately I have two weeks leave in mid Jan where I should be able to get it mostly finished. I still have some minor painting to do on a couple of parts. I also need to tear down the brakes and clean them, as the rears were actually beginning to seize.

I also need to repaint the seat as I used acrylic and while it has last 20 years I'd like to freshen it up with hopefully some epoxy enamel.

 

[Lex]

I think its better that you stripped the bike down to the bare frame.
You will get a better result.

 

[losh1971]

I think its better that you stripped the bike down to the bare frame.
You will get a better result.

Yeah I agree. It wasn't until I had stripped it all down that I realised it really needed bare-metalling. I started feathering out the chips but soon lost interest. It was probably quicker anyway, taking it right back as the chips were vast and some paint was touched up with pressure cans.

 

[Wozza]

Nice work.....you should have painted the frame red red is faster and sexier

 

[losh1971]

Slipped the engine back into the frame last weekend, with the help from my neighbour. I noticed the paint is still fairly soft which I am a tad surprised at. Looks like it might take a few months to really harden up. Next step is to have the swing arm welded up where I ground out a bit of the reinforcing so I have some more clearance for the tyre. Also working on getting the chain alignment correct. I have found an engineer and now just need to see if he can either machine a rebate in my front sprocket or make me a new one. Apparently he is a bike enthusiast and makes bike parts. Hoping he is back to work today so I can get him onto it.

Also last weekend I stripped the rear MC as it was seizing up. Turns out the main seal is a bit pitted and probably over time allowing a tiny bit of fluid past causing some gumminess. Gonna put it back on and see if it holds pressure as it's pretty much impossible to buy a seal kit as they were made obsolete 20 years ago. I can get a kit from the States but at $150 it's damn expensive. Rear brakes only get very light use, at the last second or two coming into a corner. So if the pressure holds I think I will just leave it. Also need to see if I can source some brake fluid hose today. I used plastic fuel hose last time but it tends to go really hard and seems to absorb moisture. Where as the proper gear made from rubber doesn't.

 

[losh1971]

found an engineer today who was very skilled with excellent equipment. I rocked up and he said he can do the job straight away. I was like wholll ok. Ended up machining up some spacers and recessed the front sprocket 1.5mm. This means I can now fit the thicker spacer benhind the front sprocket. Overall i have gained 2mm on the front, which should be close to having the chain running straight and hopefully 4mm gap between the tyre edge and chain. Unfortunately the machinist busted a ceramic cutting tip on the sprocket as it caught on the shaft slots. Bloke said that the tips are 69 bucks each. He said he was happy to go halves in the tip and then charge me for materiala and time. I said nope i will pay for the tip plus the work. Because it wouldnt have been fair since the job was under an hour of time. In the end he agreed on 100 bucks. I thought 31 bucks for all he did was an absolute bargain. I have another sprocket, one more tooth i want to have recessed. I just need it sent over from Adelaide. Hopefully the tip will last enough to machine the second sprocket as it is damaged but not completely buggard. It may shatter but he said he will risk it. father in law migged up my swingarm, to which he did a nice job. Basically now i just need to bare-metal the swingarm and paint it. I wanted to sandblast it but 15 bucks for bag sand. So i might just wire-wheel it as i cant get hold of bulk play sand that is still reasonably sharp. Plan is to get the enamel on it Fri or Sat, so then in two weeks time i can bolt on the arm.

 

[losh1971]

Starting to get the RD reassembled now. All the painting has been done, with just the seat to go. Im working on primer at the moment. Building up the layers so i have it really flat when the top coat goes on. Today I managed to get the swing arm back in, tripple clamps loosely in with the forks all polished and shiny. Used somw autosol on the clip-ons and they come up quite nice and don't need a rechrome like i thought they would. This week i want to see if i can track down any chrome dome nuts and washers for the triple clamps. Not sure if you can still buy them or not. I checked the work on the modded sprocket and it is just right. In a week or two i will pop the back wheel in and check the chain alignment. Hopefully it is good. I want to get another sprocket rebated soon as i can, because I think now i have 10% extra torque i might be able to go back to a 16 tooth on the front like i used too. will get some pics up next week.

 

[Wozza]

yeah dome nuts are still readily available..just did my bike...try and get the stainless steal ones..and for allen head bolts try these
https://www.ebay.com.au/itm/chrome-...cs-AU-STOCK-/173650782975?hash=item286e64aaff

 

[losh1971]

Stainless is good but it can cause corrosion on the parts that are close by and normal steel. I will try the bolt shop near work before i wait 10 days for eBay parts to arrive. Good to know they can still be purchased.