Feb 1st 2017
It’s been a busy month in the shop/shanty in the back yard. February 1st will see Houston operations take up residence in a new building. It will be some time before any level or organization is attained so delays in project progress are expected.
However, bullet points on projects from the past few months-
It smoked, made a ton of racket in the top end, and showed signs of general neglect over 14 years.
Figured it was the piston/rings. Quick swap of those, quick post on craigslist, proft.
Piston, rings, and cylinder were found to be bad to be fair. I replaced those and the bike ran better (no smoke) but still knocked. Which mean it was the rod.
So back to ebay to scrutinized crankshafts. I found one that looked good to me, and all the pieces were in place.
Knowing that I was moving at the end of the month, I wanted to get started on the motor ASAP since I have no problem powder coating in my food oven (can’t be that bad for you, right?).
Tear down was nothing spectacular aside from the fact that this grey, thick, shiny goo was hiding in all of the cavities and bends inside of the cases. It was a ferrous sludge of bearing and connecting rod material. It was encouraging, really, because it meant the rod was bad. A smoking gun, if you will.
As with any job that requires replacing the crankshaft or rod, my thought is that you might as well powder coat the cases while you’ve got them stripped down.
Every bearing and bit was washed in gasoline (nature’s soapy water) to clean them. Bearings were checked for rough spots, 2 were found to be bad.
While washing the parts in my bucket of gas, I put a bunch of magnets in the bottom to keep the metal particles from winding back up in the bearings or parts.
Cases were powder coated a wrinkle white with maroon accents.
When it came to the cylinder and head, I wasn’t sure if the bad rod had damaged the bore. It looked okay, but at $70 for a rebore and $60 for an oversized piston and rings, I figured it was cheap insurance. So those got sent off to the machine shop and I focused on the cylinder head.
People put different cranks and larger pistons in these engines, but its bore and stroke is already maxed out pretty much. It’s a 125cc engine that’s been made a 200. And I like Japanese engineering and think that those guys know more than me about how to build an engine. So I wanted to keep all that stuff stock.
Where I did take some creative freedom was the ports. They were thoroughly widened, contoured, and smoothed. It cost nothing to do. File under- Why not?
Current status- going back together. Trans and crank are back in and working. Waiting on a .99 pin and the rest of the motor can go back together completely. The frame needs a bit of touching up. I’ll paint it and make it look new which should be a 20-30 dollar affair, and then it all goes back together.
Planning to keep this for a bit, take it to the beach, find treasure, and then sell it.
NEW FAMILY MEMBER!!!
Craigslist has been good to me. Stumbled across this beauty and for $300 American pesos, I couldn’t pass it up. Less than $1 per cubic centimeter is a no brainer in my mind.
Original. First year. 1971 Yamaha RT360. edit: 1973 per the VIN checking this eve.
It looks a bit rough, I’ll grant you, but a lot of it is there. Needs a seat and rear blinkers. Have a bill of sale. The guy said it was sparking but he didn’t know how to adjust the points. I think it needs a new condenser. It’ll get polished and cleaned up. I’ll rebuild the carb and replace the crankshaft seals. Then this one is off to market.
Other projects on standby
1984 BW350 - Frame is painted. Needs wheel and steering bearings. Most of bike is complete. It will get cleaned up and put back together one day.
1971 DT250 - New oil pump (from ebay) is on hand. Exhaust needs to be rewelded. Seat needs to be made.
1968 Bronco - Frame and body have been separated after a weekend with a reciprocating saw. Ready for rand blast and body work.
1971 Pinto - Much needed parts procured, mostly interior bits. Found a mint 71 in Sealy to borrow parts from. It's probably a better candidate than the one in San Marcos.
Kennedy Performance Engine adapter is on order to mate 351c to Audi 016 Transaxle. Porsche 911 rear suspension is on hand. Rear subframe and frame connectors to be built.