1975 Yamaha RS100

I was/am considering selling or parting out my 1982 XJ550 Seca.
It's in rough but repairable shape, I paid $250 for it and was asking $500 whole or part it out for $?.
It is mostly complete and I was told it ran when parked 3 years ago.

I got an offer to trade it straight across for a 1975 RS100 with a rebuilt top end.

Looks like a fun little bike that would be a lot cheaper to restore.

Anyone have any experience with the little 2 stroke?

 

You're right, it is a fun little bike and even though the engine only produces 10 hp, it's got a reed valve induction so there's a bottom end. A word of caution....as I remember, it has a 6 volt system so don't make the mistake of connecting a 12 volt power source or you will become intimately familiar with the electrical system as you replace the components<LOL>!! The carb issues of your big bike will be gone too....the RS has the coolest little carb that is nearly impossible to mess up.

You said the engine recently had a rebuilt top end.....you might want to pop the head and take a peek at the cylinder for scoring. The cylinder has lots of ports and if they aren't chamfered correctly, a ring can hang and cause damage. Fixing it now would be easier and lots cheaper then replacing a sleeve later.

Cool little power-house....if you do go into the top end, take a few hours and match all the ports along with the intake and exhaust (especially the intake-they all came mis-aligned) for a big power increase...if you want more, raise the exhaust port by 1.2mm.......NO MORE.....you'll think it's burning nitroglycerine it will feel so much stronger!!

good luck,

jeff

 

And Micron and Allspeed made pipes for them back in the day.
Al

 

I remember your thread when you got the Seca. Why'd you give up?

 

I had 1 of them it was my first street bike. Mine turned out to be a big p.o.s not saying the bike was bad. It only went 1 speed 65 everyday i tried different things to get more. Had to replace the crank big end brg at 14k. The wiring started taking a crap at about 17k 1 wire at a time. I kept it duct taped together to about 22k. At that time i was old enough to ride a bigger bike on the street and bought a rd250 was so much nicer even tho it was a friend of mines and he drove it into a ditch at 75mph replace the forks the right pipe and it was as good as new

 

BRSLK - I don't know what you weigh, but a 100CC bike just isn't gonna pull you safely thru traffic, depending on how you're gonna use the bike.

I'm looking at a GN250 with ONLY 235 miles !!

 

I wanna see a pic of YOU on that bike! I think you might outweigh it by a few pounds...

 

Actually I have reconsidered and I am going to keep the Seca and do a complete rebuild to as new as possible so expect several questions.

I also plan on buying the RS100 for the heck of it. I've always loved 2 strokes since I had an RD350 in the 90's.

I've had several bikes through the years... a VFR750...a Magna750...Nighthawk450 and the RD.
Plus a few dirt bikes thrown in for good measure.

So the Seca will be my winter project. I gotta get as much done as I can before spring as that is when the wife and I are knocking down the garage and house and building new. So come springtime everything is going into storage for a year.

I'd like to have the Seca in ride-able condition by April.

Bruce.