Jump to content

New Member, Old Bikes


Tylerman
This post is 5701 days old and we'd rather you create a new post instead of adding to this one. You can't reply in this post.

Recommended Posts

Howdy, new guy here in Florida. I don't know if all the bikes I listed in my profile show up on the bottom of this post, if not I have a small collection of bikes from several different spots, some Kawasaki dirtbikes along with a pair of dissassembled H1s, a pair of Ducatis, an old Honda scrambler and a 74 Yamaha RS100B. I used to own an 81 XJ550 Maxim, and I still lust after the Seca version of that bike. Just wanted to intruduce myself.

As for the RS100B, it does not run, but cannot be far from it. It is in original racing green paint and chrome, although most of the chrome is rusted away. Compression is good, it clicks through the gears, I thoroughly cleaned the carb, but it lacks spark. I replaced the contact breaker and condensor with new, found a supposedly good used coil although I have not installed it since the old one still tests OK, I basically don't put much time into it but with the economy threatening to grant me more free time than I want I might dig back into it in the hopes of making it run again. Worst thing about it is the kickstart shaft is smooth, and a replacement has not surfaced. A good pair of locking pliers has sufficed to this point, but that is, of course, not a permanent fix and I don't want to weld a kick lever to it. Replacement of course means splitting the case, which means I would be feel guilty and stupid if I didn't do the crank seals and bearings, and bead blast and paint the cases and cylinder. So for now its just trying to find spark, all the rest will wait. It is actually original enough that I would like to restore it, although building a ts125 replica would be cool, too.

Anywho, hello again, I will probably lurk more than post, but hey, I'm basically a nice guy.

Link to comment
Share on other sites

Do you want an ad-free experience? Join today and help support the Yamaha Owners Club.
  • 1 month later...

Well as I predicted the economy forced my company to give me some free time, a lot of it, and I have gotten into this RS100 pretty righteously. I did implant the good coil and now I have spark! Problem is with the pliers/kickstarter I cannot spin the engine enough to get it to start. To compound that I found out that the clutch plates are now sticking so I cannot push-start it. Then I found a replacement kickstart shaft! Problem is it is in Seattle, so I have to wait for it to get here. Luckily I don't have to split the cases to install it, and since the clutch plates are sticking I will have a chance to correct that at the same time. Problem is the original good condition tank I have is locked, and I don't have the key nor do I want to risk damaging it by prying to cap off. So now while waiting for the kick shaft I am trying to find either a replacement key (the code is still stamped on the keyhole) or a decent locksmith that might somehow have a blank. The iggy swith is NOS and does not match, nor do I have the key for the seat/helmet lock but I am not too worried about that now. But I'm close, man, real close.

Link to comment
Share on other sites

Here she is, BTW.

RightSide.jpg

LeftRear.jpg

ClutchCoverOff003.jpg

She's rough but everything spins freely. And yes that is the wrong tank, from a CS-3 I think. As I stated above the correct tank is locked for the time being.

Link to comment
Share on other sites

  • Moderator

Still a nice looking bike you got there - and if she goes, then a bit of TLC will have her looking gorgeous in no time ;)

Link to comment
Share on other sites

Well crud I broke the clutch hub, and am hoping some JB Weld will hold it together temporarily.

BustedClutchHub.jpg

The new kick shaft assembly came in, so that is all ready and waiting to go in, the clutch plates are cleaned so I am just waiting for the hub repair. I only need the hub to work temporarily, if the bike runs well and I can title it (no small task in itself) then I will be tearing down the engine entirely, anyway.

Cleaned and waiting patiently...

NakedRight.jpg

NewKicker.jpg

Link to comment
Share on other sites

Grrr, no luck with this one. Once I finally got everything buttoned back up I found that I have a mere 90psi compression. I pulled the top end and the rings were stuck to the piston something fierce. Took about twenty minutes to get them both off, I took my time trying hard not to snap them. Now that they are free and cleaned up, I'll snug everything back together and hope that's work to get it to fire.

Quick question for the gurus.

The piston is stamped with a "5" adjacent to the arrow indicating piston front. I cannot believe that this thing is on its 5th overbore, although it does have over 15k on the clock, but the manual does not give piston dimensions and to make matters worse there is a "0000" inked onto the outside of the skirt of the cylinder. So I am at a loss to determine what size rings to order if'n I end up needing to. Any way to determine what size I've got?

Link to comment
Share on other sites

could it be 0.5 ie standard bore plus 0.5mm?

That's my best guess right now. Hopefully unsticking and cleaning up the rings will get me by for now. The more I think about it, the bore looks very fresh (still hatching visible) and there's very little carbon on the head or piston, for 15k maybe it has been gone through before.

Link to comment
Share on other sites

  • Moderator

That's my best guess right now. Hopefully unsticking and cleaning up the rings will get me by for now. The more I think about it, the bore looks very fresh (still hatching visible) and there's very little carbon on the head or piston, for 15k maybe it has been gone through before.

is this any use?

1975RS100B.jpg

I can send you a parts manual for a 75 one, this is where this info is from, PM you email if you want it

Link to comment
Share on other sites

Thanks Git, I have a pretty thorough service manual that I have been using that has those specs. I just remember from having rebuilt a couple Kawasakis that those manuals gave bore and piston diameters for the common oversizes and was hoping to find something for this Yammy. I am thinking it is the second overbore to 0.50" and have ordered new rings for it. I hope thats it, otherwise I cannot justify putting the effort into this bike to replace the crank seals.

Link to comment
Share on other sites

Thanks Git, I have a pretty thorough service manual that I have been using that has those specs. I just remember from having rebuilt a couple Kawasakis that those manuals gave bore and piston diameters for the common oversizes and was hoping to find something for this Yammy. I am thinking it is the second overbore to 0.50" and have ordered new rings for it. I hope thats it, otherwise I cannot justify putting the effort into this bike to replace the crank seals.

If you have the time why not do the whole lot, they arent complicated bike to work on although mine was a later model. looks like a nice project, keep it up

Link to comment
Share on other sites

If you have the time why not do the whole lot, they arent complicated bike to work on although mine was a later model. looks like a nice project, keep it up

I'd love to, but the economy struck me down so I am trying to get it running on the cheap if you will. A $10 set of rings is cheap and easy, beyond that it goes back into the corner and I get started on another project until funds become more available. Ironic, huh, I have the time but not the money right now, as soon as I get the money I will no longer have the time.

Link to comment
Share on other sites

I'd love to, but the economy struck me down so I am trying to get it running on the cheap if you will. A $10 set of rings is cheap and easy, beyond that it goes back into the corner and I get started on another project until funds become more available. Ironic, huh, I have the time but not the money right now, as soon as I get the money I will no longer have the time.

I understand completely, I'm in the exact same position, Im trying to get my dt125x running again as well as my twinshock motocross Rotax project, I lost my job last September and all I can really do is look at them, or clean the clean bits lol

Link to comment
Share on other sites

I'd love to, but the economy struck me down so I am trying to get it running on the cheap if you will. A $10 set of rings is cheap and easy, beyond that it goes back into the corner and I get started on another project until funds become more available. Ironic, huh, I have the time but not the money right now, as soon as I get the money I will no longer have the time.

What part of Florida you from mate? Going to Daytona Bike Week?

Link to comment
Share on other sites

  • 3 weeks later...

What part of Florida you from mate? Going to Daytona Bike Week?

Tampa Bay area, about 120 miles from Daytona. I am thinking, as I have nothing but free time, about going during the week to avoid the crowds. We'll see.

As to the RS100, I got the rings but apparently I was wrong, down in the bore the ring ends overlap so they are too big. As I cannot find the information on the correct size I sucked it up and ordered both a set of standard and 1st overbore (0.25) rings. Seems that rings here in the US run about 30 to 40 bucks, but if I get them from Singapore they are $20 including shipping, it just takes longer to get them. I can wait. I also managed to wrangle the gas cap off, the inside looks clean and rustfree, so that's one less thing, ya know.

Link to comment
Share on other sites

Tampa Bay area, about 120 miles from Daytona. I am thinking, as I have nothing but free time, about going during the week to avoid the crowds. We'll see.

As to the RS100, I got the rings but apparently I was wrong, down in the bore the ring ends overlap so they are too big. As I cannot find the information on the correct size I sucked it up and ordered both a set of standard and 1st overbore (0.25) rings. Seems that rings here in the US run about 30 to 40 bucks, but if I get them from Singapore they are $20 including shipping, it just takes longer to get them. I can wait. I also managed to wrangle the gas cap off, the inside looks clean and rustfree, so that's one less thing, ya know.

Love the Tampa/ St Pete's/ Clearwater areas. Been to Bikeweek three times - missed it this year though <_<

Link to comment
Share on other sites

  • 2 weeks later...

Grrr, well the saga continues, I received the 1st overbore (0.25) rings, still too big. Its been two weeks now and I am waiting on the std rings now. Process of elimination.

Link to comment
Share on other sites

×
×
  • Create New...