Riding for about a year, owner of a fairly rough 1991 model and enjoying the trials of running a 30 year old small bike 😀

 

 

Yeah, that does look a little rough! And possibly like it's frame has been modified! lol.

I like that you're apparently fixing some of it with a hammer though...  

If you can’t fix it with a hammer then it must be electrical!

 

yes, previous owner did rather a hacksaw job on the frame, I can see what he was aiming for but craftsman he was not!

current issue I have is CDI Unit. One unit and the bike will only tickle 50mph, the other it runs like a dream 60mph plus for about 12 miles, then misfires and conks out. I’m trying to find out if there is a modern workaround / new unit that can be made to work 

I suspect neither of them are set at factory settings...

No progress on CDI unit, have had a couple of used ones through EBay which haven’t generated a spark at all.

On the plus side Theory Test Passed and Module 1 booked for late June 😎

I have a 91 sr125 barn find, cdi is completely gone after many many hours of struggling and fault finding, cannot find the cdi code 5HO- M0 anywhere, I don't believe a newer cdi will work as 3 wires match and the rest are completely different i found... decided not to bugger up the original wiring and after lots of searching I stumbled across a company in Switzerland that has a direct replacement cdi for the 5HO-M0 cdi used 1982-94 which is more performance orientated yet matching the timing etc of the original cdi and what not, it also has connectors for a rev guage which is always a plus! It's a tad costly but I have ordered one and will be giving a go!

Here is the link if its of any use!

https://moto.chumm-ine.ch/shop/gb/startseite/23-zuendmodul-yamaha-sr-125.html

 

 

Edited September 1, 20231 yr by YamaMatt

Yamamat, let me know how it goes, I also recently came across them and am tempted. I will be selling my SR soon, but rather it was running perfectly before I sell it, and this looks to be an interesting option