Suzuki TS185 Tach Drive Problem
 

My ‘73 TS185 tach drive isn’t working. I bought the bike in reasonable condition but it was missing gauges, headlight, and turn signals. I’ve added those items plus very good condition gauges however, after attaching a new tach cable to the drive port on the back of the engine the tachometer wouldn’t operate. The opening had been uncovered for no telling how long and likely accumulated debris inside it freezing up the drive shaft gear. The shaft wasn’t turning the cable insert. I replaced the tach drive shaft and cover tube with a good used working one but still the tachometer would’ve operate. I can only surmise that whatever gear the shaft connects with in the engine case is worn out also. My question is which part do I replace inside the engine? I don’t see anything on diagrams from different OEM parts suppliers for this year model, or other close year models, that connects the tach drive shaft to the transmission or oil pump. Someone said there’s a plastic gear that connects to the oil pump. My second question is, do I have to split the engine cases to fix this?
Thanks,
rbevel

I'm no expert on TS185s but as far as I know the tachometer is driven from the oil pump via a helical gear shaft. My guess is you can get to it without splitting the cases. Take the oil pump cover off and have a look. If it's the shaft it's still available from CMSNL.

There are a few others here who know the bike but in the event they don't see this post you could do worse than joining the VJMC group on Facebook. TS185's are popular so there's bound to be someone there who will know exactly what your problem is. I spent 6 months trying to find a wiring diagram for my '69 Yamaha online and someone sent me one in an hour on Facebook.

Thanks for the Tip
 

Thanks for the tip about VJMC. I’ve always contemplated joining. I visit their exhibit at Barbers VintageFest every year. Anyway, I checked oil pump compartment and it looks like I would have to remove the assembly to get to the shaft. I’m not sure if I could remove the connecting shaft without splitting the cases though. Unless the helical cut gear is narrow enough pull through the oil pump opening end, I don’t see much of any other way. It just seems there should be another solution to splitting cases! Just another learning experience I guess!
Thanks so much!
Rick