Exhaust couplings

[rmc_olderthandirt]

Okay, I am fairly new to this dirt bike thing, and being fairly old myself I have come up with a fairly old bike, a 1986 Yamaha YZ125. This bike and I get along nicely and I am trying to keep it in reasonable shape.

One of the things that was pure jury rig when I got the bike was the exhaust system. The pipe is basically okay. The silencer doesn't silence much and I would like to replace it with a State Forest approved spark arrester model. Unfortunately, none of the online places have application information going that far back.

What I am really confused about is how the sections of the exhaust are supposed to connect. My exhaust system literally has pieces of beer can wrapped around the joints held in place by bailing wire. Removing all the stuff that obviously doesn't belong I see that there the pipe has a cup like fitting on it, then there is essentially a straight tube that slips inside it, and the other end slips inside the (non) silencer. I suspect that there was supposed to be some sort of packing in the "cup" on the pipe side but I have no idea what was supposed to hold it all together.

I looked at the various online parts catalog for stock Yamaha OEM parts and the exploded view looks different than what I have. This "cup" looks like it has been welded onto what could be a stock Yamaha pipe, and the extension tube looks like it could be stock.

So, the question is, how do you join these things together?

I see all sorts of after market pipes and silencers, but nowhere do I see what the heck joins the two together!

Any help would be appreciated.

 

[okieguy]

The silencer pipe should fit over the inner pipe and inside the outer cup. The newer bikes have a rubber sleave that fits over the joint to seal it. I don' t remember what they had on that year bike but a couple inch section of a small radiator hose with a couple hose clamps works nicely.

Guy