Anyone recognize this old Yosh exhaust?

[Upshotknothole]

I think I was told it was an 1100 years ago, but can’t remember. I’m guessing by the shape of the header that it was for a dual exhaust bike. Tempted to see if it’ll clear the plastics on a 91/92 750.

[WeirdJimmy]

Headers look like a standard (4 into 1) Micron for a slingshot. I've no guess as to 750 or 1100

[baldrick]

it will hang lower on a 750, if it was designed for an 11,  so you might have issues with the fairing

[Upshotknothole]

So I had the header off on my 750 yesterday while doing an oil change, and decided to check for the hell of it. It fits and doesn't touch the plastics. I still need to pull the belly plastics again and make sure there's no signs of melting, and I'll need to swap out the oil pan as I currently can't get the drain plug out, and it's backfiring on engine braking pretty bad, so jetting will need to be adjusted. Also the 4-2-1 sounds really weird on a 750.

[fab]

4 hours ago, Upshotknothole said:

So I had the header off on my 750 yesterday while doing an oil change, and decided to check for the hell of it. It fits and doesn't touch the plastics. I still need to pull the belly plastics again and make sure there's no signs of melting, and I'll need to swap out the oil pan as I currently can't get the drain plug out, and it's backfiring on engine braking pretty bad, so jetting will need to be adjusted. Also the 4-2-1 sounds really weird on a 750.

Also the 4-2-1 sounds really weird on a 750.

weird good or weird bad?

[Upshotknothole]

41 minutes ago, fab said:

Also the 4-2-1 sounds really weird on a 750.

weird good or weird bad?

Pulses almost like a triple, but pulls strong through the revs though. Gonna do the valves and the plugs and make sure there aren’t any leaks anywhere. I’m also not used to having full fairings on the bike and with the new exhaust, all the noises sound strange to me right now. 

[cnap504]

Yoshimura “Duplex” ?

[Upshotknothole]

4 hours ago, cnap504 said:

Yoshimura “Duplex” ?

I thought the duplex always had the canisters connecting 1&2 and 3&4 on the header. 

[Jaydee]

12 hours ago, Upshotknothole said:

I thought the duplex always had the canisters connecting 1&2 and 3&4 on the header. 

Yes. Could be a Yoshi Cyclone system.

[Toddy64]

Yes the 4-2-1 downpipes are identical to the Yoshi Cyclone on my 89 1127, as for the can? not sure

[Upshotknothole]

I’m guessing it’s an old 1100 cyclone exhaust. It just happens to clear the plastics on my 750. Hasn’t really made it run any better though. 

[Upshotknothole]

Well, that was a short run with this exhaust. On the last day of a multi day trip up the west coast of the US, a mate rear ended me with his GSXR at a stop sign. I suspect I can get another canister for it, but the mid pipe got a nice kink in it too. The last couple of hundred miles home were loud and the bike ran like absolute shit on the bottom end. 

[denisd]

Ah noooo

[FJD]

Just resleeve the can, dont know about the midpipe

[Upshotknothole]

Friend that hit me is going to see about getting the mid pipe straightened at an exhaust shop. Might have a lead on a sleeve.

[Ade]

(1) Carbon Tubes – pj engineering

[Ade]

I have resleeved end cans and bought end caps from PJ Engineering. You should be able to find somewhere your side of the pond that sells carbon sleeves.

[2scars]

You are already in the states, have yoshimura fix it.  I was thinking to send the one on my newly acquired 750 that does have the 12/34 link pipes to them to be refinished.  

[Upshotknothole]

I’ll try hitting up Yosh, as well as looking into a new sleeve. Last night I went to pull it off the bike, and the mid pipe is so kinked where it slides over the header, that I doubt I’m going to get it apart without pulling the whole exhaust. I guess I know what I’m doing this weekend.