GS550/ 650 Exhaust

[tedk]

I tried searching forum for a clear answer, so if I missed it let me know and point me in the right direction. Otherwise, are the 550 and 650E or G/ GL exhaust port diameters at the header the same? In other words can I take a 550 pipe and while it may not bolt right up, I can modify, will the pipe fit in the head opening - bolt pattern and all on a 650? Am I explaining myself well? Probably not.

[Toasty]

I haven't gotten that far on mine, BUT from what I've been reading the spacing and bolt pattern is the same for the 550 and 650. I also saw that using the 650 exhaust gaskets are better but I have a pair of each and they look exactly the same...

[Steve]

I am reasonably certain that the port diameters are the same, but check the bolt spacing on the collars.

Dogma and I ran into a similar problem with 850G/1000G pipes. He has a 1000G and had some 850 pipes to put on. I have an 850G and had some 1000 pipes to put on. They fit into the head, but the holes in the collars would have had to be slotted to fit the other size pipe. We fixed that by swapping exhaust systems.

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[tedk]

Thanks. I may be able to pick up a 4-1 550 header cheap and since 4-1 650 pipes are difficult to find or outrageous $$ & would be about as much as I paid for the entire bike and am pretty crafty - I may able to size these up and make useful. Don't want to waste my time if it is a known no-go.

[BigD_83]

There was a stock 550M header and pipe on my 650GD when I got it. It "sprung" a bit when taken off, and there was evidence that it hadn't been seated properly, but a PO may not have replaced the gaskets. It worked well enough until I replaced it with a new model-specific 4 into 1.

Before going to the BUB header, I made a brief attempt to use a set of aftermarket pipes made for the GL. The exhaust hangers needed to be modified for use on the G frame.

[tedk]

Big D, did you have to mess with fuel mixture much or just do the jets? Stock airbox? I have an E model, but not too much worried about mounting fabrication. Now I can't get in touch with the guy that has the exhaust. CL maddening!!!!!!

[BigD_83]

Ted,

I had a little bit of a lean condition with the stock airbox, so I upped the mains to what is listed in my sig. The highest idle/plug chop adjustments ended with the idle mix around 2 to 2 1/2 turns. Since then I have been struggling with it being slightly rich at lower engine speeds (ie rich idle) but I believe it related to a coil issue, not jetting. Even turning them back in to 1 1/2 turns has not fixed that completely.

I have mothballed the 650 for the winter as I have some cosmetic work coming up, and I have been away too often to justify insurance until March, but I will probably be dropping the main jets a size and checking the float heights one more time, in addition to giving the coil electrics another check, as the richness got worse as the temperatures started dropping.

[wegs426]

They are interchangeable. I have a Mac 4-1 on a 550 and no name 4-1 from a 650 and played around with fitting them to opposite heads.