After market exhaust

[Guest]

Hello everyone,
I have a 1980 gs 550 ,need new exhaust my question is there any aftermarket products out there that dosent require rejetting ? Im getting some conflicting info just thought id ask the experts

[Buffalo Bill]

I put a MAC 4-1 system on my GS550 and did not do any jetting, I think I shimmed the needles.

[Denman2112]

Thanks for the info,what is shimming the needles ?

[Joe Garfield]

Marving is showing some options for your bike. They're Italian but have a US distributor. I would think someting marketed for a specific model/year shouldn't require changes to the carb, but that is an assumption

http://en.marving.com/moto/gs-550-19781981-182.html?ricerca_effettuata=true

You might be able to find a stock exhaust in good shape, too, if you look around and post an ad in the Classifieds.

[Buffalo Bill]

Thanks for the info,what is shimming the needles ?

That is to put tiny washers on the jet needles to lift them a tiny amount, so while accelerating the carb pistons reach the narrow part of the needle sooner and run richer. Easier to do than changing to a larger jet size, and not quite as rich.

[Denman2112]

Thank You !!!!!!

[Steve]

Of course, you need to keep in mind that all bikes are just a little bit different, so what works for one bike might not work for another.

The only way to determine what YOUR bike needs is to do the modifications you want, then do some testing and see what YOUR spark plugs are telling you about what is happening inside YOUR engine. Adjust from there.

.

[Denman2112]

Thank you for the information