Custom exhaust question

[rphillips]

Years ago, I purchased a V&H 4 into 1 for my GS 1100 E. It came with either 2 or 3 restrictors, that fit in the collector. The smallest restrictor would give more bottom end power, & less top end power. With no restrictor, it would have more top end power, & much less bottom end. Also retarding the cams a few degrees will give more bottom end, but you will give up a little on the top.

[rickt]

Rusty exhaust making me nervous

When I removed the exhaust system from the '78 GS750 that I was given (and I currently restoring), I noticed a significant pile of rust that fell out of each pipe and muffler. THe pipes and mufflers are in decent condition as the bike had a mere 2000 miles on it when it was parked in 1981. I was thinking of pulling some coarse steel wool through the pipes and trying to use them, but these posts about rust dust being pulled into the cylinders has made me a little nervous. Should I dump the old exhaust and pull out the checkbook to buy an entirely new exhaust system?

Please give me some advice.

rickt

My issue with aftermarket exhausts are the noise and the rust. Rust that forms on the inside of the pipes can be sucked back into the engine with the reverse power pulses - the particles will then cause ring/cylinder wear. Not good. The factory systems rust also but typically further downstream in the system so I think they are less likely to make it into the engine. At any rate, that's my $0.02. Reusing the factory head pipes but fashioning some sort of high quality mufflers would be a good way to go.[/quote]

[themess]

20+ years ago, Cycle put a Kawasaki on the dyno, with about ten different exhaust systems. They tested the OEM system, and after market systems that were mostly made by major companies like Jardine and Kerker. They found that not only was the stock system the quietest, it also had the best compromise of power over the RPM range. I don't remember what they did to readjust the carbs with each exhaust system.

So it seems to me, that unless you have a specific performance goal in mind, trying to duplicate the stock system as closely as possible would make sense.