Delkevic downpipes for a GS850G

Or most of it...
Delko downpipes, £170

But, they wanted another £135 quid for a muffler, so I went the way I've gone previously and got this to go on it...

A Hardly unused take-off from a Fat Bloke or something.
For a mere £25 and the cost of making a link pipe.
It will respond to my diy decibel killer if it has to.

 

Well, a year on and the Hardle muffler is doing a great job.
I finally got the GS back on the road around April and ran it in carefully like a bat out of hell.
Actually, there was something I'd been meaning to re-try for ages, but lack of engines to be rebuilt had kind of cramped it.
This time around I assembled barrels onto the pistons dry.
Yep - no oil.
Carried on doing the build as normal, but when everything was ready to turn over, I carefully turned the engine over with the crankshaft nut for about six revolutions slowly. Then I drenched the cylinders with a few shots of oil out of the oil can, and carried on as normal.
I'd heard about this method thirty years ago and had seen it done quite successfully too, then I'd built a small engine doing it that way with good results. That was the only previous one I'd done and I was sure I was doing it right. Several subsequent engines I'd built were on company time, so I was unable to run the risk of doing it that way again.
I'd described this method to a friend of mine but he got in a huff when his piston rings got all twisted up. Silly sod had fired it up still dry.

Anyway, back to the muffler...
The first few hundred miles there was an annoying blat coming from the pipe, and on taking it apart I realised that I'd accidentally created an uncontrolled resonance chamber between the front of the collector and the start of the baffle chamber in the Hardly muffler. There was also a flat wall at the start of the baffle box, which was probably the main source of the noise.
This noise started at 4500rpm and got steadily louder and vibier as revs increased, which was not just annoying but giving rise to a fair degree of mechanical vibration which wasn't doing the engine any favours.
So, I took a look at the bits I'd taken out of the muffler and realised that the Harley designers probably knew what they were doing - ahah... There was a conical-shaped piece of tube that I could reverse and weld onto the inlet of the baffle pipe, so doing away with the sharp flat front to the baffle pipe.
I also put in a couple of stainless steel pot scrubbers - the really coarse type - just to be sure.
Success! The annoying blat has gone and the pipe now sounds much more liveable with. It's still loud enough to have a touch of non-stock about it but really shouldn't bug anyone.

Oh, yes; the follow-up to the dry build - perfect ring seals, excellent compressions and not a trace of oil.

 

Today I made a better exhaust noise.







[video=youtube_share;arWw0e-Bq3U]

 

Finally got around to fitting the proper Delkevic silencer, after I'd sussed out that there was a dome segment inside it that broke up the interfering pulse that was bugging me.
It works quite well, running quite smoothly now and sounds really good, but it's too loud.
I'm going to try adding an end piece from a Supertrapp to see if I can tame the racket a bit.

 

I like that Dave, I will have to try the same on my next rusted out exhaust. Thanks for sharing.

 

Sounds like my old gs750 with a Marving 4-1. Nice.

 

Got the Supertrapp end piece fitted a couple of weeks ago and discovered that it didn't do much for the raucousness of the pipery, so took out half the discs, leaving six or so in place. Now that made a difference. It's a fair bit quieter, but I notice it's not passing gas as well as it did before.
Ragging it up the by-pass didn't feel quite as quick off the mark when it was more-or-less unhindered.
The AFR gauge is behaving itself, so still need a bit of jiggering around with it.