Exaust & jetting questions

[tomo]

I`ve been spending my time in lockdown trying to get my 79 GS750 tidied up and back on the road after a long time sat in the garage. I stripped her right down and have rebuilt, not as well as I would have liked as plenty of time of course but a very limited budget. Anyway, the old exhaust was a 4 into 1 but of unknown make, possibly a Motad. It practically fell apart it was so rotten. So I had to bite the bullet and buy a new one, only one I could find for the bike was a Delkevic 4 into 1, which has a straight silencer on it. The bike started up great but I haven't been able to take it for a spin yet, so just warmed it up really. Noticed that the header pipes have started to turn that gold colour. I am not sure whether that is just because they are single skin, but suspect more likely it is running lean. Have to admit I have not replaced the intake rubbers or airbox rubbers, can`t afford to just now as apart from the exhaust had to buy new rear shocks, brake pistons and seals (haven't told the wife about those yet !) but will at a later date. So could be air leakage there although I have used plenty of sealant around the joints, weatherstripped the air box covers etc. As I said though, have not been able to take the bike out for a good run, only had the engine running on the drive and didn't rev more than about 1500rpm. I haven't touched the carbs yet other than cleaning, the pilot airscrews are out about 1 1/4 turns, Just wondering whether anyone else has the same exhaust fitted ?. Thinking maybe I need to lift the carb needles up a notch or two. Any advice or thoughts much appreciated.

[Rob S.]

Thinking maybe I need to lift the carb needles up a notch or two.

I wouldn't go fixing it before you know It's broken. Aside from trailer queens, I can't remember seeing a chromed header that didn't have some discoloration near the engine.

Besides, exhaust changes alone rarely require rejetting.

[Grimly]

Delko stainless pipes turn golden, fact.
I've been running mine with an AFR gauge hooked up, so I know it's not been lean.

[tomo]

Thanks guys, put my mind at ease a bit !. I had also forgotten to use the search feature, so just after I posted typed in Delkevic exhaust, quite a lot of posts and info came up. Looks like the pipes are ok to fit without messing with the needles or jets provided standard airbox is on, also that the gold is like Grimly says to be expected.