Engine issue plus looking for new exhaust

[thewoodman]

I have two issues it seems.

1) On a 4 day trip around mid-Florida this past weekend, I had an interesting throttle issue crop up. Some background history might help with diagnosis. For the past few months, my ear has detected a slight exhaust note change: as if one cylinder was not firing correctly; maybe a bad plug, or a bad spark plug wire. Subtle with no noticeable performance decline. New wires are on order and a compression check found nothing concerning. Though I don't recall the exact result, there was no more than 5 psi difference. 180-185 I think I remember.

So, this past weekend, on a slow gear change, the engine actually revved higher between gears and wouldn't slow back down from there. It now idles at about 1,200 RPM which is 400 RPM higher than set. It has a strange exhaust note at idle and almost a backfire pop on deceleration. With grump not with us any longer, I'm asking for opinions and directions on how to narrow down the diagnosis. Any thoughts out there?

Also:

2) I need a new exhaust system since I found a hole in the front left header pipe and unless I can patch it, it's time for new pipes for the old girl. At 24 years old and with
115k miles. I guess it's time. So, if anyone out there knows of a decent set of relatively unmolested stock pipes, please keep me posted.

[rug_burn]

   Sounds like an intake leak, from both the backfire on decel and the increase in idle speed.  
   First thing I'd check are the o-rings at the base of the carb-to-head intake runners.   (They're -122 or -123 [inch size] Nitrile material o-rings).  
    Also, the small vacuum lines going to the back of those tubes could be the source of the leak.    If you've never replaced either of those things, it's definitely time.    Nitrile rubber gets damn near rock-hard after about 20 years...

[muscrat]

I have a complete stock exhaust off of my 97 Standard, chrome is in excellent condition, some surface rust on the header pipes that I'm in the process of removing. They came off the bike when I bought it about 6 years ago and have always been inside. Down side is these things are HEAVY re shipping costs.
I'm in Southern  Ontario, Canada, approximately 30 minutes from Detroit, Mich.

Let me know if you have any interest with a fair offer, can send pics.

muscrat

[The emperor has no clothes]

I have two issues it seems.

1) On a 4 day trip around mid-Florida this past weekend, I had an interesting throttle issue crop up. Some background history might help with diagnosis. For the past few months, my ear has detected a slight exhaust note change: as if one cylinder was not firing correctly; maybe a bad plug, or a bad spark plug wire. Subtle with no noticeable performance decline. New wires are on order and a compression check found nothing concerning. Though I don't recall the exact result, there was no more than 5 psi difference. 180-185 I think I remember.

So, this past weekend, on a slow gear change, the engine actually revved higher between gears and wouldn't slow back down from there. It now idles at about 1,200 RPM which is 400 RPM higher than set. It has a strange exhaust note at idle and almost a backfire pop on deceleration. With grump not with us any longer, I'm asking for opinions and directions on how to narrow down the diagnosis. Any thoughts out there?

Also:

2) I need a new exhaust system since I found a hole in the front left header pipe and unless I can patch it, it's time for new pipes for the old girl. At 24 years old and with
115k miles. I guess it's time. So, if anyone out there knows of a decent set of relatively unmolested stock pipes, please keep me posted.

OEM pipes are double wall. Yours probably isn’t thru both header tubes.