GS1100G Popping on Overrun

[salty_monk]

The 82 is up and running! Put the first 25 odd miles on it. It runs great! Plenty of power, pulls in every gear etc. On overrun when you let the throttle off or run downhill with no throttle (also sometimes on a barely cracked throttle) I get some popping through the pipe which has improved a bit over the mileage.

The Carbs I believe are stock apart from the screws being opened up to about 3-3.5 turns (best rpm idle method).

I have had an issue of number 4 not firing at idle so I suspect a partially blocked pilot jet which I believe is now cleared as it's idling great & performing great on the road. Still a bit less color on that pipe though.

I have a decent slug of seafoam in this tank, I wonder if like a 2 stroke with too much oil in that makes it run a little leaner...

Bike has a delkevic 4:1 and a Uni filter in the box (should be very similar to stock foam filter).

No chance of air leaks as it's had new rubber bits all round. including both new intake boots & airbox boots (although I did re-use the clamps, they seemed fine). This engine had new rings & stem seals and all new gaskets.

Just looking for some ideas... my primary idea is to run some more tanks of gas through it & see how it develops before I do anything but if anyone has suggestions (raise the needle a bit, use a bigger pilot jet, stop being lazy & pull the carbs to clean number 4 again...) then I'm open to them!

 

[TxGSrider]

Are you running the baffle in the exhaust?

 

[Buffalo Bill]

Switch the plug wires between 4 and 1, as a test.
Pull the carbs and check.
Check the valve clearances, and compression.
The Gunson Colortune is EZ to use on the 1100G.

 

[rphillips]

25 mi. ain't much. If a possible pilot problem, how about giving the Seafoam a little longer to possibly do it's thing. Would be a shame to dig in to it, if a little more run time would have cured the problem. Just my opinion.

 

[salty_monk]

Looks like you're thinking along the same lines as me... I've had worse clear on bikes that haven't been ridden before. I had a friend who'd regularly leave his bike for 3-6 months at a time then jump start it & ride it with a full pot of "gum-out" in the tank to clear it. The first 3 miles were an absolute pain but it would get better & better as you rode...

Bill - good idea on the plug wire switch. I am getting good spark to number 4 however so I doubt it's that. I even put a spare plug in the wire when it was running on 3 to check that spark was present....

Compression - should be going up... new rings, still seating. Valves are in spec. Bike had a top end refresh.



I have a colortune, I think I've only used it once, maybe I'll give it a go.

 

[Guest]

my understanding (perhaps mistaken??) is the colortune doesn't work as well with cv carbs. Exhaust bolts/studs tight? mine will pop more when i have a little leak there..

 

[Guest]

Any place where the exhaust system connects, you can have a ever so slightly gap there. That can cause the popping. Mine pops from where the mega phone mates up with the collector ( mine is an RC pipe). It sucks in some cold air there when I let off the throttle, does it to just running down a hill with out any throttle. I've stopped it some by using an exhaust expander inside the collector to make a tighter fit. And if I'm right your Delkevic came in separate pieces, mega phone, collector and separated pipes. Lots of connections there. Oh and not to mention new exhaust seals.

 

[salty_monk]

Yep, that was my first thought too Greg. Torqued to spec though & I used new OEM gaskets.

I guess there could be a leak where the head pipes fit into the collector or where the muffler joins on the pipe.. Bill. I used their supplied sealant (RTV basically) so it should be ok but still possible, it sounds similar to what you experience.

 

[kochic]

My Delkevic popped like you describe, probably because of the heavy gauge header.The baffle is all metal for memory and the sound is more ''tin can'' than my V&H or Bassani.
I did not used the Silicone sealant, everything fit perfect and I have no leaking.
I switched back to the Bassani after a test ride of maybe 30 miles.
My Delkevic is the straight system.
Marc

 

[salty_monk]

Ok, maybe just the way it's going to be then.... It sounds ok so far & I don't get any weird pulsing. Little louder than I'd like though.

 

[Grimly]

I miss the over-run crackle and pop from my previous Motad system. Lovely racket when wound up and back down again under load.
It did help that a 1/2" chisel was whacked through the baffle about 30 years ago.

 

[kochic]

Ok, maybe just the way it's going to be then.... It sounds ok so far & I don't get any weird pulsing. Little louder than I'd like though.

Good new for you for the offbeat pulse.
This is the only reason why the Delkevic is not on my GS.
Marc

 

[Buffalo Bill]

Ok, maybe just the way it's going to be then.... It sounds ok so far & I don't get any weird pulsing. Little louder than I'd like though.

I ordered the straight muffler system instead of the megaphone system, I got sucked into it because the straight is 2lb lighter. Like that's a biggie.
The description of the megaphone muffler implies that it's a bit quieter, but probably not much if any.
I ordered a Chinese made universal inner baffle "DB killer", hoping that would reduce the shock wave and lower the crackle at least.
In this system I'll fit it where the collector meets the muffler.
For $5 it's a cheap experiment.

 

[salty_monk]

Yeah I chose the straight just because I preferred the look... Be interesting to hear what your $5 does!

Before polish and badges by salty_monk, on Flickr

GS1100G Delkovic by salty_monk, on Flickr

 

[rphillips]

Looks like very little room for fiberglass packing on that baffle, but every little bit helps.

 

[salty_monk]

The answer to this seems to be to make the pilot circuit richer. Winding the screws out a full turn on each carb seems to have helped

 

[Simmons1]

I am checking in on this thread to see if the decel popping has been fully cured? I put 30 miles on my old GS1000s this morning. First ride in 17 years. It pops a lot on decel. When I redid the bike I replaced the old V&H 4-1 with stock air box with a Delkevic and Pods. When I had the carbs rebuilt by WiredGeorge, I let him know I would be using Pods and the Delkevic.

How many turns out do you have the pilot screws?

Thanks

 

[salty_monk]

I don't know how far out they are to be honest but at least 2.5 turns... and yes 500 miles later it hasn't come back

It's going to be different for you... you have pods. Yours should be at least 3.5 turns out in my experience & at that point you are likely at their limit. Any more would need a bigger pilot jet.

 

[Simmons1]

Thanks I'll give it a shot, and see what happens. I'll report back what I find.

 

[allojohn]

Thanks I'll give it a shot, and see what happens. I'll report back what I find.

Hold on a minute, you have VM's and Salty's 1100G has CV carbs - not comparable at all...