89 exciter exhaust pop when idling down

[fuzznutz]

I'm new to the forums but have been looking around here for some time. Can't seem to find an exact answer to my question so decided to ask. Getting a series of pops when letting of the throttle and it doesn't return to idle consistently, will kind of hang out at 3k for a few secs then drop to 1500 and idle smooth from there. Plugs indicate a rich mixture, but haven't fouled any. It seems to consume a lot of fuel, maybe 8mpg bombing around pulling sleds etc. I bought it a month ago and would barely idle and do nothing else, removed and cleaned carbs,jets etc, removed auto lube and mix now due to over oiling, mixing at 45:1 ratio running 87 octane. It runs great, no hesitation at any temp and seems to have a lot of power, will wind up to 7800 rpm no prob.125 comp both holes. It has a phazer primary clutch, engages at 4k seems a little high. Is the popping normal? Will it hurt any thing? There is a small crack in the stock pipe at the 2nd bend, there was a hole that we welded but still peals a tiny bit. Is this a serious problem? Any info,input, advice I would love, this is all new to me again, haven't had a sled since 1985. This Exciter is in near mint condition with 4500 miles. Thanks, fuzz.

 

[NB-Snowgoer]

You should fix the crack in your exhaust first before checking anything else, it maybe the cause of your popping noise.

 

[theo125]

I agree I think the crack might be the cause.
As far as your engagement goes my 89 exciter kicks in around 3800 so you are not that far off.

 

[fuzznutz]

Thanks for the replies, just to clarify I hear the popping in the y before the pipe, no sound coming from the crack, and not a backfire out the pipe, or lean cough in the carbs. It is just a little wet in that one spot on the pipe which tells me it is leaking a little. What kind of mileage are you getting? Does 8 seem low?

 

[theo125]

OK-I gotcha now. Mine was leaking out between the Y and pipe. It might be a redneck fix but I separated the pieces and put a bead of the copper high heat gasket maker between and put the springs back on. After it sat overnight I hit it with some black paint so it is not noticeable. I did not look at the microfiche, but I imagine there is some sort of copper gasket or something that goes in between.

 

[fuzznutz]

Doesn't appear to be leaking there, the POP is within the pipe, maybe I am worried for nothing. For its size it sure puts out ponies, maybe its just a normal thing on these engines. I may try the copper sealer any way, good idea, and get the weld to stop leaking. Is there more info to be found regarding this vintage Exciter? I have the clymer manual, very helpful. Is there a forum strictly for these some where?

 

[theo125]

I wish there was. The guys on here are extremely sharp. Do a search and if you keep hunting, most likely you will find it.
Is your pipe stock? I had a gutted pipe that was on when I bought and it was quite loud and poppy. Did nothing but scare the kids : )
I put the stock back on and quieted it down and actually ran better.
Maybe someone gutted your pipe along the way-just a thought.

 

[fuzznutz]

Learned today that the POP is more than likely unburned fuel igniting in the pipe due to a rich condition, confirmed by the plugs and fuel mileage. Surprised I'm not fouling any plugs. Thought I would post the info. And it is the stock pipe, doesn't appear to be gutted.
Wanted to be sure it wasn't a lean pop, deathly scared of a burn down. Will keep tweaking those carbs till its right. I Love that silly old sled, really moves for its age.