Exhaust odor while riding

[Vdriveboater]

The XII being my first touring style bike, I've not had the experience of so much wind being blocked and the feeling of the air coming around from behind me and pushing on my back. This is the sensation I'm getting, and unfortunately it's bringing with it exhaust gases, to the point where I'm pretty sure it's not a healthy situation to be constantly breathing that stuff. It does have an aftermarket windshield that's pretty good sized. I've seen some touring bikes with a small vent fitted into the center of the windshield that apparently allows air to come straight through and reduce the "backdraft" that I'm experiencing. Any ideas out there?

[GrandpaDenny]

The XII being my first touring style bike, I've not had the experience of so much wind being blocked and the feeling of the air coming around from behind me and pushing on my back. This is the sensation I'm getting, and unfortunately it's bringing with it exhaust gases, to the point where I'm pretty sure it's not a healthy situation to be constantly breathing that stuff. It does have an aftermarket windshield that's pretty good sized. I've seen some touring bikes with a small vent fitted into the center of the windshield that apparently allows air to come straight through and reduce the "backdraft" that I'm experiencing. Any ideas out there?

There are vents in the fairing that serve the same purpose. The upper vents are next to the speakers. Do you have them open? It doesn't cure all of the "wind from behind" feeling (that still feels wierd to me after 50k miles of daily riding), but helps some. If you smell exhaust, then you have a problem somewhere. Check the usual tune-up stuff - plugs, filters, etc. These are not normally "stinky" bikes. You might smell some gas occasionally, as with probably any carbureted bike, especially right after filling up. I'm going to guess that's probably what you're smelling. Don't fill the tank too full, and try not to spill any. First click on the pump (usually - YMMV with inconsistent gas pumps and nozzles). Fuel level should be just below the flat area you can easily see through the fill hole.

[Vdriveboater]

Thanks for the reply Denny. Actually I did recently fill the tank but I don't think I overfilled it. To be clear, the fumes are burned exhaust vs unburned gas. As I've mentioned in a different post, I did clean and rebuild the carbs and discovered that the #1 and #2 fuel mixture screws were screwed in all the way, and #3 and #4 were 1.5 turns out, which helped to explain why it wouldn't start cold without starting fluid and would idle erratically (along with clogged pilot jets). I set them up at 2.25 turns out after the rebuild. At the first start up I adjusted the idle knob up and after getting her up to temp I realized it was less smooth at idle than when I first started it, so I attempted to turn each mixture screw in about a quarter turn using the HF 90 degree ratchet screwdriver. Unfortunately that tool's ratchet requires too much force to move tooth to tooth, turning the mixture screw with it, so it's quite possible that the mixture screws aren't accurately set. A week ago I ordered one of those special "pilot jet adjustment tools" from Fleabay that is nice and long that turns the screw driver remotely as you twist the handle. Once I get that I can fine tune it for sure. The exhaust fumes are quite noticeable at a steady 55-60 mph -- are those fuel mixture screws (the ones at the bottom front of the carb) affecting operation at those speeds? I don't recall the exhaust fumes when I test drove the bike, which had the super lean screw settings, along with three pilot jets that appeared to be plugged. And yes, I've opened all four of those vents in the fairing.

[GrandpaDenny]

I think you might need the assistance of an exhaust gas analyser to get the mixtures right. Then after you do that, synchronize the carbs. What's the method we used to use on cars back before they became rolling computers? Adjust for best idle then lean out slightly? Or on even older cars, just adjust for best idle. Wasn't that it? Is that feasible on multiple carb setups?

[Vdriveboater]

I agree Denny, that makes good sense. I'll have to ask my local non-franchised bike shop if they have that capability. Last night I was able to verify the mixture screw turns by hand, just using the screwdriver bit and my fingers, so they're all about 2 turns out. Then I tried turning each one in and out slightly but I couldn't perceive any change in idle. I'm wondering if there could be a float level issue? No gas has run out of the overflows on the carb and I see no sign of black smoke. What I do plan to do tomorrow morning is pull the plugs (which have maybe 100 miles on them) to see how they look. I just removed the front and rear wheels and dropped them off with new Shinko Touring tires to the Kaw dealer to change them out (old tires were date coded year 2000). Based on how much tread was on the rear, it's obvious the bike has not been ridden much over the past 20+ years. I took the wife for her first ride on it yesterday and she said she was falling asleep and wants to be strapped in so she doesn't fall off!! We both wore full faced helmets and I noticed the exhaust fumes were less noticeable, which could have been the result of getting all mixture screws at two turns (the #3 screw was almost at 3 turns), so that's progess.

[Vdriveboater]

I agree Denny, that makes good sense. I'll have to ask my local non-franchised bike shop if they have that capability. Last night I was able to verify the mixture screw turns by hand, just using the screwdriver bit and my fingers, so they're all about 2 turns out. Then I tried turning each one in and out slightly but I couldn't perceive any change in idle. I'm wondering if there could be a float level issue? No gas has run out of the overflows on the carb and I see no sign of black smoke. What I do plan to do tomorrow morning is pull the plugs (which have maybe 100 miles on them) to see how they look. I just removed the front and rear wheels and dropped them off with new Shinko Touring tires to the Kaw dealer to change them out (old tires were date coded year 2000). Based on how much tread was on the rear, it's obvious the bike has not been ridden much over the past 20+ years. I took the wife for her first ride on it yesterday and she said she was falling asleep and wants to be strapped in so she doesn't fall off!! We both wore full faced helmets and I noticed the exhaust fumes were less noticeable, which could have been the result of getting all mixture screws at two turns (the #2 screw was almost at 3 turns), so that's progess.

[Vdriveboater]

Update: plugs are clean (not dark/black), no visible exhaust fumes, runs strong and clean from 1500 to 5000rpm, idles smoothly. I reduced the turns on the fuel mix screws to 1.5 on all carbs with no negative impact at idle or low speeds. Local auto service shop owner checked for exhaust leaks on all four pipes with a stethescope from the cylinder to the outlets with no leaks found (and I did the sniff test through the side fairing ducts with no fumes detected). We both concluded that the fumes are likely being "sucked" from behind and pulled forward due to the fairing and windshield (slipstream). It would seem that almost everyone with a Voyager XII would be experiencing what I am. Other than the windshield, the bike is totally stock. We're thinking that the location of the exhaust outlets being in front of the back of the bike (rather than behind it) could be a major contributor, since this would allow the fumes to be pulled into the "vortex" and up into the rider area. My wife smells nothing because her head is above the windshield which gets the fresh air blast from the front. This one is a real head scratcher . . . . .