geezer glide Posted March 29, 2008 Share #1 Posted March 29, 2008 Does anybody out there have the specs for air box mod for going to a K&N filter on 1st gen? have an 87 royale that i want to put a K&N in. bought with somewhat modified air box. dont know what the original air box is supposed to look like inside and has holes drilled in top of outside. if anyone has an idea of what i need to do to make it right please help..lol..thanks. riding season coming soon!!!!! Link to comment Share on other sites More sharing options...
Rick Butler Posted March 29, 2008 Share #2 Posted March 29, 2008 Jason, If your air box has 4 - 1/2" holes, one drilled in each outside corner of the top cover, you are alright. But if it has more holes, larger holes, or holes drilled in the body I would to need more information about these holes before I could give you any more advice. Rick Link to comment Share on other sites More sharing options...
geezer glide Posted March 29, 2008 Author Share #3 Posted March 29, 2008 Rick, thanks for replying....here are some pics of my air box. have suspect bike has been rejetted due to running very rich. fuel eco is great..power is good, just seems to run a little rich. old paper filter got dirty came with K&N, thought i would put it in. any help would be greatly appreciated....thanks! http://img.photobucket.com/albums/v604/mnharley/DSCF4685.jpg http://img.photobucket.com/albums/v604/mnharley/DSCF4686.jpg http://img.photobucket.com/albums/v604/mnharley/DSCF4687.jpg http://img.photobucket.com/albums/v604/mnharley/DSCF4688.jpg http://img.photobucket.com/albums/v604/mnharley/DSCF4689.jpg Link to comment Share on other sites More sharing options...
Condor Posted March 29, 2008 Share #4 Posted March 29, 2008 When I got the '91 home and had a chance to pop the hood I found the top of an air box that looked like a piece of swiss cheese.... with a K&N filter. The thing ran a little rough when I first looked at it, and thought it needed a good sync and plugs, but I slapped on another box top and it smoothed right out. Pitched the holey one into the trash. I also run a K&N filter on the '83 and '87. Never found a need to punch holes in them either. Link to comment Share on other sites More sharing options...
Rick Butler Posted March 29, 2008 Share #5 Posted March 29, 2008 Jason, So you say that your bike came with the air box this open? And it runs good with decent mileage and you think it's running rich? What do the intakes under the carbs look like. I would guess that this is a box that has been modified for a Tuggs induction or DynoJet V-Boost kit. Or maybe someone who has installed V-Max intakes with a solid cross-over. And if so, the mains are probably 150s instead of 125s. Regardless, the K&N filter will work just fine without any changes. But if this box is on a stock bike, the top needs changed out. In fact I think I have a stock lid laying around my storage somewhere. But get us a picture of the intakes, to satisfy my curiousity, Rick Link to comment Share on other sites More sharing options...
geezer glide Posted March 29, 2008 Author Share #6 Posted March 29, 2008 here's some more pics of my carbs set up. not real sure what you mean when you say solid cross over. ive heard of being able to put v max top end on this motor. dont believe this was done but not sure. holes in the air box were taped shut with duct tape. exhaust loads up (popping) collector has been opened previously. like i said, bike came with bag of goodies including K&N, just thought i would install it- found block of swiss cheese for filter top. thanks for response... http://img.photobucket.com/albums/v604/mnharley/DSCF4693.jpg http://img.photobucket.com/albums/v604/mnharley/DSCF4690.jpg http://img.photobucket.com/albums/v604/mnharley/DSCF4694.jpg hope these help Link to comment Share on other sites More sharing options...
Rick Butler Posted March 29, 2008 Share #7 Posted March 29, 2008 Yeah Jason, Your carbs look to be stock. But I see that maybe the diaphrams may have been changed out because the bolts in the diaphram covers have been changed out. So like Condor suggested, you need to pitch the cover and get a stock one. And if you want to pay the postage from Dallas, TX, I'll send you one that I have had laying around from my early Gen 1 days. Rick Link to comment Share on other sites More sharing options...
Condor Posted March 29, 2008 Share #8 Posted March 29, 2008 Looks pretty clean in there, but from the pic it looks like #1 manifold clamp is missing?? Link to comment Share on other sites More sharing options...
Gearhead Posted March 31, 2008 Share #9 Posted March 31, 2008 If I understand correctly... Jason, you said holes were taped shut. Somebody probably got the idea to open the airbox and went crazy, then found that the bike didn't run worth a hoot. Thses bikes are tuned such that they are very sensitive to the airbox configuration. Try to run it while holding the filter in place but with the cover off. It will idle but won't take any throttle or rev up. I've never seen anything quite like it. Like Rick said, up to (4) 1/2" holes works fine, although I'm not sure if there's any benefit. More than that and you're courting trouble. Did you say the stock mufflers have been opened up? As in, your bike makes more exhaust noise than average? That will cause popping, or actually allow it to be heard. I think popping on overrun always happens, but stock exhaust keeps it very quiet. Aftermarket pipes typically allow the popping sound on overrun. How do your plugs look? Jeremy Link to comment Share on other sites More sharing options...
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