High Altitude W/O Air Filter


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bfvc702
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High Altitude W/O Air Filter

Postby bfvc702 » Sun Aug 04, 2013 7:10 pm



Please don't beat me up over this post!

I've posted before about high altitude (6000-10000) riding with my '83 GL1100. I understand the physics involved and possible remedies. However, it just does not seem right that climbing a moderate grade with full throttle that the engine feels that it is missing ignition and stutters which does not happen at lower altitudes. This afternoon, I took out the OEM paper filter and even though the power loss was still there it seemed to run more consistently than with it. So, I would assume that it was due to increased air flow.

I did modify the spark plugs and that helped some, but not as much as removing the filter. Re-checked valves, all good. Fuel flow should not be a problem since plugs show rich.

So, realistically, what is the ominous down-side of selective riding without the air filter? I'm not riding through dust storms in the mountains! Would a K&N provide that much increase in air flow? Any other alternatives? I haven't really been convinced that re-jetting or pilot adjusting would make much difference.

Any thoughts?



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redial
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Re: High Altitude W/O Air Filter

Postby redial » Sun Aug 04, 2013 10:31 pm

It is not only dust that you are trying to protect from, dont your bugs, mosquitoes, flies, bees et al fly at those altitudes. The last thing I would be doing is removing any of the filters: air, oil, fuel - you dont need them, until you need them.

As for riding at altitude, if you do it consistently, then you may have to tune the GW for altitude riding.
Len in Kapunda

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SteveB123
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Re: High Altitude W/O Air Filter

Postby SteveB123 » Mon Aug 05, 2013 8:38 am

bfvc702 wrote:
I understand the physics involved and possible remedies. ? I haven't really been convinced that re-jetting or pilot adjusting would make much difference.

Any thoughts?


You don't think changing the fuel-air mixture (jetting) will affect performance, but you claim that changing the fuel-air mixture (increased airflow from filter removal) affects performance?

Maybe just downshift, if you're going full throttle uphill in the mountains.
Current:82 GL1100 Interstate, 60 Amp Poorboy, MSD coil
Previous: 93 GSX1100F Katana
82 GL500 Silverwing

bfvc702
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Joined: Wed Sep 15, 2010 2:16 pm
Location: Bloomfield, NM
Motorcycle: 1983 GL 1100

Re: High Altitude W/O Air Filter

Postby bfvc702 » Mon Aug 05, 2013 9:24 am

I am down shifting. Sometimes to third gear to stay at 50 mph on a 65 mph posted roadway. Also re-jetting requires pulling the carbs which I don't wish to do in the middle of the riding season. I've read what is required to adjust the pilots and that seems to be a chore with the carbs on.

Also, since I ride from 5000 to 10000 regularly, I'm looking for a temporary but useful solution. Adjusting the fuel in the ratio leaves me in the position of lean at the lower elevations.

How about a cloth mesh of some sort stretched across the top of the air filter box with the top holding it in place?

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dingdong
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Re: High Altitude W/O Air Filter

Postby dingdong » Mon Aug 05, 2013 2:27 pm

It's your bike do what you want. The mountains for some reason have been very dry and dusty every time I have been there. I would at the very least try the K&N filter. Adjusting the pilot screws isn't going to help either. Something is wrong with the fuel, air, spark combination on "your" bike. You shouldn't have to re-jet for those elevations. There are many 1100s that pull the mountains just fine. My first Goldwing was an 83 1100i. I rode the mountains many times out West with no problems. Keep in mind that the 83 has a different gearing than the earlier 1100s. 5th gear is considered overdrive on that bike.
Tom

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SteveB123
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Re: High Altitude W/O Air Filter

Postby SteveB123 » Mon Aug 05, 2013 3:01 pm

It would have to be an awfully open cloth to have less restriction than a regular element.

Plug showing rich can also be an ignition system showing weak...altitude gives a "wrong" mixture, which is harder to ignite.

Coils, wires, caps reasonably fresh?
Current:82 GL1100 Interstate, 60 Amp Poorboy, MSD coil
Previous: 93 GSX1100F Katana
82 GL500 Silverwing

bfvc702
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Re: High Altitude W/O Air Filter

Postby bfvc702 » Mon Aug 05, 2013 5:03 pm

Now there's a constructive suggestion that makes sense given what I've been experiencing! Will be pursuing that one. Thanks

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eklimek
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Re: High Altitude W/O Air Filter

Postby eklimek » Mon Aug 05, 2013 6:37 pm

Recorded voltage reading when you are obliged to downshift at altitude? Is it fuel mixture or poor spark?

bfvc702
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OMG, AIR Matters!

Postby bfvc702 » Sat Aug 17, 2013 6:51 pm

So, I replaced my paper air filter with a K&N today. What a diff! Road from Durango over to Ouray. Start at 6500' and climb three passes at 10000' +-. Most of the ride is climbing up and going down the passes. I had throttle! Yes, I have to down-shift and speed is limited on the high altitude inclines, but I could get full throttle in all gears without that stalling/bogging-down response.

Very happy. But, disappointed that the paper air filter did not perform. It only has less than 1000 miles on it.

I'm glad I tried riding without it, otherwise, God only knows where my efforts would have taken me to solve the problem.

I guess a lesson re-learned. KISS (Keep it simple stupid}, when it comes to searching for the answer.

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bstig60
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Re: High Altitude W/O Air Filter

Postby bstig60 » Sat Aug 24, 2013 1:57 pm

Another thing that can affect power output is Compression....... Have you checked it lately?
Bill

bfvc702
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Re: High Altitude W/O Air Filter

Postby bfvc702 » Sat Aug 24, 2013 4:26 pm

Not since last year. I don't remember the numbers, but all cylinders were about equal and within a range that one would expect for 6500'. However, that fix would not be desirable in the middle of the riding season. I think the new air filter will be sufficient for now.




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