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Discussion Starter · #1 ·
I have a questions for those that have done the Holley mod.


should i have a set of OEM or k&n filters installed ???

i dont have any filters in and was wondering if this would cause the bike to run rich ???
 

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Discussion Starter · #3 ·
anybody have a set of filters they arnt using ???
 

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2007 Candy Sonoma Red
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They come with a foam filter, do you have that in them? Any filter is better than none. And it will run lean, not rich, without a filter.
 

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I would put a set of K&N's in as they breathe better.
I would not put the K and Ns in if you are running the supplied foam filters. That would make the engine breathe through two filters, not necessary. Thus it would not breathe better. And running either the Edelbrock or Holley with just the mesh and a K and N underneath would be too geeky for me. But whatever floats your boat.

I have been usnig the Edelbrock filters (same as Holleys, different pattern to the screen) for four years, not had an issue yet. Also I do know that Pep Boys sells replacement filters for the Edlebrocks, you could also use these in the Holleys. I do not know if Auto Zone, Advanced Auto, O'Reillys, etc., sell replacement filters, but they all sell the entire assemblies.
 

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Discussion Starter · #7 ·
HAHAHA...I have the foam filter in them. i was just wondering if the bike may be getting too much air and causing it to run rich.

im getting very poor mpg(83-87 before light comes on). and at idle i get a very strong oder of gas.
 

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HAHAHA...I have the foam filter in them. i was just wondering if the bike may be getting too much air and causing it to run rich.

im getting very poor mpg(83-87 before light comes on). and at idle i get a very strong oder of gas.
You have something backwards in your thinking.

Too much air equals lean.
Too little air equals rich.

Just about any filter you put on any vehicle will allow it to breathe better than the stock unit. There are some exceptions of course, but mostly if you put on a different set-up than stock, plan on it increasing airflow.

The generally held belief here at M109riders, is that you can change the filters and be okay. Or you can change the exhaust and be okay. If you change both, plan on doing something to increase fuel flow as it will be lean.

I have had Edelbrocks on my 109 for four years. I changed the exhaust out this weekend, to a Cobra Tri-oval. I never altered the fuel due to the thinking noted above. What I found when I removed the stock pipes is that the headpipes, where they mated to the engine, are totally ash white (lean) inside. I was not expecting this, yet it also appears to have done no harm in 14,000 miles of riding.

Now that I changed the exhaust, I added a TFI Fuel Injection Module, and richened the mixture accordingly. I am now getting some notable odor out the tailpipe, but that is partly because there is no catalytic converter in this pipe.

I cannot speculate on your poor mileage. I will tell you what mine was with just the Edelbrocks on. My wife and I rode from Oklahoma City, OK to Fort Smith, AR, via Interstate 40. When we stopped for gas, my odometer showed 192 miles. It took just about 4 gallons to top it off. Thats 48 mpg, which I find hard to believe. But, it-is-what-it-is, and I am sure that now that I have re-programmed the thing for the pipes, that will not happen again.

Evidently yours is running rich, for whatever reason. It should not be if you changed just the filters. You at a high altitude location? That would fatten your mixture, although the bikes computer should compensate for that, and temperature variations with ease.

But I can tell you that just putting Edelbrock or Holley filters on did not make it richer.
 

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Foam filters

I've been running the Holly foam filters (only) for years myself, and not damaged my engine. I don't see why some people think we need to add a K&N behind it as if the foam doesn't filter enough.
There is a "new" hot mod :dontknow: called a sleeper mod that uses foam filters directly on the throttle bodies. Seems like it's not such a new concept to me. Eliminating the air box just makes more noise as far as I can tell, and introduces hotter air. I think my "Tony mod" Holly based intake works just as well if not better.
I do think your bike as all our bikes will benefit from a fuel controller like my Cobra FI2000R, they are too lean from the factory.
 
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I also run the Edlebrock/Holley filter mod with just the supplied foam filters. They are made to filter adequatly for expensive high performance car motors that flow three times the air that our bikes do. And we're using 2 of them. I think they can handle our filtering and flow needs. I get great gas mileage, 45 to 50 mpg. So I think your problem lies elsewhere. You shouldn't be able to smell gas. And you aren't running too lean. This mod allows much cooler air into the airbox where the air temp sensors are. They react to that cooler air by richening up the mixture for the same airflow. But not so much that it would run rich either. There must be something else causing you to get poor mileage and smell gas.
 

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Gas odor at idle

HAHAHA...I have the foam filter in them. i was just wondering if the bike may be getting too much air and causing it to run rich.

im getting very poor mpg(83-87 before light comes on). and at idle i get a very strong oder of gas.
I just remembered why you get the smell at idle. I'll bet you smell it on the left side, yes?
With the Holly's, the crankcase fumes, hot oil and unburnt gas that get by the piston rings, are coming from the central airbox. You really smell it when the bike is hot, and you are idling at a stoplight. If you remove your gas tank, you'll see the breather hose that goes from the box behind the rear cylinder, up and into the right side of the big central air box. It blows these fumes to the left side, and right out the Holly filter.
Lots of us have rerouted this hose elsewhere with a small breather filter, catch can, or otherwise, out the back by the rear tire. Seal up the hole into the air box, and you won't smell it anymore. You also won't get oil on your airfilters if it pukes from an overfill.
This is the 1/2 inch id hose, not the 2 small vacuum hoses to the back of the air pods.
I did this so long ago, I forgot about it.
 
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