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Specter Air filter MOD


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Hey everyone.

 

I didnt see any posts about air filter mods (maybe im just lazy and near sighted) but, I decided after realizing that my running rich and afterfireing is likley due to my air filter looking like the original from 1983 and having the airflow (or lack there of) to match.

I'm sure you all know its kinda hard to find these filters and there are a few DIY tricks to keep the case and replace just the filter medium. Which was the route I was going to go until I remembered that I have 3D printer!!! (insert evil laugh here).

 

So I am going to create an addapter that replaced the little coupling inside the airbox to accept a specter cone air filter. I will update this post as soon as I have it printed out and tested, after which of course I would me more than happy to sell them out to eveyone here.

 

Wish me luck!

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The real battle you will encounter is getting the right amount of restriction in the airflow to match the stock flow! Have you even tried to find a replacement stock element? I may be wrong but they should still be available. A semi-popular mod several years ago involved four of those mini filters on top of each carb but you had to incorporate a restrictor disc that reduced the air intake opening on the top of the carbs to get the airflow proper for the right mixture...

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I have looked and K&N does have a replacement for $81. And need to be special ordered. It would be nice to have the ability to go to the local parts shop for such a simple part.

 

Given the air restriction requirement (does anyone know the exact mesurment for that?), I would think the extra air flow from a K&N might mess things up anyways??

 

I have 2 specter air filters I'm looking at now. One is slightly smaller in surface area so I think the trade off should work. Worst case I just redesign and reprint with a manual air restrictor built in (God I live 3D printing).

 

Perhaps with some help from the community we can even come up with a mechanically self regulation restrictor that is built in and possibly works based on vacume pressure?

 

Idk, the possibilities are endless.

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I have looked and K&N does have a replacement for $81. And need to be special ordered. It would be nice to have the ability to go to the local parts shop for such a simple part.

 

Given the air restriction requirement (does anyone know the exact mesurment for that?), I would think the extra air flow from a K&N might mess things up anyways??

 

I have 2 specter air filters I'm looking at now. One is slightly smaller in surface area so I think the trade off should work. Worst case I just redesign and reprint with a manual air restrictor built in (God I live 3D printing).

 

Perhaps with some help from the community we can even come up with a mechanically self regulation restrictor that is built in and possibly works based on vacume pressure?

 

Idk, the possibilities are endless.

 

While your at it make us some injector holders for our bikes and injector lines too... MAUHAHAHA

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In my experience with K&N filters on Yamaha motorcycles you can usually get away with a K&N if you have not made any exhaust modifications. Remember that part or the air flow restriction is in the design of the air filter box. If you have not removed/modified the box, it might lean things up a bit but not drastically. Now if you've modded the air box and/or gone to an after market exhaust and then go to a high flow air filter you will definitely need to re jet your carbs.

 

I ran a K&N air filter in the stock air box and Vance & Hines 4/1 header on my '81 Seca 750 with out re jetting by adding a couple layers of oiled shop vac filter paper to the filter. This restricted to flow enough to keep it from being way too lean. It also had the added side benefit of letting me just replace the filter paper rather than having to clean the pleated filter.

 

I have not tried a K&N filter in my Venture.

 

BTW, if anyone has gone to the pod filters, do you have tuning problems? On the inline engines(XJ) it's nearly impossible to get them to run well at all throttle positions due to turbulence at road speed. Even if you get the flow regulated at idle they stumble at WOT at speed or if you tune the flow to account for the turbulence they will not idle well and you have no power off idle.

 

I'd think that may not be as big a problem on the Gen 1 Venture if you keep all the plastics in place.

Edited by luvmy40
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In my experience with K&N filters on Yamaha motorcycles you can usually get away with a K&N if you have not made any exhaust modifications. Remember that part or the air flow restriction is in the design of the air filter box. If you have not removed/modified the box, it might lean things up a bit but not drastically. Now if you've modded the air box and/or gone to an after market exhaust and then go to a high flow air filter you will definitely need to re jet your carbs.

 

I ran a K&N air filter in the stock air box and Vance & Hines 4/1 header on my '81 Seca 750 with out re jetting by adding a couple layers of oiled shop vac filter paper to the filter. This restricted to flow enough to keep it from being way too lean. It also had the added side benefit of letting me just replace the filter paper rather than having to clean the pleated filter.

 

I have not tried a K&N filter in my Venture.

 

BTW, if anyone has gone to the pod filters, do you have tuning problems? On the inline engines(XJ) it's nearly impossible to get them to run well at all throttle positions due to turbulence at road speed. Even if you get the flow regulated at idle they stumble at WOT at speed or if you tune the flow to account for the turbulence they will not idle well and you have no power off idle.

 

I'd think that may not be as big a problem on the Gen 1 Venture if you keep all the plastics in place.

 

Inlines can be tuned to run properly with pods but isn't easy, it really requires a tunable exhaust system too. Also what most guys miss with pods is that the air flow into the carb mouth, depending on the carb, typically needs a few inches of straight flow for the circuits to meter properly. Pods create turbulent flow and the carbs simply won't work right. Ever. Velocity stacks with pods can work, but it takes effort. Another key is that with an air box where all carbs share an air chamber that is a factor in how they operate although I don't have the engineering chops to try to talk about how .

 

I have an 80 XS1100 with velocity stacks and pods, Supertrapp 4 into 1. 125 mains, 47.5 pilots, 190 pilot air jets, 6 discs in the muffler. It starts hot or cold on the first revolution, idles right, pulls strong all thru the tach with no stumble at mid range transition. It took a while and I know what I'm doing, if I were someone who didn't and had to ask for help in a forum at every step without the patience and an organizer full of Mikuni jets I can't imagine what a nightmare it would be to try to get it right. That's another thing, Mikuni flow rates their jets differently than others, if you pull a Mikuni jet and replace with aftermarket with same label it is most likely not the same diameter orifice and not the same flow rate.

 

Yamaha is so good at flow engineering that other manufacturers have contracted them to design their intake systems. Being a few hundred years short of their engineering experience I don't try to second guess them. It frankly isn't all that difficult to set an engine up for flat out acceleration, but starting cold, running smoothly at all rpms, transitioning smoothly and generally behaving in a civilized fashion is another thing entirely.

 

If stock filters are no longer available for a bike, my first approach is to search by filter dimension, there may be a filter that is much more common that is very near the same dimension and with a slight mod to the air box would work fine.

 

Tim

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Wow this thread really blew up! But I love it. It's great getting down into this technical stuff because I think it will allow the community to come up with solutions to parts that that are hard to find before they are impossible to find.

 

As a note to everyone, I am keeping the original air box. I am simply replacing the small plastic peice that the filter itself sits on. So from what everyone has said. I think it should work just fine. I got the prototype printed out last night and will mount it today along with posting pics. From there we can fine tune for airflow (if needed). Otherwise I'll just go straight to adjusting print setting to get a cleaner looking final product.

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While your at it make us some injector holders for our bikes and injector lines too... MAUHAHAHA

 

Injector lines on an 83'?

I may need more coffee in me to see those. At any rate, shoot me images and if you could use a caliper (avalible at harbor freight for $20) to give meaurments in mm, I'm sure I could make something up.

 

I print almost exclusively in PETG which dosnt melt till 400 degreed. And if that happens let's face it, you got bigger problems. Lol

Edited by Ipleedthe5th
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FIRST UPDATE:

 

OK, so I got the prototype adapter printed out and put in. Needed to do a little sanding on it because it looks like I was about 1mm off on the large curves.

 

Regarding air flow restriction, my super rough measurements on the factory filter came out to 54sq inches of surface area and the specter filter has roughly 45sq inches. So I think given the superior air flow of the specter, the two filters end up being equal (someone who is more patient and better at math than me please dig into these measurements so we can all be sure)!

 

Pardon the sloppy print, I did it quickly to make sure it works and fits and also had to manually drill the screw holes.

 

It mounted in great and WOW what a difference in performance. Bike no longer smells rich and the power is great. I already have the updated version printing out with the screw holes designed in this time and more top layers so it is more solid. Will update again once that's out. Otherwise the images are as follows.

 

(1st: Original air filter mount, 2nd: prototype mount, 3rd: mount with specter 8166 filter, 4th: prototype mount and filter in factory air box)

20180528_162543.jpg 20180528_162551.jpg 20180528_162609.jpg 20180528_162923.jpg

 

The air box cover also mounts on with no obstructions or need for modification.

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Nice! Very clean solution. That's pretty fast prototyping too!

 

Thanks man. Just the perk to having a 3D printer. I'm going to be making a lot more parts for this bike for sure. I know making some custom storage doors for compartments under the handlebars are on the list for sure.

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FIRST UPDATE:

 

OK, so I got the prototype adapter printed out and put in. Needed to do a little sanding on it because it looks like I was about 1mm off on the large curves.

 

Regarding air flow restriction, my super rough measurements on the factory filter came out to 54sq inches of surface area and the specter filter has roughly 45sq inches. So I think given the superior air flow of the specter, the two filters end up being equal (someone who is more patient and better at math than me please dig into these measurements so we can all be sure)!

 

Pardon the sloppy print, I did it quickly to make sure it works and fits and also had to manually drill the screw holes.

 

It mounted in great and WOW what a difference in performance. Bike no longer smells rich and the power is great. I already have the updated version printing out with the screw holes designed in this time and more top layers so it is more solid. Will update again once that's out. Otherwise the images are as follows.

 

(1st: Original air filter mount, 2nd: prototype mount, 3rd: mount with specter 8166 filter, 4th: prototype mount and filter in factory air box)

http://www.venturerider.org/forum/attachment.php?attachmentid=112760 http://www.venturerider.org/forum/attachment.php?attachmentid=112761 http://www.venturerider.org/forum/attachment.php?attachmentid=112762 http://www.venturerider.org/forum/attachment.php?attachmentid=112763

 

The air box cover also mounts on with no obstructions or need for modification.

 

Hey I am game if you want to send me info on how much you would sale a second prototype for. I am running alot of can we say experiments, I have a $50.00 stator in Tinker its from Race Electric on Ebay, Ebay is also where I got my emgo filter from. I also have Splitfire plugs in tinker too, very good product last alot longer then the NGK plugs I only switched the splitfires this winter because I dropped one so I just ordered a set of four. I have all LED lights in Tinker also, I will say better lighting from an aftermarket headlight, I have pictures of that somewhere, I replaced the original bulb and put it in the stock assembly and never felt the aim and lighting was as good as it could be. enough of my tinkering

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I've had a K&N Air filter on my 85 VR for the past 6 years without any issues. Works exactly like the OEM filter for me. Perfect fit seems to have the same air restriction as the original.

 

Item#: YA-1283

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  • 2 years later...

Hey all,

 

Its been a few years since I put this up, but after doing some overhaul work on my bike this weekend I decided to take a look at the adapter plate I made and am happy to report that it is still in just as good of shape as the day I put it in 2 years and over 5k miles ago! I've already cleaned the filter twice which has been great and keep my 83' purring like a kitten. If anyone is interested in getting there hands on one, shoot me a message :)

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  • 3 weeks later...

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