$3 pod filters

[Old guy]

I bought a bike, the air box lid and filter didn't make the 33 year trip with the bike.

So, I've been struggling with the trying to work around the missing parts, solution 1 was getting me nowhere, the carbs have been on and off more times than I can count and more jetting changes than I can count.

Got tired of wrestling the carbs on and off to make changes that were getting me nowhere. Now they come off with the pods in place So I improvised again and it's way closer than it's been before as far as running right. I have a feeling stock jetting is probably going to be right with this setup, wouldn't that be a kick in the head.

The foam material was a filter element for a window AC unit. $2.59 at the hardware store.

I figure if the stock jetting works, this would be a super cheap and easy mod for people to do, especially if it works on the stock jetting. Even if it's not the stock jetting, once it get it dialed, I'll update the thread.

Pretty simple mod, really cheap. I used 2 layers of the foam and lightly oiled it.

As a bonus The bike also sounds really mean and more like a modern bike now.

 

[Gregory]

Subscribed

 

[leedutcher]

Looks great. Good luck with the tune

 

[Old guy]

I've been all over the place with the jetting trying to get this thing to even remotely come close to running right using a paper element and an improvised air box lid. Nothing made sense.

Jet it one way it would do one thing, jet it another it would do something else that made no sense.

Stock on this bike is a 42.5 pilot and a 110 main. Right now I'm running a 45 pilot and a 115 main, it's closer than it's ever been to running right,I just didn't want to swap jets again. Before oversized on the main and pilot it would hit a certain RPM and it was like a rev limiter. Big jets, 5 k, go smaller 7k, then went huge and it would go higher than 7k but not in a hurry, mid range was soggy and weak, just ****ty all around.

Left the jets that were in, in, and took it out and it's almost normal, just really sputtering after 8k, which I have a feeling is rich.

I'm going to go back to stock on the pilot and 112.5 on the mains because I started drilling the 110s stock jets larger and larger to try to figure it out. If it does good, which I suspect it will I'll go get some 110s. If it runs right on stock jets like this, WTF. this would be the easiest and cheapest mod ever for this bike, GS650. All of the advice I've been getting has been for 1000 and 1100 bikes, but who knows, it might work out well for other bikes.

 

[Crankthat]

Interesting!
I would be worried on the foam breaking apart.
How it holds up to the gas fumes.
Looking forward to learning on how this works out in the long term.

 

[Allie]

Glad it seems to be working for you! If this ends up to be your solution you can get a sheet of Uni foam that you won't have to worry about degrading or breaking apart. It's pretty cheep and has enough foam to make your pods probably x2 with some left over. I think I got mine at Dennis Kirk.

 

[Allie]

I didn't see any at Dennis Jerk, but Amazon has it. $13 for a sheet of green seems worth it to me.

 

[Old guy]

Or $0.97 at Home Depot

http://t.homedepot.com/p/Frost-King-15-in-x-24-in-x-1-4-in-Foam-Room-A-C-FPR-2-Air-Filter-F1524/202318549

 

[Griffin]

There's filter material, then there's filter material. The filtering requirements for an A/C unit are far different than the filtering requirements for an internal combustion engine. Using filtering material not designed to protect an engine is a really, really, bad idea, unless you enjoy rebuilding engines for a hobby.

Allie suggested using UNI filter foam for your project, which is specifically designed to protect an engine. Using A/C filter foam to save $15 could cost you several hundred dollars in engine damage in fairly short order.

Your engine, your decision.

 

[Griffyn]

There's filter material, then there's filter material. The filtering requirements for an A/C unit are far different than the filtering requirements for an internal combustion engine. Using filtering material not designed to protect an engine is a really, really, bad idea, unless you enjoy rebuilding engines for a hobby.

Allie suggested using UNI filter foam for your project, which is specifically designed to protect an engine. Using A/C filter foam to save $15 could cost you several hundred dollars in engine damage in fairly short order.

Your engine, your decision.

This. In large doses.

What you've got going on looks great, I love the way those pod boots flare out like that and how it looks on the bike. I'd definitely go with those if I was building new pods. But definitely invest in some UNI filter material, it is the right thing for the job and will safe you many hours and dollars later on.

 

[Allie]

Don't get me wrong, I LOVE cheap. I cut up a huge mouse pad to seal my air filter with. The Uni is fine foam, the air conditioner stuff is usually pretty coarse in my experience. Uni won't break down from gas fumes, air conditioner stuff... who knows? The air conditioner foam might work fine for experimenting, but it's risky in the long run. Uni = no risk for $10 more, that's very cheap insurance and much less than buying a set of pods.

YMMV, that's just my $3.95.

 

[Old guy]

I get it.

I actually went to the hardware store to get numbered drill bits to drill out some main jets. I had been looking for some foam sheet to wrap around my paper filter. One thing led to another and the plans changed, for the better, to where it's at now.

If I get it running right and change to a different foam and it needs jetting again, I'll go back to this foam.

It seems foam is rated in PPI (pores per inch). UNI offers foam in multiple ratings from coarse to fine. Conceivably I could use seat foam cushion as long as it's open cell.

 

[Griffin]

I get it.

I actually went to the hardware store to get numbered drill bits to drill out some main jets. I had been looking for some foam sheet to wrap around my paper filter. One thing led to another and the plans changed, for the better, to where it's at now.

If I get it running right and change to a different foam and it needs jetting again, I'll go back to this foam.

It seems foam is rated in PPI (pores per inch). UNI offers foam in multiple ratings from coarse to fine. Conceivably I could use seat foam cushion as long as it's open cell.

That is one measure of filtering material. Another one is the micron rating, which tells you the smallest particle size (measured in microns) that a filter element can remove with at least a 99.9% efficiency. In other words, if a filter has a 5 micron rating, it will block at least 99.9% of particles sized 5 microns or larger from passing through the element and continuing downstream.

A/C filters also do not have to be oil and gasoline resistant, an engine oil filter does. Many types of foams will rapidly degrade after exposure to petrochemicals, even if it is only the fumes. Foam elements designed to be around petrochemicals obviously will not degrade. They are actually designed to function utilizing petrochemicals (filter oil) as part of the filtering process.

 

[Old guy]

On 102.5 jets it runs w/o issue all the way to redline. These are restrictive, so peak power is about 6-7k and then it tapers off, no sputtering or cutting out, but not very fast.

Are these bikes just slow?

Back to the drawing board.

 

[tkent02]

Are these bikes just slow?

Only when the airflow is all boogered up.

7,000 RPM is supposed to be the start of the last big torque increase, you know, the big one that makes a GS worth owning.

A set of K&N pods and a jet kit is money well spent.

 

[Old guy]

There's an air box lid up the road.

I've got a lid made out of 1/4 ply, even still it runs like **** on stock jetting.

I'm going to go back to that set up with the leaner jetting, richer jetting was taking it in the wrong direction.

 

[tkent02]

Is this some kind of Suzuki?

A GS maybe? Big or small?

 

[Griffyn]

Is this some kind of Suzuki?

A GS maybe? Big or small?

Looks like a G of some size? ::shrug::

 

[Guest]

There is something to say for doing it right. I've stopped going for red line, it seems I'm at 10,500RPM before I know it. Besides shaking the cobs out every now and again, I don't want to damage it.

 

[Old guy]

1981 Gs650gl