How to make pod filters work

[MarkCR750]

I read that the reason pod filters give issues is that the don't smooth the air before it enters the carb so decided to fit velocity stacks inside mine, then I realised I already had a set in the stock airbox, so ref photos below I pulled some chinese pods apart, enlarged the hole in the plate to accept the rubber velocity stack from the stock airbox, glued the stacks into the plates using "sikaflex" the best adhesive know to man, strong as hell and remains flexible when cured, glued the filter back on to the plate then just clamped the whole assembly onto the bike as you would with the original airbox, the difference is marked, I thought it was running well before but now it's much smoother , has more power, picks up even better and has a dead smooth tickover , best couple of hours I've spent so far regarding modding the bike, the filters were about £20 for the set of 4, the velocity stacks came with the donor bike, so if you've got pod issues do as below, cheers Mark

[florence]

very nice

[JamesH]

Good work there Mark. Simple fix and great idea..

[MarkCR750]

Cheers James, yes it's sometimes the simplest or most obvious things that work best, I'm going to get it on the dyno soon to check the fuelling, not really bothered what power it's making, it's more than fast enough but I don't want it to be running lean, the plug colours look ok but the piston crowns look a bit odd, mainly dark but with small patches of light tan so I'll be happier once it's checked out properly.

[Greebo]

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  These are K&N pods on mine which are slightly larger

[MarkCR750]

I would think you would benefit from a similar set up to the one I have now Greebo, looking at the photos of your filters there is an abrupt step from the filter to the carb, and also no distance between the two for the air to "straighten out", I am in Derby so if you want to take a ride over we could fit my filters to your bike and see what happens, I'm on the dyno Saturday but we can arrange it after that if you want to, cheers Mark.

[matthewmosse]

Thans for that tip, might help resolve some of my bmw r90/6 issues when I get onto that later in the summer, I just need to get some velocity stacks to mach the massive carbs.... may also get applied to a cb550 special or custom in the future. Have you checked the silkaflex is ok around fuel?

[Greebo]

I would think you would benefit from a similar set up to the one I have now Greebo, looking at the photos of your filters there is an abrupt step from the filter to the carb, and also no distance between the two for the air to "straighten out", I am in Derby so if you want to take a ride over we could fit my filters to your bike and see what happens, I'm on the dyno Saturday but we can arrange it after that if you want to, cheers Mark.

Hi Mark
I see what you mean, I thought it maybe possible to Dremal that step off ? if you look at my set up there is not enough room on my bike to have extended VS.
Thanks for the offer, but at the moment I am laid up & bandaged up, just had carpel tunnel surgery on my right hand, so wont be riding for a few weeks.

What about a meet sometime at CMC clay cross.
Theres the "custom & modified" Sunday on the 24th July, & then on the 7th August there is the "Classic Japanese Sunday"..i will be entering my bike in that show...weather permitting of course.

I hope all goes well with the dyno..

Thanks again
Cheers
Greebo

[MarkCR750]

Yes I don't think they'd fit, I'm pretty sure mine come half way across the upright frame tube so the panel on yours would be in the way, I've got them off at the moment and the carbs just checking that the intake boots are sealing correctly prior to the dyno, need some new ones really the rubber is hard and I have to heat them to get any give, yes I'm going to both of those shows and the 2 stroke day on the hustler so we'll meet up, might be worth taking the corner off you rubbers provided it doesn't weaken them , should be OK.

[MarkCR750]

Thans for that tip, might help resolve some of my bmw r90/6 issues when I get onto that later in the summer, I just need to get some velocity stacks to mach the massive carbs.... may also get applied to a cb550 special or custom in the future. Have you checked the silkaflex is ok around fuel?

Sikaflex isn't designed to be totally fuel resistant but there shouldn't be much fuel getting back there, maybe a bit of blowback but I doubt it will affect it, if it causes a problem I'll go over it with some fuel resistant sealant.

[royhall]

Did I read that right in one of your posts, you've got a good tickover with PD carb's. You must share your secret, is it prayer, alchemy, exorcism? These things were difficult when they were new. Respect indeed.

[MarkCR750]

Ha, sounds as though I've achieved a miracle then Roy!, yes it ticks over well although perhaps I've got it set a little high at around 1300 revs, I don't know what they should tickover at as standard?

[philward]

Great tip Mark - thats the beauty of sharing tips on the forum - without the medium of the forum, everybody would be getting frustrated all trying to achieve the same result! Some way off that with CR but will be using your tip
Phil 

[MarkCR750]

Yes I've picked up loads of good info over the last couple of years on this forum, right , carb balancing time, now which carb is it we use as the master?? 😀

[royhall]

With PD's that would be No.2 (the only one without any adjustment mechanism).