[Guest]

Ok, I installed a set of Mad Duc Air filters in a friends 2000 996 about 2 weeks ago. He calls me and says that both filters popped off of the bell housings, and all that is left of one of them is the plastic housing (the element is missing!). The only ting we can think of is that the element went into the throttle body, but we can't see it or any remains of it. The bike didn't have a loss of power or poor throttle response (symptoms that I would expect in that situation). I can' imagine those things just "popping" off as they were a pain to get them all the way on (until the popping noise). He is also complaining of a slight, intermittent "knocking", sound coming from the "front of the bike". He says that it sounds like the engine, but it only does it about once every 5-7min. When I had the bike, I replaced the timing belts, changed the oil, and installed the filters (he was previously without any air filters). The bike ran like a scalded cat when I gave it back to him (it had no issues when he brought it in, just needed maintenance). My friend handed me the filters, so I didn't recomend that particular brand, only something that goes on the bell housing as opposed to the stock location.

Has anyone else had a problem with the Mad Duc Filters, or is this a first? He is bringing the bike back to me tomorrow, so what should I look for regarding the missing filter element?

Thanks in advance for your help.

 

[Guest]

Re: Help with Mad Duc Air filters (Reckless_Kelly)

Melted foam on the intake or exhaust valves, valve seats, trace the missing filter to the cylinder that lost the filter. If it runs fine you dodged a bullet. If it's popping and missing I'd check the plugs for being fouled by the foam. Check everything! The knocking isn't a good sign but doing it 5-7 minutes at a time sounds odd like something is floating around somewhere in the motor. More than likely the owner beat the crap out of his better running bike after you gave it back to him and something else might have failed. Considering he didn't have common sense to run the bike with filters, anything is possible. Mad Duc filters, cost-wise are a cheaper source for filters. I always stayed away from them for a number of performance reasons. Keep us informed.

 

[Guest]

Re: Help with Mad Duc Air filters (Hyperpasta)

Further to what Art said maybe a compression check would not go astray to measure any valve damage if any and for peace of mind.

 

[Guest]

Re: Help with Mad Duc Air filters (Hyperpasta)

It's not that it's knocking for 5-7 minutes at a time, it knocks once, then does it again in 5-7 minutes. I'm thinking that the filter got sucked in and is causing one cylinder to run a little funny every now and then. I still don't have the bike back here to look at it though, probably won't until tonight. It just concerns me that the filter housings BOTH popped off like that.

 

[Guest]

Re: Help with Mad Duc Air filters (Reckless_Kelly)

Are you sure the filter isn't melted onto something? Foam melts into almost nothing - look for a small blackish hard plasticy lump somewhere whether its inside the intake port or in the airbox area.

 

[Guest]

Re: Help with Mad Duc Air filters (Nick D.)

My 748 had those on it when I bought it and they were self destructing.The intake valves were coated in melted black plastic looking bits.They got the heave ho into the trash.