I have a 2000 Dyna. I rebuilt the engine and it's big and fast and awesome. Now that you know that I'll get to the point. I have a Mikuni HSR45 carb, got the full kit, intake manifold breather carb, the whole 9. So after one season of riding i pull the chrome air filter cover off to make an adjustment to the carb and see that the air filter is destroyed. not dirty, not in need of a cleaning. completely thrashed. Ripped to pieces (wish i had a pic to post)
It's a K&N filter that mounts directly onto the carb (duh where else would it mount) and then the chrome cover bolts to the filter. So the filter itself is kind of holding the wait of the chrome cover. This combined with the fact that my 98inch twin cam is shaking like an earth quake (sp?) at idle and even vibrates hard under throttle is wrecking the filter.
The wire mesh that goes over the red filter media is just cracked ripped torn and all kinds of f*****.
So since i'm running the mikuni HSR45 my air filter choices are limited to basically just buying another K&N that will get destroyed every season. and at 75 bucks a pop i'd like to not buy one every spring.
So what other set up can i run? obviously keeping the mikuni carb. would love a heavy breather style set up with the big cone filter but they dont make one that fits the mik.


Ideas?

btw this is what the filter alone looks like

 

So you think it is the vibration?
Are there bolt going from the front cover to the backing plate to hold it on?
Do they have spacers on them?

 

There is no bolt that goes from the chrome cover to anything other then screwing into the actual filter. I'm sure vibration is what's ripping it apart because at idle you can look down and see the filter flexing as it shakes and those areas correlate to where the damage is.


I just got a new k&n filter today and put it on minus chrome cover. So I'll be fine as long as no rain. This is temporary for now until I find a better AC set up

 

My old K&N filter that I had for my Mikuni HS40 had two bolts in it that I used to mount it to a bracket on the engine, so the entire unit was supported.

You see those two rubber nipples on the back of the filter in the link you posted....Well they are just covers for the bolts. You need to cut the rubber at the base near the main filter body and the rubber slides off. You then have two bolts that can be mounted to a bracket that mounts to the engine.

cheers

 

Yes the back of the filter has 2 studs which bolt to brackets that are bolted to the head as part of the breather system. So the Filter itself is held on the bike by a hose clamp that connects it to the actual carb, then the two studs and nuts holding it at the head. So the filter is held on securely.
The problem is there is a chrome cover that goes over the filter. This is held with one bolt that goes through the center of the chrome cover and is bolted into the filter. Same as the original oval shaped chrome piece that would be on a stock TC88.
The problem is that the round chrome cover has a fair amount of weight to it, and so that being only secured to the filter (idk how they would do it any other way) is hard on the filter. Now as the engine runs and vibrates it is shaking the filter which is holding this chrome thing on it also. the filter is not designed to be that structual so it just rips it apart. when i get home later tonight maybe i'll take some pics and add them to show what is happening a little better.

The root thing I'm asking is; what type of aftermarket air cleaner set up can i get that will go with my HSR45 carb? looking for something with the elbow and cone filter similar to Screamin Eagle heavy breather kit (only fits CV carbs)

 

Most odd....

I ran the same K&N filter for about 10 years with a chrome OEM cover fitted and never had an issue (albeit on a HS40).

If your engine is vibrating that much then your most likely going to have issues with whatever Air Filter you fit. Why not fix the root cause of the problem which seems to be excessive vibration. Your engine should not be vibrating so much as to destroy air filters.

 

The OEM cover that is oval shaped is not big enough to go over this filter.
My engine is vibrating just as much as any other bored out cammed up Twin cam it's just that the chrome cover is perhaps too heavy.

And again i'm asking more about what other AC set up can be run with a mikuni HSR carb. No options?

 

I feel your pain! I run the same carb/AC on a 121 and they have lasted longer than that but, I still go through the same thing. I am able to get several seasons (8-10k miles) before replacing. Was looking into a new set up and had no luck. Hope you get it worked out and that we can find an option.

 

Is your system running rich and coughing fuel back into the filter? My shovelhead was doing it and sparking the the inside of the filter. Because the oil is on the outside to catch fine particles the inside is dry. When it'd give a cough or 2 warming up the fuel weakened the filter causing it to shreds in places. After a lot of swearing and farting around with needle, jets and fine tuning the air/fuel I haven't had a problem. I'm guessing your bike sounds like an angry drag bike (which is great). Though it may need that very fine finishing tune of the HSR45. They are a bitch to get right but once you get it's sweet spot you'll know. Racing carby with multiple fine tuning possibilities = A headache until you're well versed in every part of it. Can be the difference between just a couple of mm leaner or richer. A rise or drop of the needle. A perfect jet combination. Because I have kickstart as well I knew it was close when it was getting easier to kickstart cold

 

You can use an adapter that lets you use air cleaners made for the stock CV carb. Then there are a lot of good choices like S&S, Ness, Screamin Eagle.

I use the adapter and a S&S teardrop with my HSR42 carb, works great.