3C Carb to airbox rubber boot too short on right side only - seeking info/solution

You need a minimum amount of oil in the filters; no oil reduces their dust-catching, and too much strangles performance. The problem is that those DNA ones is there preety stiff and dont allow squeezing, so you need to mop them with paper towels a lot to take up as much oil as you can. We occasionally used to end up on dirt roads a few times up to 100ks or so, not ideal for engine life.
 
Vince said:
I am running pods, the ones Red recommends. I was very keen to run an Airbox, but apparently they dont fit. Some measuring had me thinking you need to cut the box down to the point where there isn't much left. I have no complaints about how the bike runs, never got to the point of a Dino test and always regretted that. Maybe one day to confirm jetting as I have a very non-typical engine and exhaust. I have only ever cleaned and re-oiled the air filters once since fitting; there was minimal dirt that came out. The cleaning and oiling kits are pretty expensive, but water-soluble filter oil is important to actually get proper dust stopping.
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My bike came with K&N pods, which nicked the airbox side covers paint slightly. The box has the bottom brackets that sit on the frame mounts, but don't bolt on. The top has a little hook on top, I've pulled it snug with a zip tie for the time being, seems fine. The two foam frame cushions are in good shape, and the box fits very well. I made a breather hose using 3/4" heater hose by heating it in a toaster oven at 300F with internal and external shaped supports (tubing bender coil thingo inside, bent alu bar stock and hose clamps outside) to curve it into the proper shape, and used a nylon elbow that fit nicely into the upper inlet. Does the job.
 
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gpzkat said:
My bike came with K&N pods, which nicked the airbox paint slightly. The box has the bottom brackets that sit on the frame mounts, but don't bolt on. The top has a little hook on top, I've pulled it snug with a zip tie for the time being, seems fine. The two foam frame cushions are in good shape, and the box fits very well. I made a breather hose using 3/4" heater hose by heating it in a toaster oven at 300F with internal and external shaped supports (tubing bender coil thingo inside, bent alu bar stock and hose clamps outside) to curve it into the proper shape, and used a nylon elbow that fit nicely into the upper inlet. Does the job.
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The airbox isn't painted.
Paul
 
Dellortoman said:
Are you using the airbox or pod filters, Vince?
I'm using pods with my Mikunis. I never tried connecting them up to the airbox because my old rubbers were fucked and I didn't think it was worth buying new ones because they probably wouldn't have fitted the Mikunis anyway.
The pods seem to work OK in that the bike runs well, but I dunno how good they are at filtering out dust. They also rub on the plastic side covers, which wears holes in them, so I've had to replace them once already and I'd prefer that it not become a regular maintenance item.
I've come to the conclusion that the pods may not be an ideal solution, but I'm not sure the airbox would be any better.
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Cam,

I simply reduced the depth of the airbox to allow easy fitment of the rubbers to the Mikunis, about 10mm iIrc. Intake stubs supplied by Topham.de... I was quite happy about how easy it turned out. They are a tight fit, but nothing a dip in hot water won't cure.

No filter in the box. It's fitted mainly to significantly decrease intake roar and to prevent the rearward bit of the bike getting grubby from fuel blow-back. Reckon I'd fit some sort of filtration if I ever contemplate crossing the Nullabor or trundling up the Birdsville Track though. None of that type of landscape in my neck of the woods.

piet

DSCN8319.JPGDSCN8322.JPG
 
sfcpiet said:
Cam,

I simply reduced the depth of the airbox to allow easy fitment of the rubbers to the Mikunis, about 10mm iIrc. Intake stubs supplied by Topham.de... I was quite happy about how easy it turned out. They are a tight fit, but nothing a dip in hot water won't cure.

No filter in the box. It's fitted mainly to significantly decrease intake roar and to prevent the rearward bit of the bike getting grubby from fuel blow-back. Reckon I'd fit some sort of filtration if I ever contemplate crossing the Nullabor or trundling up the Birdsville Track though. None of that type of landscape in my neck of the woods.

piet

View attachment 103405View attachment 103406
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Clever and yet sympathetic mod.
 
sfcpiet said:
Cam,

I simply reduced the depth of the airbox to allow easy fitment of the rubbers to the Mikunis, about 10mm iIrc. ... <snip>
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Hi Piet
You appear to have straight inlet stubs on your bike. I'm using Red's angled stubs, so my carbs sit lower and more horizontal. But I'll see if I have an airbox somewhere that I can muck about with and trial fit. It may have to sit lower down than its original position. If I can get it to fit in a position where it looks like the rubbers might have a chance of bridging the gap, I'll order a set.
Cam
 
My carb position is pretty odd, Doug Home molded my 3c to change its angle and position and ported the hell out of it to change the gass flow a lot plus I use rubber mounts for 40mm carbs that are a different length. My carbs stick out further so the airborne if it fitted would be much thiner.
 
Dellortoman said:
Hi Piet
You appear to have straight inlet stubs on your bike. I'm using Red's angled stubs, so my carbs sit lower and more horizontal. But I'll see if I have an airbox somewhere that I can muck about with and trial fit. It may have to sit lower down than its original position. If I can get it to fit in a position where it looks like the rubbers might have a chance of bridging the gap, I'll order a set.
Cam
Click to expand...
Yes, using straight inlet stubs as supplied by Tophams, the Keihin/Mikuni concessionaire for Germany. I have no clearance issues whatsoever with either the stock "Jota" Laverda stubs nor with the Tophams items, but these offer a little more space behind the carbs by being a tad shorter than the originals, hence allowing easier fitment of the intake rubbers.

I have since abandoned the stock intake bellows in favour of tubes from a Guzzi Lemon Mk?. These have been fitted with 3D-printed adapters at the carb mouth and air box inlet. I don't have any proof of improvement but my gut feeling says anything smooth just has to be better than those rough original bellows. A sort of curved intake trumpet if you like.

piet
IMG_1574.JPGIMG_1573.JPG

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While my Sudco intakes on the FCRs for the SFQ look the goods, I was more than happy to sacrfiice 3rwhp to fit flex and large DNA filters under the seat. I can't really feel an y difference in performance and live happy in the knowledge that I have filtered air going into those rather expensive holes called cylinders. :cool: Besides, I get a nice midrange boost from the long inlet manifolds anyway.

FCR Flex intakes side.jpg
 
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