I’m using a 2001 Nevada Club 750 as the basis of a cafe racer project and I want to fit K & N filters straight on to the carbs. The standard set up has the carbs linked to the central air box and pipes running from each cylinder head to a smaller airbox which piggy-backs the main air box.
My question is; when I do away with the main airbox, do I need to connect the pipes from the cylinder heads to anything?
The pipes from the rockers are part of the breather system, so shouldn’t really be blocked up or just vented to atmosphere, as you may risk condensation from short runs/cold days. I guess it depends what alterations (if any) you’re making to the standard breather set-up, you may be able to vent the rockers into the system elsewhere.
Does the Nevada have a oil return pipe to the sump like the V50? I have a V50 with KN’s on. I fitted a Land Rover TDI oil air separator. 10 quid eBay. Two pipes from rockers go to top of this and the sump return connects to the bottom. It works on the most efficient way of separating the air oil using a cyclonic effect a bit like a dyson. It is not large and fits neatly between and slightly forward of the KN,s. If your bike does not have the sump return. You need to make the pipes longer and feed them down towards the bottom of the bike. You will not get emulsion problems if the bike is ridden properly-no short journeys. You might want to consider jetting up your main jet and doing a plug test depending on how serious you are about it performing well. Most people don’t bother. There are some great cafe racers based on the small blocks and even the big ones as well. The neat ones is where the battery is put under the bike giving that space frame look.
not worth spending much on the breather, the small blocks don’t need much effort or money to sort.
Remove the sump return and block the hole with a bolt and crush washer, connect the rocker boxes to a ‘Y’ type 8mm compressor barb and then get 1 to 1.5 meters of 8mm fuel hose , connect to the 3rd port on the Y barb and then carefully run to the rear of the bike .
You will be amazed how much milky mucky water ends up coming out the breather and not pushed back in to the sump…
inlets wont get clogged up with oil vapor etc.
you must loop the rocker box hoses down a few inches then up high under the tank to let the oil vapor condense and go back to the rockers.
Done this ( as per guzzoligy) on my last 5 small blocks ( including my 2 V7 Stone powered V65TT’s)