I've bought my RD03 about one year ago. I've got it ready for the 2016 and this year I've ridden more than 26000 km on it, one third on unpaved roads and muletracks in Italy, Balkans, Turkey and Georgia.
What really disappointed me about the bike is the air intake system, in a shitty place where a lot of dust enters (even mud can enter as I have experienced at the Cow Adventure!).
So I was looking for a solution, I've tried a filter skin, it was not bad but in Turkey I rode up to 3000 masl and I was costantly at 2000 masl and the engine was running to rich, so I had to remove it and the filter was filled quickly.
I've seen pictures of snorkel that was used on the RD04 marathon and I got interested on it.
This bike redirected me to Boano:
HONDA XRV 750 Africa Twin - 1992 DA COLLEZIONE Moto e Scooter usato - In vendita Monza e della Brianza
I've asked him and he can do it but in order to do it, a lot of things must be changed, as the bigger tank and the longer airfilter (I don't want to have the bigger tank and the longer airfilter, because it would be impossible to find a spare airfilter in case mine brokes). Moreover the price of this is more than 2000 €. No way.
From this website I got some informations and the owner even sent me some detailed pictures of a german guy that builded one alone:
AFRICA TWIN MARATHON - HOME
I've opened a topic on the italian Africa Twin Club and people helped me a lot on finding more informations:
Modifica Airbox Rd03/04 - Modifiche / Accessori - Moto Club Africa Twin Italia
One of them has even explained with a high precision technical draw how the airbox is modified:
View attachment 106521
Then another one redirected me to the german ebay were an air intake was being sold:
HONDA XRV 750 Africa Twin "Rallye Luftfilteranlage mit Sitzbank" RD04, HRC. | eBay
Africanqueens has something on their shop, I've asked them twice what was it about but I've never got an answer.
So I decided to build an air intake on my own, using fiberglass (I can't work and weld alluminium).
I've did some fluid dynamic rough calculations in order to compare the resistance of the original snorkel and the one I was building in order to have an idea about the cross section (Mine has a height around 20 mm, the original one was higher)
I've bought a used airbox from ebay and as soon I've got it, I've started the work. I've done the fiberglass directly on the tank, putting Cellophane in between (nothing sticks to cellophane, but be aware that there can be diffusion and some resin can pass through).
To form the channel I've used a foam covered with cellophane:
View attachment 106529
I still have to finish it by putting a round border at the entrance, some L profiles + a foam in order to make the seal on the airbox and a rubber tap for the tank screw hole.
The seat has to be modified aswell.
Right now with K&N airfilter and arrow PD the bike runs fine, the minimum is not affected by the new air intake, when the needle works, the bikes runs lean (the higher rpm the leaner it is) and I was surprised because the max jet is working fine and the bike runs up to the limit rpm. The noise of the airintake is very loud and gives the bike 10 "psychological" HP more.
Next step will be to implement a low density filter foam on the air intake, in order to find the best compromise (Then maybe I'll have to use a smaller max jet).
What really disappointed me about the bike is the air intake system, in a shitty place where a lot of dust enters (even mud can enter as I have experienced at the Cow Adventure!).
So I was looking for a solution, I've tried a filter skin, it was not bad but in Turkey I rode up to 3000 masl and I was costantly at 2000 masl and the engine was running to rich, so I had to remove it and the filter was filled quickly.
I've seen pictures of snorkel that was used on the RD04 marathon and I got interested on it.
This bike redirected me to Boano:
HONDA XRV 750 Africa Twin - 1992 DA COLLEZIONE Moto e Scooter usato - In vendita Monza e della Brianza
I've asked him and he can do it but in order to do it, a lot of things must be changed, as the bigger tank and the longer airfilter (I don't want to have the bigger tank and the longer airfilter, because it would be impossible to find a spare airfilter in case mine brokes). Moreover the price of this is more than 2000 €. No way.
From this website I got some informations and the owner even sent me some detailed pictures of a german guy that builded one alone:
AFRICA TWIN MARATHON - HOME
I've opened a topic on the italian Africa Twin Club and people helped me a lot on finding more informations:
Modifica Airbox Rd03/04 - Modifiche / Accessori - Moto Club Africa Twin Italia
One of them has even explained with a high precision technical draw how the airbox is modified:
View attachment 106521
Then another one redirected me to the german ebay were an air intake was being sold:
HONDA XRV 750 Africa Twin "Rallye Luftfilteranlage mit Sitzbank" RD04, HRC. | eBay
Africanqueens has something on their shop, I've asked them twice what was it about but I've never got an answer.
So I decided to build an air intake on my own, using fiberglass (I can't work and weld alluminium).
I've did some fluid dynamic rough calculations in order to compare the resistance of the original snorkel and the one I was building in order to have an idea about the cross section (Mine has a height around 20 mm, the original one was higher)
I've bought a used airbox from ebay and as soon I've got it, I've started the work. I've done the fiberglass directly on the tank, putting Cellophane in between (nothing sticks to cellophane, but be aware that there can be diffusion and some resin can pass through).
To form the channel I've used a foam covered with cellophane:
View attachment 106529
I still have to finish it by putting a round border at the entrance, some L profiles + a foam in order to make the seal on the airbox and a rubber tap for the tank screw hole.
The seat has to be modified aswell.
Right now with K&N airfilter and arrow PD the bike runs fine, the minimum is not affected by the new air intake, when the needle works, the bikes runs lean (the higher rpm the leaner it is) and I was surprised because the max jet is working fine and the bike runs up to the limit rpm. The noise of the airintake is very loud and gives the bike 10 "psychological" HP more.
Next step will be to implement a low density filter foam on the air intake, in order to find the best compromise (Then maybe I'll have to use a smaller max jet).