Changing a V-twin to a single carb?

[kevie]

I did this with an XV1100 10 years ago. There was a guy in Canada making a manifold and the most popular carb was a CV off a hardley. It worked well improved the torque low down, I think it was called KJS. Will find out for you.

Yep the site I found that are producing them is KJS probably same company, http://www.kjsmotorcycleworks.com/kjs_manifold.htm they seem to just bolt strait on the engine without rubber buffering of any kind and the carbs the only part with a rubber flange. they using the Mikuni TM going by the picture on their site same as the Harleys are running.

[kevie]

Well the mikunis et al are simple enough, but you will have some setting up for sure - and that probably means dyno time or at least a fuel-air ratio gauge on your bars while you tune it - still not cheap. Then there is the problem of finding a single mikuni that large. Why not put two of them on it? There's often carbs on trademe for late-ish model 600-1100cc bikes.

Steve


Steve

The TM Mikuni according to Anza in Palmy will run a Vtwin Ok, as they are what the Harleys are running as a single into twin cylinders. and the pics on http://www.kjsmotorcycleworks.com/kjs_manifold.htm show a single Mikuni carb with the conversion, in their pic it looks relatively simple setup, on one of the other pages it shows all the parts that become obsolete after converting the fuel intake lol

[doc]

Google the "Virago mailing list" and search for the KJS manifold

[SS90]

I am really interested to see that there seems to be no problem with having a solid mounted manifold like that....Harley pissed around with manifold mounting systems for years to get the expanding type design they ended up with.

I guess the Virago may well run substantually cooler than "american muscle", and, as such not expand as much.

I wouldn't have thought so, but there you are!

[kevie]

Google the "Virago mailing list" and search for the KJS manifold

Came across the KJS advert on their website after I started the thread .... they dont have a flexable manifold and a single 40mm Mikuni Carb ... the pic you posted looks good eh .....

[kevie]

I am really interested to see that there seems to be no problem with having a solid mounted manifold like that....Harley pissed around with manifold mounting systems for years to get the expanding type design they ended up with.

I guess the Virago may well run substantually cooler than "american muscle", and, as such not expand as much.

I wouldn't have thought so, but there you are!

Yeh I would have thought there would be problems with joining a V-twin with a 'non-flexable' manifold which is why I started the post, but as mentioned I found the advert by KJS and going by that they seem to suggest a fixed manifold is not a problem.
My original thought was to run the 40mm manilold into the existing rubber manifold flanges to give it flexability ..... (still think that is the better idea), altho will the weight of the manifold and a Mikuni Carb be ok in flexi joints weightwise ..... guess only one way to find out LMAO just looking for a Mikuni (36mm or 40mm) for around $200 or so but also found the KEIHIN FCR which I understand is OK too and found a site that advertised KUSO carbs (never heard of them) that look similar altho they seem to have 32mm as largest and dont think that would be big enough.

[Motu]

At the last Claudlands swap meet there was a brand new Blue Magnum 38mm,still in the box @ $50.That would be perfect,best bolt on and run carb I've ever used....and easy to tune too.

[Subike]

what about a twin choke side draught?
A delorto or a webber, heaps of jets availabile for tuneing
heaps of different styles of air filters, ram tubes etc
are already used on HD's with success
easy as to make a manifold for and not a complex carb either.
just a thought

[doc]

I am really interested to see that there seems to be no problem with having a solid mounted manifold like that....Harley pissed around with manifold mounting systems for years to get the expanding type design they ended up with.

Aint no expanding type manifold on my sporty and its never been any problem.

[kevie]

At the last Claudlands swap meet there was a brand new Blue Magnum 38mm,still in the box @ $50.That would be perfect,best bolt on and run carb I've ever used....and easy to tune too.

came across a website last night with all the different swopmeets .... saw the Hammie one and they had one not far out of Wanganui too ....... bugger eh seeing them too late to attend lol

[kevie]

what about a twin choke side draught?
A delorto or a webber, heaps of jets availabile for tuneing
heaps of different styles of air filters, ram tubes etc
are already used on HD's with success
easy as to make a manifold for and not a complex carb either.
just a thought

yeh the mechanic I use said to think about that too.... he recons my bike will go like snot LMAO havent told him im a nana rider LMAO

[porky]

Got an electronic copy of the 98 sportster workshop manual. Has some good pics and exploded drawings of carb (keihan cv) and manifold. More than happy to flick you a copy if it helps??

[rogson]

I presume you are looking to install the carb between the cylinders? If so, I have a down-draft 36mm Mikuni CV carb (BDS36SS) from a Suzuki VX800/VS800. It is designed to mount between the cylinders where space is limited - so is quite compact.
PM me if you are interested in it.

[kevie]

Got an electronic copy of the 98 sportster workshop manual. Has some good pics and exploded drawings of carb (keihan cv) and manifold. More than happy to flick you a copy if it helps??

Thanks for the offer, my mates a motorcycle mechanic and I went over and had a look at a couple of Harleys in his workshop with the setup im thinking of and chatted to him, so have a good idea now what to do, the manifild will have to fit into the rubber flanges I have to allow for movement and I recon also make it easier lining them all up as they will give me a mil or 2 give and take on the measurements...... so ..... first off im just chasing a person who is selling a Mikuni TM 38mm carb at the moment mechanic said minimum of 36mm and max of 40mm carb will do fine and he will sort the jetting out for me , he also recomended I avoid the CV carb as what I plan will be easier with the TM sort of gobblygook to me LMAO dont know too much about the differences as I have only compared them off pics on the net.

[kevie]

LMAO sheesh ..... talk to experts and they all have differing opinions LOL told NOT TO use the CV carb but use the flatside by a friend that builds custom Harleys and repairs bikes, and talked to a couple Harley shops and they said not to bother with the flatside carb as the CV is a far better carb , but both Harley dealers had the same reasoning for that (they did agree on something ) that the CV is self compensating and adjusting and handles the fuel needs better than the flatsides and both of them cant understand why so many Harley owners rip out the CV and go for the flatside....... *****wonders whose right**** .... but have just bought a second hand CV carb off a 1200 sportster and will see if it all works out,,,,, then have the manifold to build and the task of rejetting the carb to suit the bike. will let you know later if I got things right of stuffed it all up