SU Carb as an alternative to the Mikuni, now on hold,carb ok

[t140v]

Evening All, as I was having a few problems getting my bike running after I had removed my carb to clean the air inlet filter and sort out a float bowl leak I decided to bite the bullet and go for a SU carb conversion and see what the performance is like, I have had my bike nearly 3 years and covered 5000 miles so know it intimately.
I was suprised to find that there was no accelerator pump spring fitted and the float bowl gasket was made of composite when I stripped the carb to check the jets etc, moving on I made a new gasket and tried the bike what a dog, flat spots serious hesitation etc etc, you are having an SU.

Jumped on ebay and bought a pair of 1.5" HIF4 carbs with manifold, tried to buy an ADR needle (Norton's SU needle) but no longer in stock so bought the nearest size ( but a little richer not leaner) got some 12mm Ally plate, if you think this is easy stuff to work with think again, a couple of days work to get the conversion piece the right shape.

Have 2 carbs a left and right so when I get the left hand one sorted will get the right hand converted as well.

Then I was sent a new old stock float bowl (rubber)gasket from a forum member, problem solved, no flat spot, no hesitation, pulls like a train, never run like this since I have had the bike, no problen setting the cables what a machine.

But I have not lost the momentum and still working on the SU conversion, I now have the experience of the bilke running in different stages of tune, crap, better, and wow !

Regards Stuart.

[pmcburney]

Stuart,


Not sure how to read your post...

Have you had success with the SU carb, or the original carb?

Was the rubber float bowl gasket for the SU or the original carb?


Ta
Paul

[t140v]

Evening All, & Paul, the sucess was with the Mikuni Carb but I am still going for the conversion to see if there is any improvement, the conversion manifold is made waiting for an opportunity to try the two together weather nice here did another 100mile on the bike today.

Regards Stuart.

photos to come next week

[t140v]

Had a couple of minutes to spare so removed the carb to see how the adaptor plate fits the manifold and where I need to trim excess aluminium from the outside and port profiles, not bad for a first fitting but a long way to go yet, need to make a support for the throttle cable where to put the fuel line and the line from the oil pump swap the needles air filter etc etc.

Attachments:

[t140v]

First attempt not bad, need to make another manifild so I can connect to the original Suzuku intake horn and air cleaner. looking at other mods as well.

[snowrench]

I had the misfortune to have been a Harley mechanic in a dealership for quite a few years, and one of the routine conversions I performed in an attempt to accelerate the bloated bellied riders and their leaden bikes was to remove the stock CV Keihin carbs and install Mikuni 40 or 42 flatslides, and occasionally, under protest, S&S Super E's. As a result, I have quite a few of those stock CV's laying around, and I happen to think they are a great Carb. If my my A wasn't running so well I would be very tempted to graft one of those on, and certainly before I would tackle an SU, although I do think they are a fair carb. If you know any HD guys in your area, you might find the Keihin CV's can be had in new condition for a few bucks. Intriguing....

[ap951]

why anyone would remove the stock constant velocity Keihin form a Evo Harley & replace it with an S&S Super E has always been a great mystery to me. When properly tuned they run beautifully with the stock CV Keihin.

I did pull the plug that exposes the idle mixture screw so I could adjust it.