roundslide

[yamahansolo]

hey i was looking on old bike barn again and i had thought the carbs for the xj1100 were flatsides but they are actually roundslides and they are 700 bucks for a brandnew set. these are 33 mm and sound like they would be pretty good.
has anyone got any thoughts on these?

[mro]

has anyone got any thoughts on these?

700 bucks ???
Think I could add 3 or 4 more XSes if I could find the room to keep em.
Don't know why some seem to have a problem with the BS34 two's and three's


mro

[andreashweiss]

I have two complete sets of used xs1100 carbs if you want to consider used. 78/79 series bs-34 mikuni and 80/81 mikuni bs-34 either set $100 includes shipping. Both came off running bikes within last 6 mthes. andreas

[mro]

Just reread my post
May have sounded a little...
Nothing wrong with using other carbs on the 11's
Have read a few posts where changing to newer style carbs have givien the bike better performance, and have read others that have challenged the claims. So far no one has ever posted a dyno result to back up there claim.

One area not touched on about switching to a newer style carb has been if fuel atomization and air flow (not air flow volume) is significantly more efficiant than the BS carbs.


mro

[AlanB]

Hi MRO,

I am one of those with modern carbs on my bike; I also have dyno charts, but they have been pinned up on the wall of the shop for years, and are too yellowed and faded to scan decently.

The shop who did the work has closed, so I am trying to get in contact with the ex-owner to see if he still has the computer records, but I am not optimistic.

I could ink over the faded lines and scan 'em, but I can't imagine anyone will take that as "proof", so I will carry on trying to get better copies.

My bike dynoed up at around 70 bhp when stock, (very similar to another XS done on the same rig around the same time!) and gave a best of 95 with the Slingshots. We eventually settled around 90bhp, but with much better midrange and cleaner "cruising" (steady throttle!) settings.

I'll post the runs if I can get clean copies.

AlanB

[GNEPIG]

Allen B, you could try taking a picture of the prints and try to post them as photos (just a thought, not knowing the condition myself).

I have a set of 34mm Kehin CR round slides sitting on the shelf, maybe I'll have an extra "round- to- it" in the next week or two, put them on somethin and throw it on the dyno.

[pggg]

Good one GNE, I can tell the textbook experts right now the CR carbs give a big kick of power, although I doubt a dyno sheet could even show it, I had the similar carbs on my GS1000S, mikuni smoothbore 33mm, also some keihin flatslides on my hotted and lightened CB750K, ran them on a CB900 too, they'll bog down /splutter if you crank the throttle at low revs, just throttle control, smooth return cables help, they're not as bad as everyone makes out, in the power band they can't be beat, 5th gear accelerates like 4th gear, late model CV carbs give the best of both, easy to get at 150 bucks second hand, but still for 700 bucks you're getting brand new carbs, I wouldn't say no

[mro]

CR carbs give a big kick of power, although I doubt a dyno sheet could even show it,

I've not nay sayed either side about the newer carbs "debate" BUT if a dyno can't measure a noticeable power increase....

think that might change


mro