Attila!

[MAXIMAN]

Sensei has just finished rebuild the monster HUN!

He installed an 1179 big bore with his Nigel Patrick trick head and some special grind cams he designed. Of course Chinese water torture could NOT make him divulge the specs of his cams but apparently Atilla has a nasty habit chasing down V-Rods ...grabbing them by the neck and shaking them violently...seriously!

Dan tells me it pulls like crazy from right off idle to about 5000 rpm. But at 5-6 grand it goes ape. Apparently it is analogous to being shot out of the proverbial cannon.











Maybe if we ask real nicely we can get him to ride Attila to an XS rally soon.

PS: Check out the chromed kick stand!!!

[Dan Hodges]

Re: Attila!

I would like to convey my most humble thanks to my main man Maximan for posting these pictures for me.My photobucket still seems to have a gigantic leak.

Originally posted by MAXIMAN
Sensei has just finished rebuild the monster HUN!

He installed an 1179 big bore with his Nigel Patrick trick head and some special grind cams he designed. Of course Chinese water torture could NOT make him divulge the specs of his cams but apparently Atilla has a nasty habit chasing down V-Rods ...grabbing them by the neck and shaking them violently...seriously!

Dan tells me it pulls like crazy from right off idle to about 5000 rpm. But at 5-6 grand it goes ape. Apparently it is analogous to being shot out of the proverbial cannon.











Maybe if we ask real nicely we can get him to ride Attila to an XS rally soon.

PS: Check out the chromed kick stand!!!

[GNEPIG]

Nice bike Dan, have you found yourself a good Dyno man localy yet? Would be neat to see a pass with it. Would interesting to see how it compairs to Maximans numbers.

[Dan Hodges]

Dynoed

Originally posted by GNEPIG
Nice bike Dan, have you found yourself a good Dyno man localy yet? Would be neat to see a pass with it. Would interesting to see how it compairs to Maximans numbers.

Yes there is a good dyno facility here in my neighborhood that specializes in metric bikes and it would be an interesting camparison. I only have about 700 miles on it and once I have accumulated a thousand or so I will be putting it on the drum. Actually though an engine is the sum total of it's parts and based on that I have a good idea already of what's going on.Actually though I don't race dyno's or do the twisties but have several old friends who have mid 80's muscle bikes and we are constantly flogging these things on the Interstate for bragging rights.This is actually the second time I have gone through this thing and this particular go around I simply did some stuff that I have picked up on since I did the first up grade.

[motoman]

Super nice scoot!..................and apparently runs as well as it looks..............noticed the stock airbox........Hmmmmmmm, maybe some will get that the Yammy engineers had it all figured well so the carb diaphrams worked properly according to vacuum drop, velocity effect on intake boot, etc...........just my two cents.

[gmlever]

Very nice Bike ! What brand is the header ? And the windshield ?
Again very nice ! I'm looking for both for mine.

Thanks
gmlever

[Dan Hodges]

Attila's mods (some)

Originally posted by gmlever
Very nice Bike ! What brand is the header ? And the windshield ?
Again very nice ! I'm looking for both for mine.

Thanks
gmlever

The windshield is by National Cycle and is called,Street Shield.I have another National Cycle windshield called the Plexi Star II which is quite a bit larger but I like the street shield better as the bike is noticeably faster on the top end and gets a lot better mileage.The exhaust is by Super Trapp and this particular pipe was made for the XS in the eighties and could be purchased up untill about 1992 or so.I bought this pipe in 1987 but it got little use untill March of 06 as it hang in my garage for over 15 years.I also have a spare muffler setup that is also like new that I have removed the baffling from and I have two different cores,one 2 inch and one 2.5 inch.The air box is stock save for the base plate which has been drilled.For reasons too numerous to mention,I elected to stay away from pod filters even though I used K&N pod filters years ago on my FJ 1100.You can check out the windshield on National Cycles web site,but finding an original Super/Trapp header will be more diffulcult but they are out there if you really want one.Good hunting.Dan

[pggg]

That hotted motor would hum with these ZRX11-1200 C V carbs, 36mm, nice and civil for street/road bikes, while super-smooth fuel delivery from idle onwards, extra responsiveness and extra sheer power is pretty impressive, checking out inside, the modern CV carb, so slick and streamlined. Bandit 1200 carbs look similar too. Top carb is a 78' XS

[John]

Are the carbs in the pics upside down because you are 'Down Under', or have you discovered a new way of wrangling more power from the bike by inverting the carbs? How do you set the float levels on these carbs and keep them from flooding?

[pggg]

Tex, a good moderator/editor would be able to flip those pics 180 deg

[Ken Talbot]

Was there a poblem with an upside-down pic?

[cajun31]

Great looking bike

Dan,

Kudos to you on the great restore job. Looks like new.

[mro]

special grind cams

Too bad you guys are so far away, would be cool to get an in-person consultation...

Have yet to install the cams I got with the hot rod XS.
Still not sure how to optimize the adjustment for the slotted cam sprockets.

Finished the repair of the broken float post on the flat slide carbs and re-cleaned em.. (still sitting on work bench tho)


mro

[Dan Hodges]

Carburetor Air Flow Requirements

In response to Pggg's suggestion that I might find a horsepower increase by installing 36 mm carburetors,I submit the following. During this past winter I went through my engine for the second time since I have owned it and in so doing researched the carb thing pretty throughly. A 4 cycle engine with the cylinder displacement of one of Attilas cylinders, (17.97 CI) will pump 44 cfm @ 8500 rpm @ 100% volumetric efficency,(I'm using only one cylinder here).A 34 mm CV carburetor will flow 80 cfm @ 3 inches of mercury with the vacum slide fully raised. There are some variables to this which are,the slides are not completely raised untill about 4500 rpm,only highly tuned race motors can attain 100% V.E. and mine would be in the 85% range,I am seldom turning 8500 rpm but am most interested in 4000 rpm and up. 36 mm carbs from an FJ 1100-1200 Yamaha flow about 5% more than the 81 XS carbs which equates to about 2.5% more power @WOT if the motor can utilize it.I have a pristine set of early FJ carburetors however the FJ used double throttle cables like an XJ and they have no provision for the vacum advance pickup/sensor on the # 2 carburetor like the one on the XS.Of course with some fiddling the throttle cable deal could be resolved and the # 2 carburetor could be modified to accept the vacum advance pickup or it could simply be rendered inoperative if this was a race bike because in that application it would not be needed.In addition to all of this,the XS airbox is restrictive even for 34 mm carburetors and would be even more so for the 36 mm mixers which would require pod filters.Untill someone can show me an A to B dyno test where the 36 mm carbs made at least 3 horsepower more than the 34's from 5000 rpm up,I feel I have made the correct decision in keeping the 34's. The hot setup for a modified Eleven is a set of 33mm Mikuni smooth bores but they are a pain in the rear on the street.If I were turning this thing 9500 rpm-10000 rpm then 36 mm mixers would be in order but my self imposed limit is 8500 rpm-9000 rpm for $$$$$ obvious reasons.Actually one of these things needs some work on the crank counterweights and the flywheel lightened along with some Crower light weight rods,but personally I have spent way too much money on it already and so I shall leave those things to someone else.

[mro]

Hi Dan

It's been post here or on the UK site that "sling shot" carbs/pod filters on a stock XS has giving em 10+ HP.

So is this just so much smoke............


mro
BTW
most XSelent tech you provide
Been pasting it into my XS log