Anyone know this bike???

[Teckhardt]

Posted on Advrider.com under cafe racers. Curious about a few mods on it.




http://www.advrider.com/forums/showpost ... tcount=867

[DewCatTea-Bob]

" Curious about a few mods on it. "

____ Off-hand, all I can tell is that it appears to be a 1974 450-Scrambler, possibly a '73 Canadian version?

-Bob

[carbcleaner]

Hi, new here, I've been lurking for a few weeks and just found this picture of me and my bike so thought I would reply. The bike is a 71' 450 not sure what market, the speedo is in kph and was last registered in Michigan in 74'. The carb is a dellorto PHF 36 mounted to a custom (originally straight, cut out a wedge re-weld) harley manifold and carefully matched to the head. The frame bracing had to be modified just slightly, I filed a 1/4 inch (or so) notch to clear the screw that fastens the top on the Dellorto. I could have modified the manifold so the carb would completely clear the frame but I wanted to keep it as close as possible (not stick out crazy and hit my knee). Other mods include, green/white cam, Dyna ignition, freer flowing exhaust, 12 volt electrics w/ small ni-cad battery and HID headlight. Also I fit a twin leading shoe brake from a 71' yamaha 650, machined out the speedo drive and modified a place for a CEV speedo drive, the brake stops real well and the speedo is quite accurate. The rims are 1974 flangeless NOS Akronts 18" F/R laced by me with stainless spokes and trued on my park bicycle truing stand. There is more- custom rear-set brake lever, Tommaselli clip-ons, Tommaselli speed throttle and lots of small stuff.
The Ducati has been clocked by a few modern bikes on a straight flat road w/ NO tail wind at 109 mph's (175 kph on the original 180 kph CEV speedo). It stops and handles better than I could imagine and the vibes that I read so much about are very minimal and have never bothered me even on a couple 100+ mile rides (that is taking into consideration my other ride is a late 71' preproduction Ducati 750 gt -very smooth).
Both bikes live inside the house, even my wife thinks they are beautiful. Ride safe but fast -Carl

[Teckhardt]

Carl:

Wow, I finally got some answers about your bike. Saw it on ADVRider over a year ago.

Going to PM you with my email address. Would love to get more details about the front brake and a few other items.

[DewCatTea-Bob]

" Hi, new here, I've been lurking for a few weeks and just found this picture of me and my bike so thought I would reply. "

____ Welcome as our newest listed-member, Carl ! _ Glad that you've finally come forth & laid-claim to your very-fine/mystery Duke !


" The bike is a 71' 450 not sure what market, "

____ Could you please post any other pictures you might have of it from before you altered anything, back when it was more stock ?
It appears to be too new of a Duke-model to be a "71"... Would you mind telling us at least the first 4-digits of it's motor-number ?


" The carb is a dellorto PHF 36 mounted to a custom (originally straight, cut out a wedge re-weld) harley manifold "

____ The 36mm version -(the largest) of that carb-model, is a good size choice for the 450-engine, however that large-bodied carb-model is next to impossible to get mounted very nicely ! ...
It would be nice to know some more about the particular manifold which you chose for your mounting-job.


" Other mods include, green/white cam, "

____ I have also done this, and have mentioned about it within another thread ! _ If you happen to come-upon that thread, then how about adding your own opinions about how that G&W-cam has affected your 450's performance !?


" Dyna ignition, 12 volt electrics "

____ It'd also be nice of you, (should you get the time), to mention some details concerning these modifications which you've got done on your unique Duke !


" The Ducati has been clocked by a few modern bikes on a straight flat road w/ NO tail wind at 109 mph's (175 kph on the original 180 kph CEV speedo). "

____ Could you please tell us the size of your rear-tire and what sprockets you have on your 450 ? - (Stock sizes should've been 3.25x18, with 32 & 12t.)


DUKE-Cheers,
-Bob

[carbcleaner]

Hi Bob,
Here are a few answers to some of your questions:

I'm pretty bad about pictures but it looked just like the picture of the 69' Ducati 450 scrambler on page 78 of Standard catalog of Ducati motorcycles by Ian Falloon. The only differences I could pick out would be mine has two gauges (both CEV w/ needles that spin clockwise and zero at two-o-clock) held together in a molded rubber mount and the air filter was slightly different. The first four digits of the engine number are DM 450 45283## and the frame DM 450S *4615##*.

Yes the carb was a pain to get mounted "nicely" but I must say it came out very well. The carb has the spigot and the manifold slips in and clamps tight, it basically clears the frame. The only mod was a 1/4" or so notch in the bracing to miss the screw that holds down the cover on top of the carb. The G/W cam works a treat, the bike starts first kick most every time, pulls away hard and as I said hit well over 100mph. The bike also seems to get great fuel economy, around 50mpg and even idles great.

The Dyna ignition was sourced on ebay for cheap, it was set up for a four cylinder Suzuki so I only used one of the two pick-ups. I cut down the mounting plate to fit and shimmed the points cam to fit the rotor (a bit of work but works and looks perfect). As for the 12 volt conversion, I chose the low-brow route and simply added a $12 12 volt voltage regulator to the two yellow wires. After reading some of your suggestions about alternate methods I'm sure I'll tackle the job soon, seems a waste to produce more power than I need...

The gearing I believe is stock but I counted 35 teeth and not sure what the front is, being under the cover and all. The tire size on the back is a Pirelli 110-90-18.

I've owned around 45 motorcycles (many BMW's,Norton's,Triumph's,Honda's,KTM's,Ducati bevels and belts,Laverda,Guzzi,Benelli,Can Am,Yamahas,Suzuki) over the last 23 years and the two that I've kept are both 71' bevels. You gotta love these bikes! Carl

[DewCatTea-Bob]

" The first four digits of the engine number are DM 450 45283## "

____ That number does correlate with being a 450SCR made by 1971.
What was your tip-off that "1971" was it's correct model-year ?
__ Did you not get any clue from the previous-owner as to what country it was originally marketed for and/or sold in ?


" The carb has the spigot and the manifold slips in and clamps tight, it basically clears the frame. "

____ I was hoping to learn specifically about the manifold itself... As you stated it was from a "harley" ? _ Was it already made to fit such a carb-model ? _ And how does it fit to the (stock?) mounting-bolts of the Duke-cyl.head, etc. ?


" The G/W cam works a treat, the bike starts first kick most every time, pulls away hard and as I said hit well over 100mph. The bike also seems to get great fuel economy, around 50mpg and even idles great. "

____ I was hoping you could confirm a bit about it as far as how it's performance-characteristics compare to the stock-cam. _ Such as, you should've noted that the engine became easier to kick-over, and noticed getting higher top-end & stronger mid-range power, at a slight expense of low-end take-off punch.
Had you not noticed anything of the sorts?


" The Dyna ignition was sourced on ebay for cheap,
I cut down the mounting plate to fit and shimmed the points cam to fit the rotor (a bit of work but works and looks perfect). "

____ Sounds like the way to go but, I'm wondering about that shimming-work you had to do, to fit the Dyna trigger-rotor onto the stock points-cam.


" As for the 12 volt conversion,
and simply added a $12 12 volt voltage regulator to the two yellow wires. "

____ Wondering about the regulator-unit you're using...
I assume you got that cheap on eBay as well but, what was it originally from? - Some Jap-bike ? _ If so, what model ?
__ And how has it been working-out for you? _ Have you used it for very long ?


" The gearing I believe is stock but I counted 35 teeth and not sure what the front is, being under the cover and all. "

____ The 450-Scrambler model started getting 35t (instead of 36t) rear-sprockets, some time after mid-1970. _ The front-sprocket remained 12t, (as far as I know) until 1974 when (I think) they started coming with 13t. - That provides a 2.69-ratio, which would be closer to what's needed in order to get up to 110-MPH, (than a 35/12 \ 2.91-ratio) !


" I've owned around 45 motorcycles
over the last 23 years and the two that I've kept are both 71' bevels. You gotta love these bikes! "

____ Indeed Carl ! _ And hopefully we can help you remain being the keen Duker which you must already be !


DUKE-Cheers,
-Bob

[carbcleaner]

Hi Bob, thanks for all the interest in my bike, I'll try and be more specific in my descriptions. I bought the bike as a complete (only missing the headlight) 71' 450 scr off ebay about 3 years ago. The Michigan title was issued in 71' and stated the bike was a 71' and the last registration was from 74'.

As for the "Harley" manifold, I bought the Dellorto carb w/ the manifold off ebay (I've used that resource a lot), the manifold was a straight 36mm ID tube w/ a flange welded to the end having two holes set for mounting to a harley intake. The manifold clamps into the carb w/out any rubber or hose clamps. I drilled two new holes for mounting up to the ducati head, the holes were so close to the originals I simply made them oval and cut and re-welded the manifold as described in my first post. The whole manifold looks very good almost like it was designed for this application.

I don't have much to compare the new cam w/ the old, I only ran the old cam set up for about 10 miles and when I changed to the G/W I also installed the 36 dellorto, so we have a case of apples to oranges... The G/W cam seems to take about the same effort to start the bike (one or at most two kicks to get it going) as the original. The off the line power is definitely better as is the mid and top end. Wish I had a better comparison for you.

The dyna set up is great, I first used a dyna ignition on my gt 750 and it transformed the bike (easier starting, smoother, and more power, the best single improvement I made). For this bike I had to modify the unit, the "shimming" I used was simply a press fit bushing drilled to fit over the points cam then I drilled and tapped a hole in the side for a grub screw to make sure there would be no movement. It looks factory and works perfect.

The regulator I used, I bought off ebay, it was new and designed for a chinese go cart. The reg. has 5 wires, green, black, red, yellow and pink, the yellow and pink connect to the two yellow wires from the alternator (the rest are obvious) and it works great.

The gearing seems to be stock, I counted 12 teeth on the front with a magic marker and a flashlight and as stated 35 teeth on the back. 109 mph seems real, I trust my friends but we could all be off a little, either way it's fast and fun...

I realized my math was off, I have been into motorbikes for 30 years not 23, how time flies....
Thanks again for the interest. Carl

[DewCatTea-Bob]

" The Michigan title was issued in 71' and stated the bike was a 71' and the last registration was from 74'. "

____ Since the 450-Jupiter/Scrambler-model wasn't imported into the U.S. after 1970 and you pointed-out that the speedo-dial was in KPH (instead of MPH), I had assumed that your 450 had come from another market. _ But now I'm thinking it's possible that the entire front-end is off another bike and that your 450SCR is actually a held-over model-year, which may have actually been made in late 1970.


" As for the "Harley" manifold, I bought the Dellorto carb w/ the manifold
the manifold was a straight 36mm ID tube w/ a flange welded to the end having two holes set for mounting to a harley intake. The manifold clamps into the carb
I drilled two new holes for mounting up to the ducati head, "

____ Okay Carl, I now get the full-picture... You didn't have to 'come-up' with a manifold to fit your particular carb, as they were actually a pre-matched set-up (intended for a Harley-Sportster, or the like), thus making your fitment-project that much less troublesome !
This being the case- (that the carb was intended to feed 4-stroke 450/500cc cylinders), means that the pre-existing jetting was already close enough to try-out as it was...
So have you made any further jetting adjustments to it ?
__ This information you've given, should be fairly helpful for anyone else who's been interested it fitting these large-bodied carbs to their Duke !


" The G/W cam seems to take about the same effort to start the bike (one or at most two kicks to get it going) as the original. "

____ By "kick-over", I wasn't referring to the difficulty in getting it started,, rather I meant that getting the engine past TDC (without use of the comp.release), should've then become notably easier !


" The off the line power is definitely better as is the mid and top end. Wish I had a better comparison for you. "

____ I'm quite certain that should you come to run against a stock 450-Scrambler, and engage in a high-gear/low-speed roll-on contest, you'll then see the stock-450 walk-away from you, and maintain it's lead until at least 80-MPH.


" The regulator I used, I bought off ebay, it was new and designed for a chinese go cart. "

____ Are there any more of those to be found on eBay and be had for the same "$12" price ?
__ And if you don't do too much city-driving type riding in town at night, then you should find that connecting it's pink-wire to your wide-case alternator's Red wire-lead, should be sufficient (even though then only half the power).


" The gearing seems to be stock, I counted 12 teeth on the front "

____ Did you have any good tach-readings up there above 100-MPH ? _ With that low of gearing (35/12t), the engine would've had to have been spinning at over 8k-RPM !
If I knew exactly how much your rear-wheel's radius differed from 26-inches, I could then do the math to figure the exact number of revs required to obtain 109-MPH.
If you're at all interested to know, then simply dab a wet-spot onto your rear-tire's tread, and then let me know the distance* you measure between two spots transferred onto the (smooth) pavement, from your straightly rolled wheel. - (* Should be between 77 to 87 inches, [I'd guess about 82.5-inches for your particular tire-size].)


___ Thanks for supplying (most all of) us here, with another interesting post to read, Carl !


DUKE-Cheers,
-Bob

[MotoMike]

Carl

I'm curious about the fitting of the throttle cable on the big carb. Wondering if there was trouble getting it to make the bend under the tank? Seems tight on my Amal and your DelO looks pretty big on there.
Mike