Strada Camshaft Oil Ways

[Duccout]

Thanks guys. I now have to decide whether to modify the cables that I have, or try to sell them on eBay and make up new ones. I had hoped that the cables would just be a straight fit, saving me hassle, but it has turned out to be double. No-one said it was easy!

Colin

[Duccout]

I've ordered some stepped ferrules from Venhill, which will hopefully allow the cable to fit.

Colin

[Duccout]

I have a new front brake cable! It was quite a palaver - I had to drill out the hole in each threaded adjuster to take the 2.5mm cable, and I had to cut the outer a third of the way down to insert the stop switch, and again to get the length right; I used a cutting disc in the Dremel for this, but the front brake is certainly smoother and feels more rigid, so I'm looking forward to a road test. The new 2.5mm cable and 7mm sheathing is much more substantial than the old cable.

Colin

[Duccout]

Here is a post especially for Bill!

Went out to try the new front brake cable - fantastic, much better. Went on my longest ride yet, and for the first time was able to ride the bike and relax and enjoy it. Stopped at a cafe and had a good chat with various guys who were interested in the bike, went to leave, kicked the engine over and it backfired and would not start. Kicked it a few more times, then saw that the carb had blown off the manifold! Couldn't fix it with an audience, so pushed it around the corner and luckily was able to get the carb back on without too much hassle. The ignomy.

Colin

[themoudie]

Treat it as a jocular event Colin!

I now carry a suitable short stubby screwdriver and plug spanner at all times for just such events. It appears that if the mixture is a tad on the lean side, the engine is more prone to backfiring and blowing the carb off! George (Blethermaskite) is now chuckling, as he doesnt have that problem with his AMAL MKI bolted to the head.

Changing down on a multi-lane, traffic light controlled roundabout had me in a similar situation in the middle of three lanes! Hold the hands above the head and dismount then cautiously move to the verge to put it back together, all the while hopeing that fuel isn't spilling on the exhaust!

Whether E10 is contributing to this phenomena I do not know?

Keep running the wee dodger anyway.

Good health, Bill

[blethermaskite]

Colin.......isn't it extraordinary just how much difference a new front brake cable makes . Bill I am only having a 'larf' in sympathy with this exploding carb phenomenon which as you rightly note I have almost nil experience of......and do you know you might just have a point there with the e5/e10/unleaded fuel, as I think I said before I'm not at all sure what that stuff they sell as petrol now is? but it certainly is not the stuff I used to run my Ducati's on in the 1970s (some with rubber mounted carbs ).
Cheers,
George

[Duccout]

Here is a convoluted question for everybody: ever since I got this bike running it has refused to rev, even after I sorted out the high rev mis-fire, it still reaches a point (probably 4-4.5 thou RPM) where it just runs rough and won't go any higher. This is not a problem as I only use it on small back roads, and I tuned it for torque (small valves, white cam, small carb and low compression). However I would like it to run properly, even if I don't use the revs.

I have obviously tried different main jets, which made no difference, so before ordering different sizes I thought I would try it without an air filter - problem solved! So, normally the engine is fitted with a K&N, via a 90 degree bend plastic pipe which is connected to the carb by a piece of radiator hose; the bend is necessary to clear the frame on the Mototrans. Now, is the bend in the tube causing the problem, or is it the filter itself? Back in the seventies help pages in the motorcycle mags were full of people having trouble after ditching standard air filters on their Japanese bikes and fitting K&Ns, and the advice was always that Mikunis will not run properly with pod filters.

So, back to my question: should I just ditch the filter and run with an open bellmouth, or try to find a better way of attaching the filter? Incidentally, does anyone know of a source for large bore, flexible rubber pipe that I could use to attach the filter? Radiator hose is too stiff.

Thanks,

Colin

[blethermaskite]

Colin,
Try your local motor factors for steering rack bellows, I have used these with success in the past, they are designed to work with all sorts of oil and seem to be petrol proof (though it might be a bit of try it and see with E10 ).
I wouldn't fit an air filter anyway I feel that all types strangle most bevel singles at the higher rev ranges, and as for K&N filters only fit for the bin .
Cheers,
George

[themoudie]

Aye Colin,

I'm with George on this, in that I have never run an air filter on the '74 450 MKIII, once the original bellows hose between the air filter in the side panel and the Dellorto VHB29 split in 1976. Dellorto carbs were a bit of a mystery; still are, and the Amal MKI 932 was cheap, available and made sense. So, the air filter came out, as did the split hose and the Amal went on, with the inlet port opened up to match the carbs 32mm ID. The change certainly allowed the engine to rev more freely in the upper half of the throttle opening. Once the contents of the exhaust blew out, due to corrosion, the willingness to rev was even better. Your 90° bend is unlikely to make for a good airflow, upstream of the carb. I appreciate that an eddying airflow after the carb helps keep the air/fuel mixture mixed before entering the combustion chamber, but the physics of it are beyond my ken.

I have found that with my Yamaha SRX600 engines, running the standard carburettor, fitted with a Stage3 needle kit and the K&N replacement air filter in the still air box beneath the seat and a free flowing absorption silencer, not to be a problem and allowed the engines to rev more freely than the standard air filter and silencer box. Running without an air filter in the still air box caused weak mixture problems and running with K&N pod filters and no still air box made tuning the lower half throttle range difficult to obtain a smooth pickup. I should add that a friend running a similar motor using a 40mm single carb from a Suzuki DR650, K&N pod filter and a homemade 1 into 2 alloy inlet tract finds that this has cleaned up the carburation right through the rev range and made the engine much more responsive, with no change to the standard Suzuki jetting

My homemade silencer element (MOTAD sketch), installed in the gutted Gold Star exhaust shell, does not appear to impede the revs, but definitely cuts the "crack" off the exhaust note and makes the lower half of the throttle opening mixture easier to tune and achieve smooth running. Many might think that cobblers, but I don't have a dyno to prove it one way or the other!

Whilst George prefers the long inlet trumpet on his Amal MKI, I used the standard short plastic trumpet on the 450, with the Amal 932 and had no problems. I also believe that with the Amal MKII 2932, when fitted with a short, wide OD trumpet, the engine performance is improved at larger throttle openings. I have found that the standard short inlet trumpet on the Amal MKII 2932 is perfectly adequate for my needs. Maybe there is a still air box effect, with this design of inlet trumpet.

Keeping the standard final drive ratio at 2.67:1 I have found to be more of a problem. Having the engine revving at 5,000rpm in 5th gear at 60mph isn't my idea of fun. I know there is another 2,000rpm to go, at least, BUT, HGV's on dual carriageways keep shoving me along with their "bow washes"! However, for back lane pottering, with cruising at 50mph to 55mph, the 2.67:1 ratio is fine.

Having changed from 530 to 428 drive chains and used a 13 tooth engine sprocket to a 32 tooth rear sprocket, with 530 chains (2.46:1), rather than standard 12 tooth engine sprockets (2.67:1). I shall be changing from the current 16 tooth engine sprocket and 42 tooth rear sprocket, 428 chain size (2.63:1), to something giving a ratio between 2.46:1 and 2.5:1, with a 17 or 18 tooth engine sprocket in place. So, an 18 tooth engine sprocket and either a 44 or 45 tooth rear sprocket is my likely fitment.

My apologies for the ramble, pick out the bits that you find applicable and I stand to be shot at dawn.

Good health, Bill

[Duccout]

Thanks Bill and George. I will leave the air filter off until I can find a straight way of attaching it. I took the plug out after my ride yesterday, and for the first time the colour was perfect, and not sooty.......

Bill, your gearing prevails are probably what we all go through, and I would say that we all set our gearing on the road to what we prefer, not maximum speed that the engine will pull. The standard 450 gearing is way too low, and a 13t gearbox sprocket is essential with the 530 chain, and it is probably best to switch to 428 and get the gearing up to something comfortable. My 450 was a great bike and I wish that I had not sold it, but that goes for all of my Singles and my 750 Sport. Hindsight...........I agonized over what gearing to put my 250 on, and decided on 16/47, with the Mototrans higher primary ratios, but even on the back lanes it was revving too much, so I bit the bullet and went up two teeth on the gearbox sprocket, which made the bike much more pleasurable to ride, and next time I will go for 18/45, which I think will be as high as possible without struggling to pull away.

My engine is very softly tuned, so has a wide spread of power, but a tuned 250 would probably struggle on my gearing.

I have to say that my 250 is a terrific little bike and considering that I haven't restored it, just made it roadworthy at the lowest price possible, it runs like a new bike. I can never put my finger on why Ducati Singles are so great to ride, but possibly it is due to the light weight, torquey, responsive engine, fine steering and that thumping exhaust note in the background.

Colin